Random Flashcards
What are the major toxicities of acyclovir?
crystal nephropathy and neurotoxicity
What are the major toxicities of Cidofovir (CMV retinitis)?
nephrotoxicity–> proteinuria or increased creatinine
What are the major toxicities of lamivudine?
peripheral neuropathy, lactic acidosis
What are the major toxicities of sofosbuvir?
fatigue, nausea
What are the major toxicities of gancyclovir?
severe neutropenia
Where is ribosomal RNA transcribed?
The nucleolus
Which vitamins are deficient in breast milk?
Vitamin D & K
What is defective in xeroderma pigmentosum?
Nucleotide excision repair- thymine dimers repaired by UV specific endonuclease
What symptoms are seen in vitamin A deficiency?
night blindness, corneal ulceration and severe eye dryness, hyperkeratosis, growth retardation
What does secretin stimulate?
release of bicarb from pancreatic ductal cells
What is the form of dendritic cell most commonly found in the skin and mucous membranes?
Langerhans cell- racquet-shaped, derived from the myeloid cell line
Which geniculate body is auditory and which is visual?
Lateral: visual
Medial: auditory
What are the steps in base excision repair?
- recognition of abnormal bases by glycosylases, which cleave the base, leaving an empty site
- Endonuclease cleaves the 5’ site
- Lyase completes extraction
- DNA Polymerase fills in
- Ligase seals the final nick
What mediates DIC in pregnancy?
tissue factor released from sites of placental injury, initiating the clotting cascade. Most commonly caused by a placental abruption that leads to fetal demise.
Why does hyperventilation cause neurological symptoms?
decrease in pCO2 causes a decrease in cerebral blood flow, because CO2 is a potent vasodilator
Which cephalosporins have action against Pseudomonas?
Ceftazidime, cefepime
What virulence factor does Staph A have in its cell wall?
Protein A- binds the Fc portion of IgG and prevents complement binding, leading to impaired opsonization and phagocytosis.
How do you differentiate roseola from measles/rubella?
Roseola has high fever or 3-5 that goes away before the rash. The rash starts on the trunk then spreads, whereas with rubella/measles it starts on the face then spreads
What is a complication associated with APML?
DIC
What is the most common location of anterior nosebleeds?
Nasal septum- Kiesselbach plexus (anastamosis of anterior ethmoidal a, sphenopalatine a, and superior labial a.
What is the treatment for 21-hydroxylase deficiency?
physiologic doses of exogenous corticosteroids
Where are bile acids normally reabsorbed?
Terminal ileum- resection can lead to wasting of bile acids and poor absorption of fat and Vitamins ADEK
What are the teratogenic effects of ACEi and ARBs?
Low Ang II leads to renal maldevelopment and oligohydramnios, leading to pulm hypoplasia and skeletal defects
What are the teratogenic effects of tobacco?
impaired O2 delivery leads to growth restriction and preterm labor
What are the symptoms of polymyositis? Pathologic features?
Proximal muscle weakness
endomysial mononuclear infiltrate with patchy necrosis
Anti-Jo-1
Over-expression of MHC I on sarcolemma, leading to CD8 myocyte damage
How do Cyclosporine and Tacrolimus inhibit T-cells?
Inhibit calcineurin activation
normally, calcineurin–>NFAT–>IL-2–>growth and differentiation of T-cells
What is crest syndrome?
Calcinosis Raynaud's Esophageal dysmotility Sclerodactyly Telangiectasias
What should be supplemented in a pt with orotic aciduria?
Uridine
What are the symptoms of orotic aciduria?
physical and mental retardation, megaloblastic anemia, and elevated urinary orotic acid
Where in the cell is collagen synthesized?
Rough endoplasmic reticulum
How is Vit C involved in collagen synthesis?
required cofactor for hydroxylation of collagen alpha chain proline and lysine in the RER
Where do type B aortic dissections usually arise?
Close to the origin of the left subclavian artery
Where do type A aortic dissections usually arise?
in the sinotubular junction
How do nitrites cause poisoning?
Oxidize Fe2+ to Fe3+ –> formation of methemoglobin that cannot bind O2. Also, allosteric effects such that affinity of the other Hgbs in the tetramer is increased, shifting the dissociation curve to the left
How is oral bioavailability determined?
area under the oral curve divided by area under the ive curve (graph of plasma concentration over time)
How does prostate cancer to the lumbrosacral spine?
via the vertebral venous plexus, which communicates with the prostatic venous plexus (prostate, penis, and bladder). This can also lead to brain metastases, because it runs straight to the brain
What is the most frequent cause of malignant otitis externa?
Pseudomonas
How are particles in the respiratory bronchioles and alveolar ducts cleared?
Macrophages- This leads to release of cytokines, platelet-derived GF, and insulin-like GF –> stimulate fibroblasts–>progressive interstitial lung fibrosis
Which lung cancer causes SIADH? What are the tumor cell markers?
Small cell lung cancer
Neuroendocrine markers: Neural cell adhesion molecule, neuron-specific enolase, chromogranin, and synaptophysin.
What is the most common cause of death in TCA overdose? Why?
Cardiac arrhythmia- TCAs inhibit fast sodium channel conduction, leading to slow myocardial depolarization. Can also lead to refractory hypotension and peripheral vasodilation (alpha 1 adrenergic receptor antagonism)
What are the first line treatments or bipolar disorder?
