UWSA2 Flashcards
What is hydroquinone and what is it used for?
Inhibits the oxidation of tyrosine to DOPA by tyrosine hydroxylase, a key step in the synthesis of melanin in melanocytes.
-used for treatment of hyperpigmentary disorders (melasma, postinflammatory hyperpigmentation)
What are the labs for DIC?
Increased PT/PTT, D-Dimer
Decreased platelets, fibrinogen
Schistocytes present
Most salmonella species produce hydrogen sulfide except for ?
Salmonella typhi
What are the nonpolar (hydrophobic) amino acids?
Alanine, Valine, Leucine, Isoleucine, Phenylalanine, Tryptophan, Methionine, Proline, Glycine
Where do stem cells in the intestinal epithelium reside?
Crypts of Lieberkuhn
The “Dine, Bines, and Sines” except for Tenofovir and Abacavir are what drug class?
Abacavir, Tenofovir, ZalcitaBINE, EmtricitaBINE, LamivuDINE, ZidovuDINE, StavuDINE, DidanoSINE are all NRTIs**
Protein abundant in arginine and lysine. Contains 30 amino acid alpha helical segment that consists of repeated leucine residues at every seventh position. What is this
Basic-region leucine zipper class of eukaryotic Transcription Factor
Where does the midbrain and aqueduct come from
Mesencephalon
What is the first cardiac response to exercise?
Increase in heart rate, which is mediated by decreased vagal tone on the heart as well as increased sympathetic stimulation
Where do the Metencephalon and Myelencephalon come from?
Rhombencephalon
What specific part of the 30s ribosomal subunit do aminoglycosides (gentamicin) inhibit?
16S ribosomal RNA within the 30s ribosomal subunit
Transtentorial/uncal herniations fuck up what nerve
CN III
Patient is being ventilated, they are accidentally hyperventilated, which results in excessive CO2 losses and respiratory alkalosis. What will the kidneys do? What is seen in urine?
Kidneys will respond by excreting bicarbonate. Urine will be alkaline
Which enzyme catalyzes phosphorylation of glucose to G6P in pancreatic beta cells?
Glucokinase
What drugs are cytostatic drugs that inhibit mTOR, blocking the cell cycle between the G1 and S phase to reduce smooth muscle proliferation? (Used in stents)
Everolimus (coating), and drugs sirolimus, zotarolimus
From birth until menarche, the primary oocytes are quiescent and arrested in?
Arrested in prophase of meiosis 1
Why are the metaphyses of long bones usually the locations of osteomyelitis in children
Highly vascularized with relatively slow blood flow through small metaphyseal capillary loops.
What is primary ovarian insufficiency and what is the pathophysiology?
Refers to amenorrhea in women under age 40 w/ elevated gonadotropins (FSH) and low estrogen levels. Likely due to inadequate supply of ovarian follicles or a premature depletion of these follicles.
-prior chemotherapy could cause premature follicular depletion by augmenting follicular atresia, which is a process of apoptosis
What does sustained hand gip, squatting, and passive leg raise do to the murmur of hypertrophic cardiomyopathy?
Sustained hand grip: increase afterload
Squatting: Increase afterload and preload
Passive leg raise: increased preload
All lessen murmur intensity
What is imiquimod and how does it work?
Imiquimod is an imidazoquinoline nucleoside that acts as agonist of TLR 7,8 and leads to activation of NFkB.
-used as immunomodulator in the treatment of genital or perianal warts/condyloma acuminata and actinic keratosis
DeCEREbrate posturing seen in?
Pontine hemorrhages
What is the mechanism of NRTI’s?
Competitive nucleoside/nucleotide Reverse Transcriptase inhibitors—> inhibits HIV DNA synthesis from RNA template by terminating DNA chain elongation
If a patient has low bisphosphoglycerate mutase activity, what will happen to their levels of 2,3-BPG? What is the overall result of this? EPO levels?
Low 2,3-BPG resulting in increased oxygen affinity of hemoglobin. This would be a LEFT SHIFT, which hinders oxygen delivery to tissues, leading to increased erythropoietin and increased circulating red blood cell mass.
Overall, the patient’s hemoglobin will function like fetal hemoglobin which has a lower affinity for 2,3-BPG than adult hemoglobin and a curv that is shifted to the left.
