UWorld Incorrects Flashcards
What is the antidote for severe Serotonin Syndrome?
Cyproheptadine: 1st gen Antihistamine with nonselective serotonin antagonist (5-HT1 and 5-HT2)
How can you inhibit a shorter growth spurt in a child who is female who has Idiopathic precocious puberty?
Inhibit estrogen effects on long bone epiphyseal plate.
Describe Strep Agalactiae (GBS)
- Catalase negative
- beta hemolytic
- PYR negative (Pyrrolidony Arylamidase)
- CAMP positive (Christie, Atkins and Much- Petersen test)
- Causes neonatal sepsis, meningitis, UTI
Describe the E Coli virulence factor: P. Fimbriae
- allows adhesions to urothelium
- Presents as UTI
Gram negative bacilli, cannot ferment lactose, is not oxidase-positive, and can produce H2S:
Proteus and Salmenella
Gram negative bacilli, slow lactose fermenter:
Citrobacter and Serratia
Describe Strep Viridans
- Catalase negative
- Alpha- hemolytic (partial green hemolysis)
- Optochin-resistant
- Bile insoluble
- Found in dental carries
- Responsible for subacute endocarditis
Describe Strep Pneumoniae
- catalase negative
- optochin- sensitive
- bile soluble
- alpha hemolytic (partial green hemolysis)
- causes meningitis, otitis media, Pneumonia, Sinusitis
Describe Strep Pyogenes (GAS)
- catalase negative
- beta hemolytic
- PYR positive (Pyrrolidonyl Arylamidase)
- Bacitracin Sensitive
- Causes Scarlet fever, Rheumatic fever, and PSGN
Describe Enterococcus
- Catalase negative
- Gamma hemolytic
- Growth in Bile and 6.5% NaCl
- causes UTI, Cholecystitis, and subacute endocarditis
Describe Strep Gallolyticus
- catalase negative
- gamma hemolytic
- growth in bile, not in NaCl
- PYR-Negative
- responsible for Bacteremia associated with colorectal cancer
Describe the features of MHC II:
Structure: Alpha and Beta polypeptide chains
Location: APC’s (B-cells, macrophages, dendritic cells, langherans cells)
Type of Ag: Bacterial from lysosomes.
Antigen Presentation: Activates TH cells, when stimulated results in the humoral and cell-mediated immune response.
Describe the erythematous childhood rash: German Measles (Rubella)
- Caused by Rubella Virus ( Enveloped, ssRNA positive sense, Togaviridae family, Rubivirus genus)
- Clinical presentation: Maculopapular rash starting on head, progressing to trunk and extremities, also occipital and post-auricular lymphadenopathy.
- Complication: Congenital Rubella Syndrome
Dermatology Pathology:
Describe the Erythamatous rash in childhood: Roseola Infantum
- Caused by HHV 6 (Enveloped dsDNA, Icosahedral shape, Herpesviridae family)
- High fever for 3-5 days with rash after fever subsides. Macules and papule initially at truck that spreads to extremeties.
- Complications are self limited.
Describe Actinomyces Israelli
- gram positive bacterium that grows in filaments.
- causes a cervicofacial infection that slowly evolves into multiple abscesses and draining sinus tracts with yellow “sulfur” granules.
- Histopath: chronic inflammatory granulation tissue surrounding dense fibrosis.
Describe Statin Myopathy:
Myocyte Necrosis caused by increase concentration of Statin drugs, mostly due to Cyp450 inhibition. Severe cases rhabdomyolysis and AKI (elevated BUN and creatinine), dark urine.
Cyp450 inhibitors: Cyp3A4
- Non-dihydropyridine CCBs: Verapamil, diltiazem.
- Macrolides: Erythromycin, Clarithromycin.
- Protease Inhibitors: Ritonavir, Soquinavir)
- OATP inhibitors: Cyclosporine
- Corticosteroids, Fibrates, Colchicine, Ketoconazole
Statin of choice to prevent this is Pravastatin.
Describe Lichen Planus
Clinical findings:
- 5 ‘p’s’: pruritic, purple/pink, polygonal, papule, plaques
- Lacy, white network (Wickman Striae)
- Locations: Skin (e.g. wrist, ankles), oral mucosa/white papule and plaques and erythema, (mucosal cetrophy ulcers), Geritalia
*Path. findings: Hyperkeratosis, Lymphocytic interface dermatitis, Eosinophilic colloid (civatte) bodies, thickened stratum granulosum, sawtooth ridges Rete
*Hx: Chronic symptoms. Form. of Lesions at sites of trauma (Köbner phenom.) Resolve 2 yr. Mucosal recur./persist.