Valproate, Quetiapine, and lithium
Which enzyme is absent in criggler najjar and which step of bilirubin conjugation does this disrupt?
UGT (uridine diphosphate glucuronyltransferase), which conjugates bilirubin with glucuronic acid.
What is kernicterus?
bilirubin encephalopathy- potentially fatal, severe jaundice, neurologic impairment
What determines the ventricular contraction rate in atrial fibrillation?
AV node refractory period
What is the difference between junctional, compound, and intradermal nevi?
junctional nevi- limited to the dermoepidermal junction. Flat pigmented macules
compound nevi- nevus extends into dermis. Raised papules
Intradermal- older. lost the epidermal nests. skin to tan colored dome-shaped
What is a serious complication of untreated IBD? How should it be diagnosed?
Toxic Megacolon
Abdominal x-ray
What are the symptoms of toxic megacolon?
ab pain/distention, fever, bloody diarrhea, signs of shock
What causes gallstones in pts with TPN?
Decreased cholecystokinin release due to lack of enteral stimulation leads to reduced biliary contraction and biliary stasis.
Where are parietal cells located and what do they secrete?
upper glandular layer of the gastric body and fundus.
They secrete gastric acid and intrinsic factor
What defects would be expected in Patau syndrome?
Midline defects: holoprosencephaly, microcephaly, micropthalmia, cleft palate, omphalocele, polydactyly, and cutis aplasia
Which prokaryotic polymerase has both 3’ to 5’ and 5’ to 3’ exonuclease activity?
DNA Pol I
What are the two types of Hyperimmunoglobulin M syndrome deficiencies?
CD40L: XLR Most common
CD40: AR
What activates trypsin? Which other pancreatic enzymes does trypsin activate? Where?
Trypsinogen is activated to trypsin by enteropeptidases in the brush border of the duodenum. Trypsin then activates chymotrypsinogen, procarboxypeptidase, and proelastase.
What issues are seen in patients with enteropeptidase deficiency?
Protein and fat malabsorption –> diarrhea, failure to thrive, edema
What deficiency causes porphyria cutanea tarda?
uroporphyrinogen decarboxylase
What enzyme deficiencies result in photosensitivity?
uroporphyrinogen decarboxylase, coprophyrinogen oxidase, protoporphyrinogen oxidase, or ferrochelatase
What is the defect in lynch syndrome (hereditary nonpolyposis colon cancer)? What are the most common mutations?
Defective DNA mismatch repair
MSH (MutS) & MLH1 (MutL)
What does overlying skin retraction signal in invasive breast carcinoma?
involvement of the suspensory ligaments of the breast.
How does invasive breast carcinoma usually present?
As an irregularly shaped adherent breast mass
What causes spinal stenosis?
degenerative arthritis of the spine results in narrowing of the spinal canal due to intervertebral disc herniation, ligamentum flavum hypertorphy, and osteophyte formation
What are the symptoms of spinal stenosis?
posture-dependent lower extremity pain, numbness/paresthesia, and weakness. Worse with standing up, better with leaning or walking uphill
What topical drug used for psoriasis activates Vitamin D receptors? Why is that therapeutic?
Vit D analogs- calcipotriol, calcitriol, and tacalcitol
Vit D receptor is a nuclear transcription factor that causes inhibition of keratinocyte proliferation and stimulation of keratinocyte differentiation
What are the symptoms associated with dengue fever? Dengue hemorrhagic fever?
flu-like febrile illness with MARKED MYALGIAS and JOINT PAIN, retro-orbital pain, rash
Hemorrhagic: thrombocytopenia, spontaneous bleeding- shock
What causes dengue hemorrhagic fever?
Exposure to a different serotype after primary exposure. May be due to Ab dependent enhancement of infection, enhanced immune complex formation, and/or accelerated Tcell response
What organs are most commonly affected by GVHD? What are the symptoms?
Skin, liver, GI
Usually starts with maculopapular rash on the soles and palms
Abnormal LFTs
diarrhea, intestinal bleeding, ab pain
Which bacteria are most commonly involved in cholecystitis?
E Coli, Enterococcus, Klebsiella, Enterobacter
What illnesses does the H flu vaccine protect against?
H flu type b- MENINGITIS, pneumonia, epiglottitis, and sepsis
What are the signs associated with hypocalcemia?
Chvostek: muscle contraction elicited by tapping on the facial nerve.
Trousseau: Carpopedal spasm with polonged inflation of a blood pressure cuff around the arm
What is the most common cause of hypocalcemia?
injury to the parathyroids during thyroid surgery
What does rituximab target?
monoclonal Ab against the CD 20 surface Ig on B cells (lymphoma)
What does Infliximab target?
chimeric IgG1 against TNF-alpha (RA, Ankylosing spondylitis, fistulizing Crohn’s)
Why is IL-2 used for treatment of renal cell carcinoma and melanoma?
It regulates activation and differentiation of t cells to aid in tumor destruction
What test can be used to diagnose strep pyogenes?
Pyrrolidonyl arylamidase test (PYR +)
Which malignancies cause osteoblastic (sclerotic) cancers?
More indolent
Prostate cancer
small cell lung
Hodkin lymphoma
Which malignancies cause osteolytic (lucent) cancers?
