Flashcards in April 20 Deck (54)
What type of cardiotoxicity is caused by doxorubicin (-rubicins)?
--caused by generation of free radicals
What immune cascade is responsible for toxic shock syndrome?
Toxic shock syndrome toxin--S. aureus or Exotoxin A--S. pyogenes---binds to MHC II and TCR (activation of macrophages and T-lymphocytes) outside of antigen binding site to cause overwhelming release of IL-1, IL-2, IFN-g and TNF-a---> Shock
A process by which a single gene can code for various unique proteins by selectively including or excluding different DNA coding regions (exons) into mature mRNA?
Potency of an inhaled anesthetic is inversely proportional to...
MAC--Minimal Alveolar Concentration---required to prevent 50% of subjects from moving in response to noxious stimulus
Lower the MAC= higher potency
Thyroid peroxidase is responsible for...
oxidation of iodide to iodine
iodination of thyroglobulin tyrosine residues
iodotyrosine coupling reaction that forms T3 and T4
Stress incontinence is defined as involuntary urine loss with increased intraabdominal pressure---kegel exercises target what structure to help with this problem?
Levator ani--improves support around urethra and bladder
What must occur in order for Hep D to cause infection?
Hep B surface antigen must coat the Hep D antigen before it can infect hepatocytes and multiply
What is the most abundant amino acid within collagen?
Glycine--helical conformation--> simple and repetetive amino acid sequence within each alpha chain where glycine occupies every third amino acid position
What is the MOA of methimazole used in hyperthyroidism?
Block thyroid peroxidase--inhibiting the oxidation of iodide and the organification (coupling) of iodine
PTU--same MOA, BUT also blocks 5' deiodinase--> decreasing peripheral conversion of T4--> T3
Activation of RAS proteins is caused by binding of what?
Binding of GDP--inactive
Mutations cause constant activation--malignant tumors
What is seen on light microscopy of pt with Guillian-Barre?
Segmental demyelination of peripheral nerves and and endoneural inflammatory infiltrate
2 y/o boy presents with fever sleepiness, vomiting. Labs show elevated ammonia, increased orotic acid in blood and urine, and decreased BUN. Dx?
Ornithine transcarbamylase deficiency
_______ are primarily responsible for sensing arterial PaO2 and can be suppressed with oxygen administration.
Peripheral chemoreceptors --carotid and aortic bodies
Pts with CF loss what in their sweat, which can lead to what?
Cl- and Na- leading to hypovolemia caused by intravascular volume contraction
Prolonged exposure to load noises leads to hearing loss due to damage to what?
Stereociliated hair cells of the organ of Corti
--High-frequency hearing loss occurs first
What is the MOA of entacapone and tolcapone used with Parkinson disease?
Prevent peripheral L-dopa degradation to 3-O-methyldopa (3-OMD) by inhibiting COMT --increasing levodopa bioavailability to the brain
What is the mechanism of action of ethosuximide used for tx of absence seizures?
Blocks thalamic T-type Ca2+ channels
What is typically the first symptom of ETOH withdrawal?
Delirium tremens --- most severe manifestation and typically begins 48-96hrs after last drink --chlordiazepoxide
Histopathology of chronic hashimoto thyroditis shows what?
Intense lymphocytic infiltrate, often with germinal centers
Residual follicles are often surrounded by Hurthle cells--large oxyphillic cells filled with granular cytoplasm
Essential fructosuria is a benign condition caused by deficiency in _______ and fructose can still be metabolized to Fructose-6-phosphate by_____.
Hereditary fructose intolerance is caused by a deficiency in _____, which presents with failure to thrive, liver and renal failure, hypoglycemia and vomiting after fructose ingestion.
Aldolase B deficiency
Formation of atheroma is mediated by what?
Release of PDGF by locally adherent platelets, endothelial cells, and macrophages
--promoting migration of smooth muscle cells from the media into the intima and subsequent proliferation
Pts with sleep apnea can have increased HCT, which is caused by what?
Renal cortical cells sensing hypoxia and respond by synthesizing and releasing EPO, which stimulates the production of erythrocytes in the bone marrow
Hydroceles and ______ inguinal hernias in an infant are caused by failure of processes vaginalis to close.
Which monosaccharide is metabolized the fastest by the liver and why?
Fructose--only one that bypasses phosphofructokinase --one of the key enzymes involved in regulating glycolysis
FNA of thyroid shows large cells with overlapping nuclei containing finely dispersed chromatin and intranuclear inclusions and grooves. Dx?
--Orphan Annie eyes
Superior sulcus tumor is also known as?
Pancoast lung tumor located in the lung apex
--causes referred shoulder pain, ipsilateral horners, and spinal cord compression
Pyruvate can take 2 separate pathways depending on availability of O2. If O2 is present then pyruvate is converted to ______ by ______. If O2 is absent then pyruvate is converted to ______ by ______.