Describe the pathway of CSF
- Lateral Ventricles
- Interventricular foramina of Monro
- 3rd Ventricle
- Cerebral aqueduct of Sylvius
- 4th Ventricle
- Lateral foramina of Lusaka or midline of Magendie
- Subarachnoid space
Describe Syringomyelia:
- Formation of a cavity (syrinx) in the cervical region of the spinal cord.
- The syrinx damages the ventral white commissure, leading to BL loss of pain and temperature of the affected levels (typical arms and hands), distal sensation is preserved.
- Destruction of ventral horns results in flaccid paralysis and atrophy of the intrinsic muscles of the hand.
Describe Aplastic Anemia:
-Pathogenesis: Multipotent hematopoietic stem cells destroyed by cytotoxic T cells or direct cytotoxic injury –> bone marrow aplasia/hypoplasia –> lack of circulating peripheral blood cells.
*Common triggers: Autoimmune, drugs: cytotoxic chemotherapy, immunosuppresants, idiosyncratic reactions. Ionizing radiation and toxins. Viral infections (eg. viral hepatitis, HIV)
*Manifestations: anemia, thrombocytopenia, leukopenia.
Describe pure red cell aplasia:
Rare form of bone failure characterized by severe anemia with reticulocytopenia and morphologically normal platelets and leukocytes. Most common with Thymoma, Lymphocytic leukemia, and parvovirus B19 infection.
Describe IgA Vasculitis (Henoch-Schönlein purpura):
*Pathogenesis: Deposition of IgA immune complex in small vessels
- activates compliment.
- Neutrophillic inflame and vascular damage.
- often follows a URI
*Clinical Manifestations:
- Palpable purpura/petichiae on the lower extremities and
buttocks.
- Arthritis/arthralgia, abdominal pain, GI bleed intersusception,
renal disease (hematuria w/ w/o protein)
*Dx: Usually clinical
- Skin Bx: Leukoclastic vasculitis, IgA deposition in vessel walls
List the anomalies associated with Trisomy 21:
- Neuro: Intellectual disability, Early onset Alzheimer Disease
- Cardiac: Complete AV Septal Defect, VSD, ASD
- GI: Duodenal Atresia, Hirschsprung Disease
- Endo: Hypothyroidism, T1DM, Obesity, Short Stature
- Oncologic: Acute Leukemia (ALL)
- Orthopedic: Atlantoaxial instability
Describe Hereditary Angioedema:
- Recurrent episodes of cutaneous or mucosal swelling due to C1
inhibitor deficiency. - C4 levels are low due to inhibited cleavage of C4 by excess activated
C1 - Elevated bradykinin causes vasodilation and increase vascular
permeability resulting in edema.
Describe how chronic pancreatitis cause vitamin B12 deficiency:
What are the symptoms of chronic pancreatitis?
- Decreased production of pancreatic proteolytic enzymes (exocrine
insufficiency), needed to release vitamin B12 from the R protein. - Symptoms: chronic epigastric pain, weight loss, and steatorrhea
Describe Alkaptonuria:
- Autosomal Recessive
- Deficiency in Homogentisic Acid Deoxygenase, involved in tyrosine
metabolism - Excess homogentisic acid causes black-blue deposits in connective
tissues => sclerae and ear cartilage hyperpigmentation and
osteoarthropathy of the spine and large joints
What are the triggers for Reactive Arthritis?
*Preceding infection:
- GU: Chlamydia trachomatis
- GI: Salmonella, Shigella, Yersinia, Campylobacter, Clostridiodes
difficile
*MSK: Asymmetric Oligoartitis, Enthesitis, Dactylitis. Associated with HLA-B27
*Extraarticular symptoms: Ocular conjunctivitis, anterior uveitis,
genital-urethritis, cervicitis, prostatitis, dermal-keratoderma
(psoriasis-like bumps), blennorrhagicum, circinate balantis (red flat rash on penis), oral ulcers
Describe the Erythematous Childhood rash: Erythema Infectiosum
- Caused by Parvovirus B19 (NE ssDNA)
- Malar rash with ‘slapped cheek’ appearance
- Complications: aplastic crisis in sickle cell and immunocompromised
patients
Describe the Erythematous Childhood rash: Scarlet fever
- Agent: Strep Progenies (GAS)
- Sandpaper like rash that begins on the neck and upper trunk and
then generalizes. - Associated with fever and sore throat
- Complications: Rheumatic fever, glomerulonephritis
What comprises the arterial supply of the ureters?