Aggressive Multiple myelome non-small cell lung non-Hodgkin lymphoma renal cell carcinoma melanoma
Which malignancies cause mixed osteolytic and osteoblastic cancers?
GI
Breast
Why are nitrates dosed to have a long gap overnight?
Nitrate-free interval is to prevent tolerance
What is a very bad long term risk associated with PCOS? Why?
Endometrial carcinoma- imbalance of estrogen and progesterone, because there isn’t a monthly dominant follicle to produce progesterone
What proteins are involved in gap junctions?
Connexins
What proteins are involved in Tight Junctions?
Claudins, occludin
What proteins are involved in Adherens junctions?
cadherin
What proteins are involved in Desmosomes?
Cadherins (desmogleins, desmoplakin)
What proteins are involved in Hemidesmosomes?
Integrins
What are the derivative of the 3rd branchial pouch?
dorsal: inferior parathyroids
ventral: thymus
What are the derivative of the 1st branchial pouch?
Middle ear cavity, eustachian tube, mastoid air cells
What are the derivative of the 2nd branchial pouch?
Epithelial lining of the palatine tonsil
What are the derivative of the 4th branchial pouch?
Dorsal: superior parathyroid
Ventral: ultimobranchial body and Thyroid parafollicular (C) cells
What hormone causes increase in insulin resistance during pregnancy?
human placental lactogen
Why do high levels of aflatoxin cause hepatocellular carcinoma?
G:C –> T:A transversion in codon 249 of the p53 gene
In third degree heart block, what is responsible for ventricular pacing?
AV nodal cells
What nerve provides innervation to the suprapubic region?
iliohypogastric
What nerve provides sensory innervation to the upper thigh and inner leg and motor innervation to muscles that extend the knee?
femoral
What nerve provides sensory innervation to the upper anterior thigh and motor innervation to parts of the genitalia?
genitofemoral
What nerve provides sensory innervation to the upper and medial thigh and parts of the external genitalia?
ilioinguinal
What nerve provides sensory innervation to the lateral thigh
Lateral femoral cutaneous
What nerve provides sensory innervation to the medial thigh and motor innervation to the adductor muscles of the lower extremity?
Obturator nerve
What are the signs and symptoms of gallstone ileus? What causes it?
Bowel obstruction with ab pain/distention, N/V, there may be gas in the gallbladder and biliary tree
A large gallstone causes formation of a cholecystenteric fistula b/w gallbladder and small intestine. Gallstone travels freely until it gets stuck in the ileum
What are amatoxins? where are they found? what do they do? What are the symptoms?
Amatoxins are in poisonous mushrooms and get concentrated in the liver where they bind DNA-dependent RNA pol II and halt mRNA synthesis, ultimately resulting in apoptosis
Symptoms: ab pain, vomiting, sever, cholera-like diarrhea- can lead to acute hepatic and renal failure
NAD+ is necessary for which step of the TCA cycle? How does it get converted back from NADH in aerobic and anaerobic conditions?
Necessary for G3P–>1,3 BPG
Aerobic: during TCA cycle
Anaerobic: Conversion of pyruvate to lactate by lactate dehydrogenase
Without recovery of NADH, glycolysis cannot continue
How can GI bleeding lead to hepatic encephalopathy?
Bleeding in the gut leads to breakdown of Hgb, which produces ammonia that is absorbed into the blood stream. If the patient has impaired liver function, they will not be able to detoxify this ammonia to urea
What are the 3 causes of HIV-associated esophagitis and what are the endoscopic findings?
Candida Albicans: patches of adherent, grey/white pseudomembranes on erythematous mucosa
HSV-1: Small vesicles–> punched out ulcers
CMV: Linear ulcerations
What artery provides blood supply to the pelvic organs and should ligated during postpartum hemorrhage? Is the patient infertile after this procedure?
Internal iliac arteries
No, because there is collateral blood supply to the uterus from the ovarian arteries
What is the mechanism of resistance to aminoglycosides?
Bacterial production of aminoglycoside modifying enzymes
Acquired from transposon or plasmid
Which adrenoreceptors are activated by norepi?
Alpha 1&2, and Beta 1
NOT Beta 2 (No bronchodilation or vasodilation)
What usually causes hepatic abscess in developed countries? Undeveloped countries?
developed countries: Bacterial infection (Staph A)- Can gain access via biliary tract infection, portal vein pyemia, hepatic artery, Direct invasion from adjacent source, or penetrating trauma
Undeveloped countries: Parasitic infection (Entamoeba histolytica, echinoccocal)
What is the most common cause of bloody nipple discharge?
intraductal papilloma- proliferation o papillary cells in a duct or cyst with fibrovascular core
How can rasburicase help to prevent tumor lysis syndrome?
Rasburicase is a recombinant version of urate oxidase, which converts uric acid into allontoin. Allantoin is 5-10x more soluble in urine than uric acid
Describethe gram stain and media used to grow cholera
oxidase +, gram -, comma-shaped organism that grows on high-alkaline selective media
Which diarrheal bacteria causes fecal mononuclear leukocytes?