What is the origin of the Pons, cerebellum, and upper 4th ventricle?
Metencephalon
What DNA polymerase is responsible for the removal of RNA primers and the synthesis of new DNA in their place?
DNA polymerase I
How does a Gq receptor work
Gq activated by ligand undergoes conformational change. Alpha subunit of the active G protein initially stimulates phospholipase C, which catalyzes the breakdown of membrane-bound inositol phospholipids into 2 second messenger products— IP3 and DAG
IP3 produces most of its effects by releasing stored calcium from the smooth ER.
Dag activates protein kinase C, which phosphorylates downstream regulatory proteins and transcription factors
What changes the hemoglobin dissociation curve from sigmoid to ASYMTOTIC?
Carboxyhemoglobin
Pompe disease is caused by deficiency in which enzyme? What is the normal role of that enzyme, and what happens when mutated?
Acid a-glucosidase (acid maltase)
-Constitutively degrades small amounts of glycogen that become trapped in lysosomes. Defects in acid maltase cause glycogen to accumulate within lysosomes (PAS +) resulting in hypotonia, macroglossia, hypertrophic cardiomyopathy, and death in infancy if untreated
How is stroke volume increased during exercise?
- EDV (preload) is increased resulting in increased stretch on myocytes increasing contractility
- Peripheral vascular resistance (afterload) is decreased during exercise as a result of vasodilation in muscles allows heart to empty more completely during systole resulting in decreased end-systolic volumes
- end-diastolic pressure is relatively unchanged during exercise because increased CO cancels hypotensive effect of vasodilation in exercising muscles
This disorder involves excessive thoughts or behaviors associated with one or more somatic symptoms, resulting in fuctional impairment
Somatic Symptom disorder
How does Hemoglobin F cause limited 2,3-BPG attachment?
Replacement of histidine by serine reduces positive charge of the binding pocket, limiting 2,3-BPG attachment
In an agglutination inhibition test, what does agglutination mean?
Negative result.
I 8
10 eggs
At 12
Inferior vena cava at T8
Esophagus at T10
Aorta at T12
EnFUvirtide class and mechanism
FUsion inhibitor. Inhibits HIV fusion w/ target cell membrane by binding to HIV gp 41
What part of the influenza plasma membrane mediates attachment to the host respiratory epithelium (sialic acid receptors)?
The glycoprotein hemagglutinin
Where are Lisch nodules located?
Iris hamartomas (lisch nodules) are locatedon the iris
What is the mnemonic for Sturge-Weber
SSTURGGE Sporadic port-wine Stain Tram track calcifications on opposing gyri Unilateral Retardation Glaucoma GNAQ gene Epilepsy
How does HIV reverse transcriptase work?
Converts HIV RNA into complementary double-stranded DNA
(cDNA)
Autosomal dominant familiarl cancer syndrome w/ DNA mismatch repair where patients have an increased risk of COLON, ENDOMETRIAL, and OVARIAN cancer
Lynch
Maturity-onset diabetes of the young is a group of autosomal dominant disorders that are due to mutations in?
Glucokinase (HK4, ie Hexokinase-4) gene or associated transcription factors
The first reaction of denovo pyrmidine synthesis combines glutamine, CO2, 2 ATP into carbamoyl phosphate. This is catalyzed by Carbamoyl Phosphate Synthetase II. Where does this first step occur?
Cytosol
What are the gram (-) rods that show white colonies on MacConkey agar? (Ie lactose non-fermenters)
Oxidase + organisms including pseudomonas
Oxidase - organisms including shigella, salmonella, proteus
What would Valsalva (strain phase), abrupt standing, nitroglycerin administration do to a hypertrophic cardiomyopathy patient?
Decrease preload, decrease LV volume, and increase murmur intensity
Where is the insula in respect to the Putamen? What is the role of the Insula?
THe insula is lateral to the Putamen. Its role is in subjective emotional experience, pain, body representation, and conscious cravings. In drug abusers this region demonstrates increased activity with exposure to specific cue that trigger cravings.
What drug works by inhibiting HIV entry through blocking the HIV gp120 allosteric interaction w/ CCR5?
Maraviroc
What are the two mechanisms through which intracerebral neoplasms can raise ICP?
Disruption of the blood-brain barrier (vasogenic edema) and obstruction of normal cerebrospinal fluid flow.