- Renal artery supplies the proximal ureter
- Superior vesical artery supplies distal ureter
Describe the Erythematous Childhood rash: Measles (Rubeola)
- Agent: Measles virus (Enveloped ssRNA negative sense,
Paramyxoviridae family) - Macularpapular rash starting at the head, the spreads to the trunk
and extremities. - Rash precedes by cough, coryza, conjunctivitis, and Koplic Spots.
- Complications: Bronchopneumonia, Encephalitis
Describe the E. coli virulence factor K1 capsular polysaccharide:
What can it cause?
- Mechanism: prevents phagocytosis and compliment-mediated lysis
- Presents as Neonatal Meningitis
What does an increase in acetylcholinesterase on amniocentesis suggest?
Leakage of CSF into the amniotic cavity. Suggestive of an open neural tube defect. Occurs from failed fusion of the edges of the neural plate.
List the antibiotics effective against Pseudomonas Aeruginosa:
- PCNs: Ticarcillin, Piperacillin
- Cephalosporins: Ceftazidine (3rd gen), Cefepime (4th gen)
- Aminoglycosides: Amikacin, Gentamicin, Tobramycin
- Fluoroquinolones: Ciproflaxicin, Levofloxacin
- Monobactams: Aztreonam
- Carbapenems: Imipenem, Meropenem
*Hint: Burn patients
What is the pathogenesis in Ehlers-Danlos Syndrome?
Defective collagen synthesis due to deficient procollagen peptidase. Impairs removal of N-terminal propeptide.
Describe Tuberous Sclerosis:
*Pathogenesis:
- Autosomal dominant
- TSC1/TSC2 tumor supressor gene mutation => Defective tubers-
hemartin complex => unrestricted cellular proliferation
Classic finding:
- Skin: Ash-leaf spots, facial angiofibromas, Shagreen Patches
- Neuro: CNS Hemartomas, Seizures, Intellectual disabilities
- Cardiac: Rhabdomyomas
- Renal: Angiomylipomas
What structures are derived from Endoderm?
- GIT, Liver, Pancreas
- Lungs
- Thymus, parathyroids, thyroid follicular cells
- Middle ear epithelium
- Bladder and urethra
- Parafollicular (C) cells
Describe Pompe Disease:
Type 2 Lysosomal Storage disease
*Deficiency in acid alpha-glucosidase
- normal glucose levels
- severe cardiomegaly
- glycogen accumulate in lysosomes
Describe the MOA of Azole antifungals:
Blocks fungal enzyme Lanosterol 14-alpha-demethylase (Cyp450 dependent) for Lanosterol => ergosterol conversion.
- Mutation in genes => fungal resistance
Describe Vitamin E deficiency:
Etiology:
- Fat malabsorption: Cystic Fibrosis, pancreatitis, cholestasis
- Genetic: abetalipoproteinemia
Clinical features:
- Hematologic: hemolytic anemia
- Neuromuscular: Spinocerebellar tract: ataxia, Dorsal columns:
Loss of vibration and proprioception, Peripheral nerves:
decreased strength and sensation hyporeflexia.
- Muscles: Myopathic weakness
*Tx: High dose Vitamin E
What would you expect in a patient with aortic regurgitation caused by infective endocarditis?
- Rapid loss of aortic pressure during diastole
- Eccentric hypertrophy due to increase EDV
- Increase in SV and CO
- High amplitude, rapid rise- rapid fall pulsation => widened pulse
pressure - Corrigan sign: rapid distention and collapse of carotids
- Duroziez sign: ‘to-and-fro’ bruit appreciated at the Femorals.
- Aortic pressure: 160/60; LV pressure: 160/20.
-Reduced aortic diastolic pressure and elevated LVDP (diastolic back
flow). Aortic and LVSP increased from compensation.
Describe Turner Syndrome:
- Loss of a paternal X chromosome (45, XO)
- Physical Features: Short stature, broad chest, and webbed neck.