Salmonella Typhi
What is the main source of protection from reinfection with a similar strain of flu virus?
antibodies to hemagglutinin
What cell is important for prevention of superficial candida infection? Hematogenous spread?
superficial candida infection: T-cells
Hematogenous spread: Neutrophils
What are the dysmorphic features associated with Edwards (trisomy 18) syndrome?
micrognathia, low-set ears, prominent occiput, hypertonia, clenched fists with overlapping fingers, Cardiac, genitourinary, and GI anomalies
Where are aspiration pneumonias in supine individuals?
dependent locations:
Superior regions of the lower lobe and posterior regions of the upper lobes
What are the complications that can occur with congenital CMV infection?
chorioretinitis, sensorineural deafness, seizures, jaundice, hepatomegaly, splenomegaly, and microcephaly
Which branch of the trigeminal nerve controls the muscles of mastication?
Mandibular
Which cells produce IFN-gamma? What does it do
Produced by activated Tcells and NK cells in response to IL-12 from macrophages, IFN-gamma stimulates macrophages to kill phagocytosed pathogens
How do interferon gamma release assays test for TB?
Measure response of Tcells when exposed to TB antigens
Which familial cancer genes are associated with pheochromocytoma?
VHL, RET (MEN2), NF1
Form which cells does a pheochromocytoma arise?
The chromaffin cells of the adrenal medulla
How many half-lives does it take to reach steady state of a drug?
4-5
What cardiac issue associated with a murmur can cause head bobbing and nocturnal palpitations?
Aortic regurgitation:
head bobbing from widened pulse pressure
nocturnal palpitations from forceful ventricular contractions ejecting large stroke volumes
What is the effect of sun exposure on vitamin D?
Converts 7-dehydrocholesterol (provitamin D3) to cholecalciferol (D3)
What is the pathogenesis of preeclampsia?
abnormal placental vasculature–> hypoxic placenta–> release of antiangiogenic factors–> endothelial injury–> increased permeability (proteinuria) and dysregulation of vascular tone (hypertension)
What is Rett syndrome?
X-linked de novo mutation in the MECP2 gene
Normal development until 5-18 months followed by a loss of motor and language skills, stereotypic hand movements, deceleration of head growth, seizures, ID
What is adenomyosis and how does it present?
Presence of endometrial glandular tissue in the myometrium, usually in middle-aged parous females
Presents with heavy menstrual bleeding, dysmenorrhea, and uniformly enlarged uterus
What is the most common congenital anomaly of the small intestine?
Meckel diverticulum due to incomplete obliteration of the omphalomesenteric duct that connects the midgut lumen and yolk sac cavity (rule of 2s). Can contain ectopic tissue- most often gastric epithelium producing acid that ulcerates neighboring tissue and causes painless melena
What are the pathologic findings in Primary Biliary cirrhosis and graft versus host disease?
lymphocytic inflammation with destruction of intrahepatic bile ducts
What are the pathologic findings in serious acetaminophen overdose?
liver failure with centrilobular necrosis that can extend to the entire lobe
What are the pathologic findings in Alcoholic hepatitis?
hepatocellular swelling and necrosis, mallory bodies, neutrophilic infiltration, and fibrosis
What are the pathologic findings in Budd-Chiari syndrome?
Clot at the junction of hepatic vein and IVC causes increased intrahepatic pressure–> reddish-purple parenchyma with severe centrilobular congestion and necrosis
What are the adverse effects associated with erythropoiesis-stimulating agents?
thromboembolic events, hypertension
What are the primary effector cells in urushiol-induced contact dermatitis?
CD8 cells
Why do fibrates lead to gallstones?
In addition to upregulating PPAR alpha, they inhibit cholesterol 7 alpha hydroxylase, which catalyzes the last step in bile acid formation. The reduced bile acid production results in decreased cholesterol solubility.
What are the 5 cofactors required for Branched chain alpha ketoacid dehydrogenase (Deficient in MSUD)?
Thiamine, Lipoate, Coenzyme A, FAD, NAD
High dose thiamine can help improve MSUD
If a patient has been stabbed and bleeding does not stop with Pringle maneuver (occlusion of the hepatoduodenal ligament- portal triad), which vessel is likely injured?
Inferior vena cava or hepatic veins
What are the two primary sources of alkaline secretions to the duodenum?
Brunner glands
Epithelial cells of the pancreatic ductules and ducts produce water secretions containing high concentrates of bicarbonate ions
When do patients exhibit Cheyne-Stokes breathing?
Advanced congestive heart failure
Which organisms are resistant to cephalosporin?
Resistant PBPs: -Listeria -MRSA -Enterococci No cell wall -Atypicals (mycoplasma, chlamydia)
What monoclonal antibody is used in the management of HER2 positive breast cancer?
Trastuzumab- binds HER2 and prevents activation of a transmembrane tyrosine kinase
What is chlordiazepoxide?
a benzo
Which bacteria are found in soil and able to survive high temp, dessication, and chemical agents by forming spores?
Members of the Bacillus and Clostridium genuses
Why are E6 and E7 viral proteins oncogenic?
E6 binds p53, leading to ubiquitination–> can’t halt cell cycle
E7 binds Rb and displaces bound transcription factors, promoting unregulated DNA replication and cylcin-mediated cell cycling
Why do patients with normal pressure hydrocephalus have urinary incontinence?