Acetyl-CoA by pyruvate dehydrogenase--Aerobic
Lactic acid by lactate dehydrogenase--Anaerobic
--Can lead to lactic acidosis
Pts receiving blood transfusion that is greater than body blood volume (5-6L) can develop what, which is caused by what?
Hypocalcemia caused by elevated citrate levels, which is added to blood products
--The citrate chelates Ca2+ causing symptoms of hypocalcemia and hypomagnesium --causing paresthesia
What are the symptoms of stimulant (cocaine, amphetamine) withdrawal?
Intense psychomotor retardation
--acute depression with vivid dreams
What is the MOA of Flutamide and what is it used for?
Nonsteroidal competitive inhibitor at androgen receptors
---Used for prostate carcinoma
What is found in the stool of pt with strongyloides infection?
What is the cause of diastolic HF?
Decreased LV compliance
--Normal LVEF and LVEDV
--Elevated LV filling pressure
B1-adrenergic receptors are found in what two areas?
Cardiac tissue and juxtaglomerular cells
--selective blockage of B1 leads to decreased cAMP levels in cardiac and renal tissue
What drug class is useful in pts with HTN and bradycardia?
Dihydropyridines --Nifedipine, amlodipine
--Cause Vasodilation only and have to effect on cardiac tissue ---the vasodilation will cause a reflex tachycardia and with increase HR
Autosomal recessive syndrome characterized by immunodeficiency, albinism, and neurologic defects 9peripheral neuropathy, progressive neurodegeneration) --most commonly diagnosed in childhood?
Giant granules in granulocytes and platelets seen on blood smear
Defect in lysosomal trafficking regulator gene--microtubule dysfunction in phagosome-lysosome fusion
Chronic rejection of lung transplant involves what structures in the lung?
Small airways--causing bronchiolitis obliterans syndrome---dyspnea and wheezing
14 y/o male pt presents with no signs of masculinity. On PE boy has poorly develop secondary sexual characteristics. He is unable to distinguish smells. Dx and what causes this?
Kallmann syndrome--caused by defective migration of GnRH cells and formation of olfactory bulb
--decreased synthesis of GnRH in the hypothalamus, decreased GnRH, FSH, LH, testosterone
What disease has anticentromere autoantibodies?
Scleroderma --CREST syndrome
What are the extrapyramidal side effects seen with antipsychotics?
Acute dystonic reaction--Sudden on-set sustain muscle contraction
Akathisia--Subjective restlessness with inability to sit still
Drug induced parkinsonism
Isolated cleft lip results from failure of fusion of what?
Maxillary prominence fails to fuse with the intermaxillary segment during the 5th-6th wk of embryologic development
The sabin/live attenuated oral vaccine for poliovirus causes what type of immune response, when compared to the salk/inactivated vaccine?
Causes increased mucosal IgA immune response
--Offers immune protection at the site of entry for the virus by preventing attachment to the intestinal epithelial cells
Thiamine (vit B1) is a cofactor for what three metabolic pathway enzymes?
Androgens, synthesized from cholesterol in theca internal cells are transferred to ________ cells where they are converted to estrogens by ______.
Aromatase--under the influence of FSH
Cholesterol--> Androgens occurs by desmolase which is controlled by LH
Thyroid carcinoma that is characterized by nests/sheets of polygonal or spindle-shaped cells with extracellular amyloid deposits derived from calcium?
Medullary carcinoma of the thyroid--associated with MEN 2a and 2b
Lateral ankle sprain most often involves what ligament?
Anterior talofibular ligament
Patients with chronic pancreatitis/pancreatic cancer can develop gastric varices. What vein(s) are involved?
Pancreatic inflammation can cause blood clot to form in the splenic vein, which can increase pressure in the short gastric veins and lead to gastric varices in the fundus of the stomach
What causes the greenish color seen in bruises several days after injury?
Heme oxygenase coverts heme to biliverdin causing the color
Cystinuria is an AR disorder characterized by defective transport of what in the renal PCT and intestinal epithelium--which can lead to the formation of what?
Cystine, Ornithine, Lysine, Arginine--COLA
--Dibasic amino acids
Leads to formation of hexagonal cystine stones due to excess cystine in the urine
What is the MOA of the Meglitinides (Nateglinide, repaglinide)?
Stimulate postprandial insulin release by binding to K+ channels on B-cell membranes --Close ATP-dependent K+ channel inducing depolarization and L-type Ca2+ channel opening
Why is Primaquine used with P vivid/ovale malarial infections?
eradicates the intrahepatic stage (hypnozoite) preventing relapse of malaria
How is net filtration pressure calculated?
(Pc-Pi) - (nc-ni)
Glomerular capillary hydrostatic pressure--45
Glomerular capillary oncotic pressure--27
Bowman capsule hydrostatic pressure-- 10
Bowman capsule oncotic pressure--2
(45-10) - (27-2) = 10
What are the 2 key growth factors that promote angiogenesis in neoplastic and granulation tissue?
Vascular endothelial growth factor (VEGF)
Fibroblast growth factor (FGF)