May have a narrow, high-arched palate, low hairline, cubits vulgarus (elbows with a weird angle). - Cardiac: Bicuspid AV, Aortic Coarctation in which causes an
increased risk of aortic dissection - Renal: Collecting system malformation (Ureter Duplication),
Horseshoe kidney (fusion of lower poles) presented as Recurrent UTIs. - Repro: Streak Ovaries (amenorrhea, infertility)
Describe the Latissimus dorsi:
- Contributes to forceful movement of the humerus
- Innervated from the thoracodorsal nerve (C6-C8)
- Extension, adduction, and internal rotation of the humerus
- injured from forceful downwards movement of the humerus,
throwing, climbing, or swinging
Describe Narcolepsy:
DSM 5 Criteria:
- Dx: recurrect lapses into sleep or naps (> 3/wk for 3 months)
- more than or equal to 1 of the following:
*Cataplexy: Brief loss of muscle precipitated by strong emotion
(laughter or excitement)
* Low CSF levels of hypocretin-1 (orexin-secreting hormone)
* Shortened REM latency
- Associated features: Hypnagogic/hypnopompic hallucinations, sleep
paralysis
Describe Pierre Robin Sequence:
*Single developmental defect causes a cascade of additional malformations
=> micrognathia, glossoptosis (small mandible displaces tongue posteriorly), U-shaped cleft palate (posterior displacement of the tongue prevents palatal fusion)
Describe Mucormycosis:
- Opportunistic infection caused by Rhizpus, Mucor, and Absidia
species. - Paranasal sinus involvement in DM and Immune suppressed
patients. - Broad nonseptate hyphae that branch at right angles
What are the primary cells involved in hepatic fibrosis?
- Stellate (Ito) cells
- Hepatic injury => stellate cells activated => Myofibroblasts
proliferate, promote chemotaxis, and producing lots of collagen. - Masson trichome stain
What is equation for relative risk?
RR= (a/a+b)/(c/c+d)
Describe the effect of chronic glucocorticoid use on the HPA axis for cortisol:
Decreased Corticotropin Releasing Hormone (CRH) -> Decreased ACTH -> Decreased Cortisol
Describe Leishmaniasis:
-Intracellular protozoa with rod-shaped kinetoplasts causing
cutaneous lesions.
- Endemic in Middle East and Central/South America
- Transmitted through bites of infected sand flies
- Protozoa mature in macrophages
What virus has lifelong latent infection of the sensory ganglia, has periodic viral replication leading to cycling flares that resolve over time?
HSV- Latent infection within neuronal cell bodies.
Describe the antipsychotic side effect: Neuroleptic Malignant Syndrome
Fever, rigidity, mental status changes, autonomic instability
What structures are derived from the neural tube (ectoderm)?
Brain, spinal cord, posterior pituitary, pineal gland, retina
What structures are derived from the surface ectoderm? Mneumonic: A LINE
- Anterior Pituitary (Rathke pouch)
- Lens and Cornea
- Inner ear sensory organs, olfactory epithelium
- Nasal and oral epithelial lines, salivary glands
- Epidermis, sweat and mammary glands
What is the key feature in congenital HSV?
vesicular/ulcerative rash
Describe Congenital Toxoplasmosis:
Infection acquired in utero that can present with hydrocephalus, intracranial calcification, and chorioretinitis due to CNS inflammation
Describe Measles Virus (Rubeola)
- Clinical Presentation: Prodrome (Cough, coryza, conjunctivitis, fever,
Koplik spots), maculopapular exanthem
- Cephalocaudal and centrifugal spread
- Spares palms and soles - Complications:
- Primary Measles pneumonia
- Secondary bacterial infections (pneumonia and otitis media)
- Neurologic: Encephalitis (days), Subacute sclerosing
encephalomyelitis (weeks), Subacute sclerosing Panencephalitis
(years)
- Prevention: Live Attenuated Vaccine
*Increase risk with Vitamin A deficiency
What can a patient develop preceding Panic Disorder?
Agoraphobia: avoidance of multiple situations where they may feel trapped and helpless. Can be dx w/ for w/o panic disorder.
Gram negative bacilli, cannot ferment lactose, is not oxidase positive, and cannot produce H2S?
Shigella and Yersinia
MSK Anatomy:
What are the hip flexors?
- Rectus femoris (also does knee extension)
- Iliopsoas
- Sartorius (also does knee flexion)
Drug(s) of choice for HIT?
Direct thrombin inhibitors: Hirudin, Lepirudin, Argatroban. Does not require ATIII.