What are the findings in CMV retinitis and how do you treat it?
Bilateral retinal hemorrhages and cotton-wool exudates on ophthalmoscopic examination in the setting of progressive vision loss primarily in a HIV pt w/ very low CD4. Tx w/ valganciclovir, ganciclovir, foscarnet, which are agents that interfere w/ DNA replication
What drug class are the following: amlodipine, nifedipine, felodipine? What is their MOA in angina patients?
Dihydropyridine calcium channel blockers. They are selective for the smooth muscle of the peripheral vasculature rather than the myocardium
- arteriolar vasodilators that minimillay affect heart contractility/heart rate
- main effect is decreasing afterload.
Monoclonal antibody directed against CD20
Rituximab
Vaginal bleeding, extremely high bHCG, snowstorm pattern. Sonogram shows central heterogenous mass w/ numerous discrete anechoic spaces corresponds histolocially w/ trophoblastic hyperplasia and edematous chorionic villi.
Complete mole
What catalyzes the first step of oxidative burst pathway? What is this first step?
NADPH oxidase (membrane protein) catalyzes the first reaction in which an electron is transferred from NADPH to molecular oxygen, forming the reactive oxygen species, superoxide (O2.-)
Failure of nucleotide excision repair happens in what disease?
Xeroderma pigmentosum
Negative staining for p57
Seen in a complete mole, which distinguishes it from the positive p57 staining seen in partial mole
What does the HIV pol gene encode? What happens when pol gene gets a point mutation?
Pol gene encodes HIV viral protease, integrase, and reverse transcriptase
Point mutations that confer resistance against one NNRTI can cause cross-resistance of another NNRTI. Therefore if resistant to nevirapine most likely going to be resistant to efavirenz too
Reactive arthritis is the triad of urethritis, conjuctivitis, and arthritis. What are some possible cutaneous findings?
Keratoderma bennorrhagica (feet just look super disgusting and fucked up) and balanitis circinata
What is a benign breast tumor that features proliferation of stromal and ductal elements surroudned by fibrous capsule? Nontender, mobile, firm.
Fibroadenoma
Epithelial component is estrogen-sensitive, which results in size increase in pregnancy or the LUTEAL phase of the menstrual cycle
What enzyme is used by all dsDNA viruses to facilitate replication of the viral genome within the host cell nucleus?
Host cell dna-dependent dna polyermase
Injury to mid-shaft humerus results in weakness of?
Wrist extension
Membranous nephropathy, FSGS, minimal change, amyloidosis, diabetic neuropathy are all what?
Nephrotic syndromes
CDKN2A susceptibility locus on chromosome 9p21
Dysplastic Nevus Syndrome
CDKN2A encodes cyclin-dependent kinase inhibitor 2A (p16), which negatively regulates cell cycle progression at the checkpoint between G1 and S by binding and inhibiting the cyclin-dependent kinase CDK4
p16 mutations interfere with its inhibition of CDK4, allowing the cell to inappropriately advance in the cell cycle
Mechanism of cough syncope
Increased intrathoracic pressure during a coughing episode decreases venous return to the heart thereby transiently decreasing cardiac output and cerebral perfusion.
What is the mnemonic for Tuberous Sclerosis?
HAMARTOMASS Hamartomas Angiofibromas Mitral regurg Ash-leaf spots cardiac Rhabdomyoma (ventricular wall) Tuberous sclerosis autosomal dOminant Mental retardation renal Angiomyolipoma Seizures Shagreen patches
Indolent non-hodgkin lymphooma with waxing and waning lymphadenopathy and overexpression of the Bcl-2 proetin
Follicular lymphoma: lymph nodes contain tightly packed lymphoid follicles with small lymphocytes w/ cleaved nuclei and large non-cleaved lymphocytes
What is the mechanism of tretinoin for acne tx?
Decrease sebum production, normalize epidermal differentiation, increase cell turnover
Bind 2 families of retinoic acid receptors, RAR or RXR
What is in the regenerating nodules seen in liver cirrhosis?
Liver cells ie proliferating hepatocytes
Physiologic splitting of S2
Inspiration causes increased venous return to right heart, which takes more time to eject by the right ventricle=delayed P2, pulmonic valve closure
This process occurs when bacterial host DNA is packaged into a bacteriophage, which then transmits that DNA to another bacterial host. Progeny can’t be produced.