Cortical fibers that run in the periventricular pathways get distended, leading to disruption of impulses from the cortex to the sacral micturition center
Which HLA allele is associated with Ankylosing spondylitis?
HLA B27
How does copper move through the body?
60% of ingested Cu is absorbed in the stomach and duodenum. It is made into ceruloplasmin in the liver, which is secreted into the plasma. Senescent ceruloplasmin and the unabsorbed Cu (40%) are secreted into bile and excreted in stool. About 5-15% of daily Cu excretion is from the kidney
What is the gram stain for H. Flu? What factors does it need to grow?
X factor (hematin) and V factor (NAD+)
What are some examples of disorders with multifactorial inheritance?
Spina Bifida, cleft lip and palate, DM, coronary artery disease, and HTN
Why do corticosteroids acutely increase the neutrophil count?
Demargination of neutrophils previously attached to the vessel wall
What will an mutation that Increases the amount of PRPP synthetase cause?
Gout, because there will be increased purine and pyrimidine production, leading to increased degradation and hyperuricemia
What are the primary cells responsible for the intense inflammatory response seen in patients with gout?
Neutrophils
What artery provides blood supply to the proximal ureter?
Renal artery
What artery provides blood supply to the distal ureter? Middle ureter?
Superior vesical artery.
Circulation to the middle ureter is anastomotic and variable
What are the symptoms of cat scratch fever? What is the presentation of Bartonella henselae in immunocompromised patients?
primary erythematous lesion followed by tender regional lymphadenopathy
Bacilliary Angiomatosis- red-purple papular skin lesions that may also be found within the viscera. Can be fatal if left untreated.
What are the parts of LPS? Which part causes sepsis?
O antigen, core polysaccharide, and lipid A
Lipid A induces shock by activation of macrophages and granulocytes
Where does lymph from the testes drain to?
para-aortic lymph nodes
What is the most common cause of fatal sporadic encephalitis?
HSV 1
What is the most common cause of bronchiolitis? In what age group does it occur?
RSV
less than 2 y/o
Which benzos can be given for anxiety without causing daytime sleepiness?
Short-acting: triazolam, oxazepam, midazolam
Intermediate-acting: lorazepam, alprazolam
From which amino acid is nitric oxide synthesized? What is the enzyme?
Arginine (+NADPH and O2)
eNOS (epithelial nitric oxide synthase)
How does NO cause vasodilation?
Activates Guanylyl cyclase–> increased cGMP, which activates protein kinase G and leads to a reduction in cytosolic Ca level
How does testosterone cause acne?
promotes follicular epidermal hyperproliferation and excessive sebum production
What do oxalate crystals in the renal tubules suggest?
Ethylene glycol poisoning causing toxic renal injury and acute tubular necrosis
What is the renal morphology on light microscopy in ethylene glycol poisoning?
Normal glomeruli, but proximal tubular necrosis with cell ballooning and vacuolar degeneration
What is the most common secondary tumor in patients with hereditary retinoblastoma?
Osteosarcoma,
They also are at high risk for other types of sarcoma
What is the action of the Rb gene on chromosome 13?
Tumor suppressor, active when dephosphorylated, does not allow cell to proceed from G1 to S
Phosphorylation of Rb permits cell division
Which patients are at higher risk of developing ALL?
Down Syndrome, Ataxia Telangiectasia, and NF1
What are the risks to children of secondhand smoke?
Prematurity, low birth weight SIDS Middle ear disease Asthma Respiratory tract infections
What is the most common benign tumor in the lung?
hamartoma: well-defined coin lesion with “popcorn calcifications”
What are the epithelia associated with: ovary, fallopian tube, uterus, cervix, and vagina?
ovary: Simple cuboidal
fallopian tube: Simple columnar- ciliated cells transport egg/embryo
uterus: Simple columnar- prolonged estrogen prevents shedding–> hyperplasia/malignancy
Endocervix: Simple columnar
Ectocervix: Stratified squamous non-keratinized
vagina: Stratified squamous non-keratinized- maintains acidic environment
What are the symptoms of primary carnitine deficiency?
myopathy, cardiomyopathy, hypoketotic hypoglycemia, decreased muscle carnitine content
Why s carnitine necessary?
Needed to shuttle fatty acids from the cytoplasm into the mitochondria during fatty acid oxidation. Therefore muscles can’t use fats for ATP generation, and liver can’t synthesize ketone bodies (acetoacetate) when glucose levels are low
What causes X linked agammaglobulinemia?
Failure of bone marrow pre-B cells to mature, leading to low or absent B cell levels and pan hypoglobulinemia
What causes sarcoidosis?
dyregulated cell-mediated immune response to unknown antigen driven by macrophages and Th1: IL-2 and IFN-gamma. Promote formation of non-caseating granulomas
Which hormone is responsible for gallbladder contraction? Where is it made?
Cholecystokinin- made in duodenum and jejunum in response to fatty acids and amino acids
What does RT-PCR detect and measure?
mRNA (produce complementary cDNA with the exons nad 5’ and 3’ untranslated regions)
What causes brown pigmented stones?
Typically arise secondary to bacterial or helminthic infections that result in the release of beta-glucuronidase from injured hepatocytes and bacteria. The beta-glucuronidase hydrolyzes bilirubin glucuronides and leads to increased unconjugated bilirubin
What are the pathological findings in HPV?