Antidote for Warfarin overdose:
FFP and Vitamin K
Antidote for Heparin overdose:
Protamine
Homozygous for the apolipoprotein E4 allele. What is the most likely pathology to develop?
Late onset Familial Alzheimer’s Disease
Describe Transudate Pleural Effusion:
- Light Criteria: Excudate criteria not met
- Pathophysiology: Change in hydrostatic or oncotic pressure.
- Common causes: Heart failure, cirrhosis (hepatic hydrothorax), nephrotic syndrome
What structures are derived form the mesoderm?
- Muscles
- connective tissue, bone, and cartilage
- Cardiovascular and lymphatic systems
- Spleen and hematopoietic cells
- Kidneys and ureters, internal ganglia
- Adrenal cortex
Prolonged exposure to loud noises causes hearing loss due to damage to what?
Stereocilliated hair cells of the organ of Corti
Describe the mechanism of action of patiromer?
- Exchanges calcium for potassium in the intestine. Decreases
Potassium excreted in the feces. - AE: Diarrhea, hypokalemia, hypercalcemia, and hypomagnesemia
Of the respiratory tree, what is the last to disappear?
Cilia, persists up to the respiratory bronchioles.
Describe the Abducens Nerve:
- CN VI, innervated Lateral rectus. Function to abduct the eye.
- Lesion would cause medial deviation. Horizontal diplopia
What are the components of a maternal serum quadruple screen?
AFP, estriol, beta hCG, and inhibin A
What conditions cause an increase in Maternal serum AFP?
- Open neural tube defects (eg, anencephaly, open spina bifida)
- Ventral wall defects (eg, omphalocele, gastroschisis)
- Multiple gestation
What conditions cause a decrease in Maternal serum AFP?
Aneuploidies (eg, trisomy 18 and 21)
Describe the features of fragile X syndrome:
- Pathogenesis: X-linked disorder caused by a trinucleotide (CGG) repeat expansion in the FMR1 gene (fragile X messenger ribonucleoprotein). Repeats with more that 200 causes hypermethylation, which silences the gene and prevents transcription of the associciated ribonucleoprotein.
- Physical features: Long, narrow face, a prominent forehead and chin; and large testes. Most apparent after puberty. Hyperlaxity of the joints in the hand can also occur.
- Cognitive and Developmental: Developmental delay (speech and motor) common in infancy. Intellectual disability can vary.
- Neuropsychiatric: features of ADHD (eg, inattention, impulsivity) and autism spectrum disorder (eg, poor eye contact, social deficits) are common.
Vignette mentions a skin nodule that stains dark-blue, basaloid keratinocytes in the dermis with peripheral palisading and cleft formation. Cells are crowded, have scan cytoplasm, and have a high N:C ratio. What is the Dx and what is the most likely outcome?
Dx: Basal cell carcinoma
Outcome: Local growth with progressive tissue destruction.
Neuroanatomy:
List the most common causes of Spinal stenosis: 3
- Intervertebral disc herniation
- Ligamentum flavum hypertrophy
- Osteophyte formation affecting the facet joints
Describe Holoprosencephaly:
- Embryology: Incomplete division of the forebrain (prosencephalon)
- Etiologies: Genetic: Trisomy 13, Sonic Hedgehog gene mutations;
Environmental: maternal alcohol use, retinoic acid deficiency - Clinical features: CNS abnormalities: range from asymptomatic to seizures, severe intellectual disability, death.
Midface abnormalities: range from mild hypotelorism (distance between the eyes) and cleft lip/palate to cyclopean, primitive nose, facial cleft.
Describe Permissiveness:
Occurs when a hormone has no direct effect on a physiologic process but allows another hormone to exert its maximal effect on that process.
Example: Cortisol exerts a permissive effect on catecholamines to potentiate vasoconstriction and bronchodilation; it also has a permissive effect on glucagon to increase glucose release from the liver.
An increase in which of the following features best explains the presence of Target cells?
Increase in Surface area-to-volume ratio. Occurring from either a reduced erythrocyte cell volume from deficient hemoglobin synthesis (thalassemia, iron deficiency) or structural mutation to hemoglobin (eg, sickle cell)
Or excessive erythrocyte cellular membrane due to greater cholesterol-to-phospholipid ratios (eg, Obstructive liver disease) or splenectomy.
Describe Pappenheimer bodies:
Aggregated iron deposits in erythrocytes that are often seen in patients with sideroblastic anemia. They appear as dark blue inclusions.