Transduction
What does Electron Microscopy show for membranous nephropathy?
Dense, subepithelial deposits that have a spike and dome appearance
What does carbamoyl phosphate synthetase I (one) do?
Catalyzes the first step of the urea cycle, in which ammonium, CO2, and 2 molecules of ATP are converted into carbamoyl phosphate. This occurs in the mitochondria**
Where do the Telencephalon and Diencephalon come from?
Prosencephalon
What type of HSR occurs when exposed to the urushiol on poison ivy plants?
Type IV, delayed cell mediated
When would you see interstitial myocardial granulomas known as Aschoff bodies?
Acute rheumatic heart disease
AtazaNAVIR, daruNAVIR, indiNAVIR, ritoNAVIR are what class of HIV drug?
Protease inhibitors
How does tetanus toxoid work?
Travels in retrograde fashion through the lower motor neurons to the spinal cord and brain stem, where it inactivates inhibitory interneurons, leading to spasm and tonic muscle contraction.
In adolescents, the transformation zone is on the exocervix (external os) and is called what?
Ectropion
What comes from the diencephalon
Thalamus and 3rd ventricle
What is the nucleotide repeat in HTT gene (Huntington disease)
CAG
Defective proline hydroxylation leads to failure of what formation?
Failure of triple helix formation and stabilization by pro-alpha chains
What are neurofibromas proliferations of?
Schwann cells: elongated, spindle shaped cells with wavy or serpinginous nuclei.
What is the origin of the Medulla and lower 4th ventricle?
Myelencephalon
DelaVIRdine, EfaVIRenz, NeVIRapine are from what drug class?
They are NNRTIs; Allosteric RT inhibitors
What are the features of alcohol-induced cardiomyopathy?
Dilated cardiomyopathy
Cardiomyocyte hypertrophy, cellular necrosis, and interstial fibrosis.
Clinically, biventricular dilation and systolic dysfunction occurs leading to syptoms of HF.
Flattened epithelial or apocrine metaplasia surroudning brown or blue fluid (Blue Dome Cyst), and compressed fibrous stroma. Also features cyclic premenstrual tenderness. Can be solitary mobile cyst or multiple diffuse nodulocystic masses
Fibrocystic changes
What is the pathophysiology of psoriasis?
- skin disruption activates APCs (dendritic cells)
- production of IFN-a, tnf-a, IL-23 by APCs induces recruitment and differentiation of T helper cells (Th17, Th1) which in turn produce additional inflammatory cytokines IL-17A, IL-22, IFN-y.
- All of these factors stimulate keratinocytes, leading to cell proliferation and production of antimicrobial peptides and additonal inflammatory cytokines; subsequently stimualtes dendritic cells again in a loop
What is the venous drainage of structure below the dentate line?
Middle and inferior rectal veins drain into the systemic circulation via the internal iliac vein
How do you find the accuracy of a ROC curve?
Accuracy is number of true positives plus true negatives divided by the number of all observations and is reflected by the area under the ROC curve.
Why is smoking the second leading risk fx for MI behind severe dyslipidemia?
Cigarette smoke generates free radicals that oxidize LDL and lead to accelerated atherosclerosis. Also causes endothelial cell dysfunction in which prostacyclin and NO production is decreased resulting in prothrombotic state
What is the most likely cause of decreased O2 sat in someone with ARDS?
Right-to-left shunting due to nonventilated alveoli.
Blood goes from right side of theheart to the left side of heart via pulmonary capillaries that are adjacent to unventilated alveoli
What is the mechanism for the development of Tardive Dyskinesia in patients on dopamine blocking agents?
Long-term blockade of dopamine receptors in the nigrostriatal dopamine pathway, causing receptor upregulation and compensatory supersensitivity of postsynaptic neurons.
DoluteGRAVIR, RalteGRAVIR are what type of HIV drug?
InteGRAse inhibitors; inhibit HIV DNA integration into host genome
Someone who has normal PNS and cholinergic sympathetic function (sweating), but has impaired sympathetic adrenergic activity (orthostatic hypotension)
Deficiency in dopamine beta hydroxylase, which converts dopamine to norepinehphrine
When mutations in different genes can elicit a similar phenotype ie like in. Amyloid precursor protein, presenilin-1, presenilin-2, may both develop early onset familial alzheimers
Locus heterogeneity
What is the venous drainage of the rectum above the dentate line?