Koilocytes- immature squamous cell with dense, irregularly staining cytoplasm and perinuclear clearing, resulting in a halo. “raisinoid” appearance of the the enlarged pyknotic nucleus
Which nerve supplies innervation to the perineum?
Pudendal
Which nerve supplies sympathetic and parasympathetic innervation to the internal pelvic viscera?
inferior hypogastric plexus
Which nerve supplies parasympathetic (only) innervation to the pelvic and genital organs?
Pelvic splanchnic nerve (S2-4)
What does the inferior gluteal nerve supply?
Motor function to the gluteus maximus
What test should be used to check for fat malabsorption?
Sudan III stain of the the stool to check for fat
What is the appearance of the liver on autopsy in Inhaled anesthetic hepatotoxicity? What anesthetic is most commonly associated?
Shrunken due to rapid atrophy with widespread centrilobular necrosis and inflammation to the portal tracts and parenchyma (same as fulminant hepatitis)
Halothane, but also enflurane, isoflurane, desflurane, and sevoflurane
What are the symptoms and lab findings in inhaled anesthetic hepatotoxicity?
fever, anorexia, nausea, myalgia, tender hepatomegaly, and jaundice
Elevated LFTs, Prolonged PT, leukocytosis, and eosinophilia
What are the symptoms of meniere’s disease?
low frequency tinnitus with a feeling of fullness
Vertigo
Sensorineural hearing loss
What causes meniere’s disease?
Defective resorption of endolymph and resultant increase in volume and pressure of endolymph, causing damage to the vestibular and cochlear components of the inner ear
What is the primary pathophysiologic mechanism responsible for GERD?
Gastroesophageal junction incompetence
What are characteristic histological findings in GERD?
Distal esophagus with basal zone hyperplasia, elongation of the lamina propria papillae, and scattered eosinophils and neutrophils
What happens when a muscle contracts too hard?
It pulls the golgi tendon organ, which uses 1b sensory axons to contact inhibitory interneurons that synapse with the alpha motor neurons from that group–> relaxation
What happens when a muscle is stretched?
Activates the intrafusal fibers of the muscle spindle, leading to contraction–> deep tendon reflex
How do shiga and shiga-like toxins work?
inactivate 60s ribosomal subunit in human cells
What are some common medical conditions with polygenic inheritance?
androgenetic alopecia epilepsy glaucoma HTN Ischemic hrt dz schizophrenia T2DM
Describe the findings in hirschsprung disease
fail to pass meconium within 48 hours
bilious vomiting, ab distention
empty rectal vault
increased anal sphincter tone
What can be used to treat lyme disease?
doxycycline
penicillin-type antibodies (ceftriaxone)
Why is HbA1C falsely low in people with beta thalassemia?
High RBC turnover rate means there is a shorter period of exposure to high glucose levels
Look for elevated HbA2 to diagnose beta thalassemia
What is the exotoxin involved in staph scalded skin syndrome? How does it present?
Exfoliatin- cleaves desmoglein in desmosomes (only in epidermis)
Skin slips off with gentle pressure, epidermal necrolysis, fever, and pain
(bullous impetigo is a more localized form of SSSS)
What type of epithelium is HPV most likely to infect? Where is it located?
Stratified squamous epithelium
anal canal, vagina, cervix, and the true vocal cords in the respiratory tract
What conditions are associated with osteonecrosis of the femoral head?
Sickle cell dz–> thrombotic occlusion
Vasculitis–> impaired blood supply
Corticosteroids and alcohol–> unknown mechanism
What are the s/s associated with glucagonoma (rare tumor of the alpha cells of the pancreatic islets of Langerhans)?
DM
Necrolytic migratory erythema: Erythematous papules/plaques on face, perineum, extremities. The lesions enlarge and coalesce, leaving a bronze-colored, central indurated area with peripheral blisters and scaling
What is the order of fastest to slowest conduction in the heart?
Purkinje>Atrial>Ventricular>AV node
Which Biochemical processes take place in the cytosol?
glycolysis, fatty acid synthesis, and the pentose phosphate pathway
Which Biochemical processes take place in the mitochondria?
beta-oxidation of fatty acids, TCA cycle, and carboxylation of pyruvate
What does hormone sensitive lipase do and where is it found?
Stress hormone induces release of hormone sensitive lipase in adipose tissue, which catalyzaes the mobilization of TGs into FFAs and glycerol.
Glycerol is a source of Cs for gluconeogenesis and FAs are used to make Acetyl CoA for the TCA cycle or further metabolized into ketone bodies
What structure is most vulnerable to injury during a hysterectomy?
Ureter, because it is just deep to the where the uterine vessels are ligated and the closure of the lateral aspect of the vaginal cuff–> can be sutured shut by accident
What is the most common GI abnormality associated with Down Syndrome? How does it present?
Duodenal atresia (failure of the recanalization of the duodenum in early gestation)
Double bubble sign and bilious emesis
Other GI issues: imperforate anus, Hirschsprung dz, TE fistula, and celiac dz
What is Buspirone used to treat? How?
Generalized anxiety disorder
partial agonist of the 5HT1A receptor
Slow onset of action
What is the difference between the ulcers in HSV, Haemophilus ducreyi, Klebsiella granulomatis, and chlamydia trachomatis?