Describe Howell-Jolly bodies:
Clusters of DNA remnants in erythrocytes due to hyposplenism or asplenism (the spleen usually removes the DNA remnants). They appear as peripheral, round, dark purple, blue, or red inclusions.
Describe Heinz bodies:
Aggregates of denatured hemoglobin that may be present in erythrocytes when patients have Glucose-6-phosphate DH deficiency or thalassemia. Cannot be seen on routine screening.
Describe Basophilic stippling:
Blue granules dispersed within the cytosol of erythrocytes due to precipitated ribosomes.
- thalassemias
- alcohol use disorder
- lead/heavy metal poisoning
Describe the immunosuppressants in transplant patients Cyclosporine and Tacrolimus:
Inhibit calcineurin activation. Calcineurin is an essential protein in the activation of IL-2, which promotes the growth and differentiation of T cells.
What medication is know to have a lower incidence of tornado de pointes than other QT-prolonging agents?
Amiodarone
Which cells control a Tuberculosis infection?
CD4 T lymphocytes and macrophages
ST elevations in (lateral) leads I and aVL, which cardiac artery is affected?
Left circumflex artery
Which leads have ST elevations when it affects the Left Anterior Descending Artery (LAD)?
Proximal: anterior leads V1-V4
Distal segment may spare V1-V2.
Which leads have ST elevations when the Left Main Coronary Artery is affected? (giving rise to the LAD and LCM)
Anterior V1-V4 and lateral V5-V6 and aVL leads.
What additional tests should be considered during a workup for acute pancreatitis?
Serum Triglycerides (more than 1000 mg/dL
Describe the three treatment of cyanide (CN-) toxicity:
- Sodium thiosulfate: sulfur donor that facilitates CN- binding to form thiocyanate, which is excreted in the urine.
- Hydroxocobalamin: Cobalt binds to CN- to form cyanocobalamin, which is excreted in the urine. Prevents cyanide binding to ferric ions.
- Sodium Nitrite: Nitrites promote formation of methemoglobin, which binds CN- with greater affinity than cytochrome C oxidase, reducing CN- toxicity. Take with caution because Methemoglobinemia is toxic in excess.
Describe Campylobacter Jejuni:
- Epidemiology: Motile, curved, gram-negative rod, oxidase-positive.
Transmission: contaminated food (undercooked poultry) and pets (dogs).
Common cause of food borne gastroenteritis. - Manifestations: Fever, abdominal pain, diarrhea w/ w/o blood/mucus. Usually self-limited (<7days)
- Complications: Guillain-Barré syndrome (cross-reacting antibody to myelin gangliosides)
Reactive arthritis.
What is impaired in Osteogenesis Imperfecta?
Osteoid production by osteoblasts.
Formula for Odds Ratio:
Odds of dx of cases/ odds of dx of control.
OR= (a/c)/(b/d) or (ad)/(bc)
Levels of which of the following substances will be higher in the pulmonary vein compared to the pulmonary artery in Decompensated heart failure? (exertion dyspnea, orthopnea, JVD, cardiac heave, and peripheral edema)
Angiotensin II
Describe Dysplasia type of congenital anomaly?
- Abnormal organization of cells within a tissue (often genetic)
- Ex: Skeletal dysplasia (eg, achondroplasia)
What is responsible for internuclear ophthalmoplegia (impaired adduction with CL eye gaze) and optic neuritis (transient blur in vision and eye pain with movement)? What is the dx?
Demyelination of CNS (reduced saltatory conduction) in AI-Multiple Sclerosis
Describe Intraductal Papilloma
Epithelial and myoepithelial cells lining fibrovascular cores in a cyst was or duct. Causes bloody nipple discharge and typically present without breast masses or skin changes.
What is the difference between factor X (hematin) and factor V (NAD+) in Haemophilus influenza?
- X factor Hematin responsible for beta-hemolysis-induced erythrocyte lysis
- V Factor (NAD+) is responsible for growth
Describe the Trochlear Nerve:
- CN IV, innervates the superior oblique Fx to abduct, internally rotate, depress the eye while adducted
- Lesion cause upward deviation, vertical and torsional diplopia
List the key features of congenital syphillis?
Rhinorrhea, Skeletal anomalies, Desquamating rash (palms/soles)
Which inhibitors block binding of platelet glycoprotein IIb/IIIa with fibrinogen and fibronectin?