Through the superior rectal vein, which drains into the portal venous system via the inferior mesenteric vein.
Insulin increases the activity of phosphofuctokinase-2, what is the result of this?
Fructose 2,6 bisphosphate is made from fructose-6P. F26BP activates PFK-1 and inhibits F-1,6-Pase, increasing the production of fructose1,6 BP and driving the cell toward glycolysis
What are the features of Alport Syndrome?
“Cant see, cant pee, cant hear a bee”
Mutation in type IV collagen leads to thinning and splitting of glomerular basement membrane.
X-linked DOMINANT
EM shows basket weave pattern
What is Xerosis (asteatotic dermatitis), and how do you treat it
itchy rash, dry cracked skin in older patients during winter months. It is a defect in the stratum corneum permeability barrier.
Tx focused on replenishment of water loss. Bathe w/ lukewarm water. Aggressive use of emolient moisturizers can help
Alcoholic cerebellar degeneration vs. Wernicke, Korsakoff
Alcoholic degeneration is due to long term use of alcohol leading to a chronic nutritional deficiency (often thiamine) and direct alcohol neurotoxicity. Specific pathophys underlying the disease is loss of Purkinje cells, which is most porminent in the cerebellar vermis. Wide based gait, ataxia, truncal instability. Coarse, rhythmic, postural tremor of fingers and hands, dysarthria, diplopia.
Wernicke is primarily associated w/ atrophy of the mammillary bodies and presents with the classic triad of encephalopathy, oculomotor dysfunction, and ataxia.
Korsakoff is lesions in anterior/medial thalami and presents w/ amnesia, confabulation***, and preserved long-term memory.
What do the variable opacitity proteins (Opa) of neisseria gonorrhoeae do?
They cause tighter attachment to host cell
OMP I: structural antigen used in serotyping
Opa proteins: antigenic variation (like pili) and adherence
What disease is caused by paternal microdeletion, or in 25% of cases, maternal uniparental disomy?
Prader-willi is loss of paternally inherited allele from chromosome 15. Matenally derived genes are imprinted (silenced) in this disorder.
What is the mnemonic for NF-1?
CICLOPSS Cafe au lait spots Intellectual disability Cutaneous neurofibromas Lisch nodules Optic gliomas Pheochromocytomas Seizures and focal neurologic Signs
Why is there increased aromatase and estrogen production in klinefelters patients?
Atrophied, hyalinized seminiferous tubules, resulting in small, firm testes and low inhibin levels. Leydig cells are abnormal leading to decreased Testosterone levels. Lack of feedback inhibition results in elevated FSH and LH, leading to increased aromatase activity and elevated estrogen production.
What is the mnemonic for the features of von Hippel-Lindau disease?
HARP:
Hemangioblastoma (in retina, brainstem, cerebellum, spine)
Angiomatosis
Renal cell carcinoma that is bilateral
Pheochromocytomas
Patient with severe fasting hypoglycemia, hyperlipidemia, hyperuricemia has an enlarged abdomen due to hepatomegaly and renal enlargement. Patient is fed fructose syrup and develops lactic acidosis. What disease/enzyme?
Type 1 GSD: Von Gierke
Deficiency in Glucose-6-Phosphatase
What comes from the Telencephalon
Cerebral hemispheres and lateral ventricles
What are the p450 inducers?
Most chronic alcoholics steal phen-phen and never refuse greasy carbs Modafinil Chronic alcohol St. John’s wort Phenytoin Phenobarbital Nevirapine Rifampin Griseofulvin Carbamazepine
How does VHL disease cause blood vessel proliferation?
VHL disease is caused by a deletion of the VHL tumor suppressor that is located on chromosome 3.
VHL normally codes for a gene that ubiquinates hypoxia-inducible factor 1a. Without it, cells behave as if they are in a state of hypoxia and you get the manifestations of VHL disease
Where are the immune complex depositions seen in membranous nephropathy?
Subepithelial
Where is Descemet’s membrane?
The fucking cornea
What is the only DNA virus that replicates in the cytoplasm and has own RNA polymerase and everything it needs to replicate outside the nucleus?
Pox Virus (Variola/smallpox, Molluscum contagiosum)
