Deck 4 Flashcards
What are two main uses of desmopressin (vasopressin analog)?
- Mild hemophilia/ vWF dz (increases circulating factor VIII & endothelial secretion of vWF); 2. Central DI/ nocturnal enuresis (binds V2 and inserts aquaporins; incr water reabsorption)
What are common symptoms of vWF?
Mild bleeding- during dental procedures and heavy menstrual periods
What is the most important cytokine mediator of sepsis?
TNF-a
What major host mechanism prevents infection of influenza A?
Abs against Hemagluttinin (prevents binding and neutralize)
What is the progression of lesions in syphilis?
Chancre > condyloma lata > gumma (on any organ)
Mechanism of action/ toxicity of ethambutol?
Inhibits arabinosyl transferase- SE: Optic neuropathy
What vitamin deficiency is associated with measles?
Vit A
Alternatives for MRSA with vanco allergy?
Daptomycin, linezolid
What is daptomycins MOA and limitations?
depolarizes cell membrane by creating transmembrane channels; Can’t permeate outer membrane - no gram negative use; also inactivated by surfactant - no pneumonia
What do T cells and neutrophils do for candida infection?
T cells- inhibit superficial infection; Neutrophils- prevent disseminated candidemia (Q.id 112)
Patients with chronic omeprazole Tx at increased risk of what gastroenteritis?
Cholera - acid labile
What causes the oligoclonal band on electrophoresis in MS?
Increased IgG
Inheritance of sickle cell?
Autosomal recessive
Explain the ristocetin test
Measures in-vitro vWF-dependent platelet aggregation: activates GP1b receptors to make them available. If decreased vWF then there is still poor platelet aggregation
What makes vWF and what does it adhere to? What else does it do?
Endothelial cells & megakaryocytic; Adheres to GP1b and is carrier for factor VIII (deficiency prolongs PTT)
What drug can reduce craving/ reward sensation of smoking? How? What else is a partial opioid agonist?
Varenicline: Partial agonist at a4b2 receptor (nicotin receptor in CNS); Buproprion- can precipitate withdrawal in opioid tolerant patients
What lab value is abnormal in spherocytosis?
MCHC; MCV is normal to low
Frontal lobe lesions change executive functions. Difference between right and left side?
Left side: apathy and depression. Right side: disinhibited behavior
What happens with parietal lobe damage? Left vs. right side?
Interpret visual, auditory, and motor signals; Problems in visual spatial perception; Non-dominant = hemi-neglet, denial, constructional apraxia; Dominant = Gerstmann syndrome - difficulty with writing/ mathematics
What is the progression of centriacinar emphysema? What cells are utilized?
- oxidative injury and activation of alveolar Mx 2. inflammatory recruitment of neutrophils. These cells release proteases that degrade ECF and generate free radicals. 3. leads to acinar wall destruction and airspace dilation
Which blood pressure medicine has heart benefits? How?
Mineralocorticoid receptor antag (spiron, epleren): potassium sparing, block negative effects of aldosterone on heart (causing regression of fibrosis and improved ventricular remodeling)
Patients with low B cells (Brutons) are at risk of what bacteria?
Capsulated (Abs can’t neutralize and opsonize)
Tryptophan is precursor for what?
Niacin, serotonin, melatonin
What is RT-PCR used for?
Detect and quantify mRNA: uses reverse transcriptase to create cDNA (contains exons too)
What chemicals are released in anaphylaxis?
Histamine and tryptase (specific to mast cells) from mast cells and basophilic degranulation
What sugar contributes to cataracts? What pathway?
Sorbitol; Converted by polyol pathway from glucose by aldose reductase (and then to fructose). But sorbitol accumulates faster and causes damage from osmotic activity/ oxidative stress
What hormone will increase ketones and sugar in starvation?
Hormone sensitive lipase: In adipose tissue > catalyzes stored triglycerides to FFAs + glycerol; Stimulates Gs receptors. Glycerol is used by liver for gluconeogenesis, FFAs are oxidized to acetyl CoA for ketone bodies or TCA
How can renal dysfunction affect hemostasis?
Accumulation of uremic toxins causes qualitative platelet disorder (normal PT, PTT, platelet number, long BT)
Explain cytokine process of allergy reaction?
Allergen exposure > IgM switch to IgE»_space; IgE from B lymphs and plasma cells bind Fc receptors on basophils and mast cells. Reexposure results in crosslink of bound IgE and result of cytokines (histamine, proteases (tryptase), leukotrienes, prostaglandins
What hypersensitivity reactions are C3b? IL-2? IL-4? TNF-a?
C3b: type III; IL-2: type IV (Th1 proliferation of Tcells & NK); IL-4: Th2 mediated humoral (Type I); TNF: granuloma formation but also inflammatory conditions and maybe Type IV
Whats the different substition in sickle cell vs. HbC?
HbS = glu (acidic/ negative charged) > val (non polar); HbC = glu > lys (basic/ positive charge)
What is hypo in loop diuretics and thiazides?
Thiazide = hypoK, hypoMag, (maybe hypotension, hyponatremia). Loop = hypoK, hypoMag, HypoCa
What causes S3? What does it suggest?
From sudden limitation of ventricular movement against rapid passive filling; Abnormal >40 years: suggests mitral regurg, chronic aortic regurg, HF with dilated or ischemic cardiomyopathy
When is it S3 heard best?
Heard best at left lateral decubitus at end of expiration (heart is closest to chest wall)
Risk factors for esophageal squamous carcinoma? Symptoms?
Men, >50, smoking, alcohol. Solid > liquid dysphagia, retrosternal pain, weight loss, blood loss could result in iron deficiency anemia
What is bromocryptine? What is it used for?
DA receptor agonist; inhibits pituitary prolactin secretion => restores fertility in women with hyperprolactinemia
How can you distinguish coagulopathy vs platelet disorder?
Coag = deep tissue bleeding into joints, muscles, subQ; Platelet = mucocutaneous bleeding (epistaxis, petechiae)
What is the stimulus for glycogenolysis in liver vs muscles?
Glycogen is broken down by glycogen phosphorylase a (activated with P by phosphorylase kinase); Liver = PK is activated by epi & glucagon (cAMP). Muscle = muscle contraction/ Ca and epi
What inhibits phosphorylase kinase?
ATP, Glucose-6-P
What are cholinergic agonists used for glaucoma? How do they work?
Carbachol and pilocarpine- miosis leads iris further from cornera > widened anterior chamber angle leads to better outflow of aqueous humor