- GpIIb/IIIa inhibitors: Abciximab, Eptifibatide, Tirofiban
*Useful in percutaneous intervention (PCI) in ACS
Formula for oral bioavailability:
AUC of PO dose/ AUC of IV dose
Describe E coli virulence factor Lipopolysaccharide:
How does it present?
- Mech: Activates macrophages -> widespread release of IL-1, IL-6 and TNF-alpha
- Presentation: Bacteremia and septic shock
Which nerve roots is responsible for perianal anesthesia?
- S2-S4, aka saddle anesthesia
What plays an important role in mRNA translation and mRNA degradation?
Cytoplasmic P bodies
Describe the effects of Phenylephrine:
- alpha 1
- BP: Increase
- HR: decrease
Describe Hep B marker: HBsAg
- Hep B virus surface glycoproteins
- Detectable during acute infection
- Persistence >6 mo = chronic infection
What would you expect with UV radiation damage?
Endonuclease nicking of the damaged DNA => Xeroderma pigmentosum
If the rectus abdomens muscle is incised laterally, what structure is at greater risk of injury?
Inferior epigastric artery
Describe the Hep B marker: HBeAg
- Hep B virus polypeptide
- Detectable during acute infection
- Indicates increase replication and infectivity
GI Pathology:
Elevated unconjugated bilirubin, intermittent scleral icterus, normal PE and vitals. What is Dx?
Gilbert Syndrome. Icterus upon a stressor.
Pathophysiology: Dec. activity of UDP Glucoronosyltransferase
The presence of a central vascular catheter and receipt of parenteral are risk factors for what?
Candida in the blood -> candademia
*Pseudohyphae with blastoconidia
Where is type 3 collagen found, and what is its association?
Location: Skin, lungs, intestines, blood vessels, bone marrow, lymphatics, and granulation tissue.
Associated with Vascular Ehlers-Danlos Syndrome type 4
Where is type 4 collagen found, and what is its association?
Location: Found in basement membrane
Associated with Alport Syndrome
Cannulation above the inguinal ligament can significantly increase the risk for what?
Retroperitoneal Hemorrhage
Lesion where in the brain would cause contralateral sensory deficits and cortical sensory signs?
The somatosensory cortex, located posterior to the central sulcus
Describe Persistent Vitelline Duct:
- Complete duct closure failure
- Results in a patient connection between intestinal line and the umbilicus.
- Causes meconium discharge from the umbilicus after birth
Describe Exudative Pleural Effusion:
Light Criteria:
- Pleural protein/serum protein > 0.5, or
- Pleural LDH/ serum LDH >0.6, or
- Pleural LDH >2/3 upper limit of normal
Pathophysiology: Inflammation increase in membrane permeability
Common Cause:
- Infection (eg, pneumonia, TB), malignancy, Rheumatologic disease
Describe Small Cell Carcinoma of the Lung:
Clinical features:
- Risks: Smoking, male> female. Highly aggressive, centrally located.
- Histology: sheets of small blue cells with scant cytoplasm.
- Neuroendocrine markers: neural cell adhesion molecule (NCAM), neuron-specific enolase, chromogranin, synaptophysin.
Associated Paraneoplastic Syndromes:
- SIADH
- Cushing Syndrome
- Lambert-Eaton Syndrome
Describe the Hep B marker: Anti-HBc IgG
Present in both acute and chronic infection. Not present after vaccination.
What is responsible for vaccine reactogenicity?
Macrophages and IL-6, and Mast cells and IL-1. Look for warmth, swelling, edema, fatigue. fever, and headache.
Gram negative bacilli, fast lactose fermenter, indole negative:
Klebsiella, Enterobacter
What would be contained in Meckel Diverticulum?
Heterotopic/Ectopic Gastric Mucosa
What nerve is in close proximity to the crust terminals of the right atrium?
Right Phrenic nerve -> elevation of right hemidiaphragm
Which cytokines are responsible for cachexia?
TNF-alpha, IL-1 beta, IL-6
Cardiovascular Pathology:
In Mitral Stenosis, how do the Left ventricular hemodynamics look during rest?
Normal Diastolic pressure, after load, and contractility
What nerve is responsible for adducting the thigh?
Obturator Nerve
Describe the effects of Dobutamine:
Beta 1 > Beta 2 receptor binding.
BP: -/decrease
HR: Increase
What are the complication of Hereditary Spherocytosis?
