Mixed 3 Flashcards
Candida is an opportunistic infection. In an HIV patient, w/c is more common: superficial candidiasis or disseminated candidiasis?
Since T cells fight superficial infxns, an HIV pt will commonly have oral or cutaneous candidiasis. But if the patient is also taking chemotherapy that makes them neutropenic, then they are at risk of candidemia or endocarditis since neutrophils fight hematogenous spreading.
What is Maturity-onset diabetes of the young (MODY)?
MODY is due to mutations in the glucokinase gene and is characterized by nonprogressive hyperglycemia that worsens w/ pregnancy-induced insulin resistance.
>Glucokinase acts as a glucose sensor in pancreatic beta cells.
What is the formula for determining Half-life? By what order of kinetic elimination is half-life applied?
> (0.7 x Vd) / CL
>Half-life is the time needed for the plasma concentration of a drug w/ first-order kinetics to decrease by 50%.
What is the best indicator to determine the severity of mitral regurgitation?
S3 gallop is best for indicating high regurgitant volume and LV volume overload. It’s a sign of LV failure in older patients and occurs in early diastole due to sudden deceleration of entering blood as the LV reaches its elastic limit.
What is a common cause of epistaxis?
Irritation of the anterior nasal septum, w/c contains the Kiesselbach plexus, a site of anastamosis of 3 different arteries (anterior ethmoidal, sphenopalatine, superior labial arteries).
What may predispose elderly men to develop Transitional cell CA of the bladder?
> History of smoking.
>Occupational exposure to rubber, plastics, aromatic amine-containing dyes, textiles, leather.
What is the mechanism that may cause neurologic deterioration in patients w/ Huntington dse?
The CAG trinucleotide repeat of the gene coding huntingtin will result in a gain-of-fxn that leads to pathological interaction w/ other proteins. Transcriptional repression occurs when abnormal huntingtin causes inc. histone deacetylation, silencing genes necessary for neuronal survival.
How does LV outflow tract obstruction occur in hypertrophic cardiomyopathy?
HCM presents w/ asymmetric ventricular septal hypertrophy, and the thickened septum can obstruct LV outflow. The abnormal shifting of the anterior mitral leaflet toward the aortic valve also causes obstruction.
What test is used to diagnose von Willebrand disease?
Ristocetin can activate GpIb receptors and make them available for vWF binding. If vWF is decreased, there is poor platelet aggregation. When normal plasma containing vWF is added, aggregation occurs.
What deficiency causes Glanzmann thrombasthenia? What would the peripheral smear look like?
> GpIIb/IIIa receptor deficiency.
GpIIb/IIIa normally binds to fibrinogen to allow for platelet plug formation. Dx of Glanzmann thrombasthenia includes a peripheral smear w/ no platelet clumping.
How would a patient intoxicated w/ cocaine present?
Cocaine inhibits reuptake of monoamines, resulting in sympathetic stimulation (HTN, tachycardia, mydriasis) and CNS stimulation (agitation, seizures). It’s also a vasoconstrictor and can cause myocardial ischemia. If used intranasally, local ischemia can cause mucosal atrophy and nasal septal perforation.
What viral infection may Oseltamivir be used for?
Oseltamivir is a neuraminidase inhibitor for treatment of influenza. It impairs release of newly formed virions from infected host cells.
What does Abciximab do?
Abciximab is a blocker of GpIIb/IIIa, thus inhibiting binding to fibrinogen and preventing platelet aggregation. It’s used in treatment of unstable angina and acute coronary syndrome.
What are the most common adverse effects of Lithium?
Hypothyroidism and Nephrogenic diabetes insipidus.
What is the pathogenesis of Lynch syndrome (HNPCC)?
An inherited mutation in a gene responsible for DNA mismatch repair (MSH2, MLH1). This can lead to colonic adenoCA at a young age (below 50), along w/ a predisposition of extraintestinal malignancies (endometrial, ovarian).