HSV: shallow ulcerations with erythematous base Haemophilus ducreyi (chancroid): deep, purulent, painful ulcers with suppurative lymphadenitis Klebsiella granulomatis (granuloma inguinale): painless, progressive, red serpiginous ulcerative lesions without lymphadenopathy Chlamydia trachomatis (lymphogranuloma venereum): Initially painless small and shallow ulcers, followed by large painful coalesced lymph nodes, intracytoplasmic chlamydial inclusion bodies in epithelia cells and leukocytes
What causes uncomplicated umbilical hernia?
incomplete closure of the umbilical ring–> linea alba not formed. Most resolve spontaneously. Associated with Downs, Hypothyroidism, and Beckwith-Wiedemann syndrome
What are the most common microbes involved in nec fasc?
S. Pyogenes, S. Aureus, C. perfringens, and polymicrobial
What are the major virulence factors involved in S. Pyogenes necrotizing fasciitis?
Hyaluronidase- spread through skin and fascia
M protein- evades phagocytosis by preventing activation of the alternative complement pathway
Hemolysins O and S- hemolysis
Pyrogenic exotoxin: superantigen–> tissue injury and septic shock
Where are lesions that cause homonymous hemianopia with macular sparing? Why is the macula spared?
Occipital cortex - posterior cerebral artery
The macula is spared because there is collateral blood flow from the middle cerebral artery to the occipital pole, which processes central visual info
What causes reactive arthritis? What does joint aspirate show?
Reactive arthritis is caused by immune complex deposition with bacterial antigens, though it is not a disseminated infection- taps are sterile. It most commonly follows infection with campylobacter, shigella, salmonella, Yersinia, CT, or Bartonella
What are the extraarticular sx associated with reactive arthritis? What is the associated HLA type?
conjunctivitis, urethritis, and keratoderma blennorrhagicum
HLA-B27
What should be monitored in a patient taking olanzapine?
BMI, fasting glucose and lipids, BP, waist circumference
What is the action of colchicine? Why is it given?
binds intracellular tubulin and inhibits its polymerization- This disrupts functions such as chemotaxis, phagocytosis, and degranulation.
Colchicine also reduces formation of LTB4
Used during gout flare when NSAIDs are contraindication
What are the pathologic features of the two types of hydatidiform mole?
Complete: diffuse trophoblastic proliferation and edematous chorionic villi (bunch of grapes)- no fetal tissue. p57-negative
Partial: Some enlarge villi with focal trophoblastic proliferation. p57-positive
Why does galactosemia cauase cataracts?
Galactokinase deficiency prevents galactose from being converted into galactose 1 phosphate. Instead, it is converted by aldose reductase into galactitol that is an osmotic agent and causes cataracts
How can Galactokinase deficiency show up in urine tests?
excess galactose spills into urine, causing it to test positive for a reducing substance
How does Galactokinase deficiency compare to deficiency of galactose-1-phosphate uridyl transferase?
GALT is much more severe due to buildup of toxic galactose-1-phosphate, which causes hepatic and renal dysfunction. It presents in neonates as vomiting, lethargy, and failure to thrive.
Where is the most common site of intussusception? How is it diagnosed and treated?
ileocecal junction
Barium enema is used for diagnosis, but can also be the treatment- if it doesn’t work, then surgery
What ratio is important for determining whether there will be increased bone turnover?
Osteoprotegerin to RANK-L
Low ratio means more bone being resorbed
How does prolonged NSAID use lead to chronic interstitial nephritis?
NSAIDs uncouple oxidative phosphorylation and deplete glutathione, leading to lipid peroxidation–> damage to tubular and vascular endothelial cells
Also leads to ischemic papillary necrosis via constriction of the medullary vasa recta
What are the pathological findings in chronic interstitial nephritis?
patchy interstitial inflammation–> fibrosis, tubular atrophy, papillary necrosis and scarring, and caliceal architecture destruction
What pathway does IFN gamma activate in macrophages?
Jak-STAT
How do you tell the difference between 21-hydroxylase deficiency and aromatase deficiency in a female newborn with clitoromegaly?
With aromatase deficiency, the mom will undergo virilization (hirsutism) during the pregnancy
Which tumor most typically metastasizes to the ovaries?
GI tumor
What is it called when gastric cancer metastasizes to the ovaries? How does it present?
Krukenberg tumor
unintentional weight loss, epigastric pain, and adnexal masses
What is the pathologic finding in gastric cancer with krukenberg tumor?
Signet ring cell- large amount of mucin displacing the nucleus
How does gastric signet ring cell cancer spread to the ovaries?
lymphatic invasion and peritoneal seeding
When would you see acute renal after initiation of ACEi?
In patients with bilateral renal artery stenosis- they depend on the vasoconstriction from Ang II to maintain GFR
Where in the nephron is urine most dilute?
Distal convoluted tubule, because solutes are still being reabsorbed, but it is relatively impermeable to water, so the water can’t be reabsorbed
What is the rate-limiting step in the synthesis of catecholamines?
Conversion of tyrosine to DOPA by tyrosine hydroxylase
What converts DOPA to dopamine?
DOPA decarboxylase
What converts dopamine to norepinephrine?
Dopamine beta-hydroxylase
What converts norepinephrine to epinephrine? Where? What upregulates expression of this enzyme?