Pigmented gallstones, Aplastic crisis with Parvovirus B19 infection
Describe the effects of Isoproterenol:
Beta 1 = Beta 2 receptor binding
BP: -/decrease
HR: increase
Describe the 1st line Tx for Schizophrenia:
D2 receptor antagonists- antipsycotics
Where would suspect an ectopic foci in a patient with AFib?
Pulmonary Veins
List the key features for congenital Cytomegalovirus?
- Periventricular calcifications
- Microcephaly
- Sensorineural hearing loss
What is the effect of surfactant on Functional Residual Capacity?
Increase
What is released from mast cells and basophils during anaphylaxis?
Histamine and Tryptase respectively
Describe Hep B marker: Anti-HBs
Seen with cleared infection or vaccination. Confers long-term immunity
Which drugs inhibit ADP mediated platelet aggregation. Useful in PCI, tx in unstable angina, and non-Q wave MI?
Ticlodipine and Clopidogrel
What is deficient and what is accumulated in Tay-Sacks Disease?
Deficient in Beta-hexosamidase A
Accumulates GM2 ganglioside
Gram negative diplococci, aerobic, can utilize maltose?
N. Meningitidis
Which host factors are primarily responsible for mediating the response to Trastazumab?
Natural Killer cells and granzymes
Withdrawal of what substance causes anxiety, tremor, insomnia, and sympathetic hyperactivity (eg, diaphoresis, palpitations). Severe cases cause psychosis, seizures, and death?
Benzodiazepines eg, Lorazepam
What causes nonpitting edema in neonates with Turner Syndrome?
Lymphatic network dysgenesis
What causes cleft palate?
Palatine shelves fail to fuse
Describe Cryptosporidium parvum:
Pathogenesis:
- A parasite spread via fecal-oral transmission (eg, contaminated water, animal contact)
- Oocyte ingestion -> sporozoite attachment to intestinal epithelium -> intraluminal merino formation -> fecal oocyte shedding.
Clinical manifestations:
- immunocompetent: self-resolving, watery (noninflammatory) diarrhea < 2 weeks
- Immunosuppressed (eg, AIDS, transplant recipient): prolonged, severe diarrhea with weight loss/ malabsorption.
Dx:
- Stool PCR testing
- Stool microscopy: acid-fast staining oocytes or immunofluorescent assay.
Histology:
- basophilic Cryptosporidium organisms on intestinal brush border, small intestine villous blunting, lamina propria inflammation
What organism has a narrow zone of clear hemolysis with zone enhancement in the presence of Staph. Aureus?
Streptococcus agalactiae (GBS)
Describe a Glomangioma:
A benign tumor of the modified smooth muscle cells of a glomus body. Glomus bodies are numerous small, encapsulated neuromuscular organs found in the dermis of the nail bed, pads of the fingers and toes, and the ears. Rich vasculature shunts blood away as a form of thermoregulation.
Describe Pertussis:
Pathophysiology:
- Bordetella pertussis (gram-negative coccobacilli)
- Major virulence factors: pertussis toxin (AB toxin), adenylate cyclase toxin, tracheal cytotoxin
Clinical stages:
- Catarrhal (1-2 wks): mild cough, rhinitis
- Paroxysmal (2-6 wks): severe coughing spells with inspiratory whoop, posttussive emesis; w/ w/o apnea/cyanosis (infants)
- Convalescent (weeks to months): gradual resolution
Treatment:
- Macrolide antibiotic (eg, azithromycin) (50S, inhibits protein synthesis)
- Prevention: Acellular pertussis vaccine.
Describe the 6 Pharyngeal and Aortic arches with associations:
- Trigeminal (CN V), Maxillary artery
- Facial (CN VII), Stapedial artery (regresses)
- Glossopharyngeal (CN IX), Common carotid artery and proximal internal carotid artery.
- Superior laryngeal branch of vagus ( CN X), True aortic arch, subclavian arteries.
- Obliterated
- Recurrent laryngeal branch of CN X, Pulmonary arteries, ductus arteriosus
Describe the step involved in Base excision repair:
- Glycosylase: Cleaves the altered base, leaving an AP site
- Endonuclease: cleaves the 5’ end
- Lyase: Cleaves the 3’ sugar phosphate
- Polymerase: Fills the single nucleotide gap
- Ligase: Seals the nick
What you expect to decrease in Wernicke encephalopathy?
Erythrocyte transketolase activity