Phenylethanolamine-N-Methyltransferase (PNMT) in the adrenal medulla. Upregulated by cortisol, so decreased cortisol/ACTH can lead to decreased conversion of Norepi to Epi
What are the three phases of paget’s disease of the bone?
- Osteolytic (osteoclast)
- Mixed Osteoclastic-Osteoblastic: abnormal bone formation with areas of disorganized lamella and woven bone
- Osteosclerotic (Osteoblast): remodeling–> dense, hypovascular mosaic pattern of lamellar bone with prominent cement lines
What are the downstream effects of Gq activation?
Alpha subunit exposes a Phospholipase C site theat hydrolyzes PIP2 into DAG and IP3. DAG stimulates PKC and IP3 releases intracellular Ca stores leading to even more PKC stimulation
How can temporomandibular disorder present? Why?
Can present with both otologic symptoms and jaw pain, because the mandibular division of CN V innervates the middle ear and the muscles of mastication
What is the blood supply to the femoral head? What can damage to it?
Medial circumflex artery
Damage from fracures of the femoral neck
How does blood from the spleen return to circulation?
Splenic vein to the portal circulation rather than going straight back to systemic circulation
What type of poisoning is caused by ingestion of pesticides? What are the symptoms?
Arsenic poisoning
ab pain, vomiting, severe watery diarrhea, delirium, and hypotension
Prolonged QTc–> Torsades de Pointes
Garlic odor on patient’s breath or stool
What damage does arsenic do when ingested? What is the treatment?
Binds sulfhydryl groups, impairing cellular respiration via inhibition of pyruvate dehydrogenase and diruption of gluconeogensis and glutathione metabolism.
Tx: Dimercaprol- chelating agent increases urinary excretion
What is a pancreatic pseudocyst? What causes it? What lines the walls of the pseudocyst?
Common complication of acute pancreatitis with collection of fluid rich in enzymes and inflammatory debris. The walls are lined by granulation tissue and fibrosis (unlike true cysts, which are lined by epithelium)
What are the most important opsonins?
C3b and IgG
mannose-binding lectin and CRP can also opsonize
With which other rheumatological disease is Giant cell arteritis associated?
Polymyalgia Rheumatica
What are the histological findings in Giant cell arteritis (temporal arteries) and Takayasu’s arteritis (aortic arch)?
scattered, focal granulomatous inflammation centered on the media with intimal thickening, elastic lamina fragmentation, and giant cell formation
What are the symptoms and histological findings in Polyarteritis Nodosa?
Sx: intermittent episodes of ab pain, peripheral neuropathy, renal insufficiency, and severe HTN
Histology: Transmural inflammation of the arterial wall with fibrinoid necrosis
What are the symptoms associated with acute HBV infection?
serum-sickness like syndrome with joint pain, lymphadenopathy, and a puriritic urticarial rash
Can also have RUQ pain, hepatomegaly, and elevated LFTs
Which organ passes between the SMA and the Aorta and is squished with a loss of mesenteric fat (low body weight, recent weight loss)?
Transverse portion of the duodenum
Why does metronidazole cause adverse reaction to alcohol?
disulfiram-like inhibition of acetaldehyde dehydrogenase causes buildup of acetaldehyde
What does tyrosinase deficiency cause?
Albinism, because tyrosinase is necessary to synthesize melanin from tyrosine
What two deficiencies can cause phenylketonuria? Which is worse?
Phenylalanine Hydroxylase
Dihydrobiopterin reductase: worse, because also can’t convert tyrosine into dopa, so can’t form NE, EPI,DA, or 5HT
What causes alcohol induced hepatic steatosis?
Decrease in fatty acid oxidation due to excess nADH production by alcohol dehydrogenase and aldehyde dehydrogenase
What is the difference between schizophrenia, brief psychotic disorder, and schizophreniform disorder?
Brief: >1 day and <1 month
Schizophreniform: >1 month and <6 months- doesn’t require functional decline
Schizophrenia: >6 months requires functional decline
What is the treatment for SCID?
Stem cell transplant
Which immune cells are responsible for type 4 hypersensitivity reaction?
Macrophages, CD4 and CD8 tcells. Macrophages present to CD4, which recruit CD8 to produce the characteristic signs of induration and edema
With which dyes does diptheria stain?
Aniline dyes (methylene blue)
What is the mutation in Hartnup disease? Why does this cause symptoms of niacin deficiency?
AR inactivating mutation of the neutral amino acid transporter in the small intestine and kidney.
This leads to tryptophan (essential a.a.) deficiency. Tryptophan is a precursor for Niacin, serotonin, and melatonin
How is hartnup disease diagnosed and treated?
Excessive neutral amino acids in urine
Treated with a high protein diet and daily niacin or nicotinamide supplementation
What is the effect of Nitrates and phosphodiesterase inhibitors on a cell?
Increased cGMP- Nitrates enhance synthesis and PDEs prevent degradation
From where to where is a midline episiotomy made?
From the posterior vaginal opening to the perineal body
What exits the skull through the jugular foramen?
CN IX, X, XI, and jugular vein
What does the uterus look like during ectopic pregnancy?
Decidualization- dilated, coiled endometrial glands and vascularized edematous stroma, prepared for implantation
NO embryonic or trophoblastic tissue