Mix 7 Flashcards
What’s the MOA of foscarnet in treating ganciclovir resistant CMV?
Acts as a pyrophosphate analog that inhibits DNA polymerase (also inhibits reverse transcriptase in HIV infections). Does NOT require intracellular activation by viral or cellular kinases.
Acyclovir (and ganciclovir) is a nucleoside analog. What prevents this from affecting normal host cells?
Acyclovir is a nucleoside analog that needs to be converted to its active monophosphate form by virally encoded thymidine kinase. Cellular kinases then convert the monophosphate form into the triphosphate form»_space; inhibition of herpesvirus DNA polymerase mediated replication. This is why it only affects virally infected host cells instead of those that are unaffected.
What viral infection is sofosbuvir used to treat?
Hep C. Sofosbuvir inhibits NS5B (nonstructural protein 5B), which is an RNA dependent RNA polymerase needed for Hep C replication.
What’s the MOA of using saquinavir in HIV treatment?
It acts as a protease inhibitor that prevents cleavage of the polyprotein precursors needed for generation of functional viral proteins.
In what brain structure is the pretectal nucleus found?
Superior colliculus
What cell type lines a pancreatic pseudocyst?
NONE. Pancreatic pseudocyts (due to acute pancreatitis) occur because pancreatic enzymes disrupt the walls of the pancreatic duct and leak out into the peripancreatic space, irritating the surrounding tissues»_space; granulation formation that encapsulates the fluid collection to form a pseudocyst.
What Rx would you use to prevent serotonin syndrome?
Cyproheptadine (5HT1a and 5HT2a) antagonist
What drugs are first line therapy in preventing alcohol withdrawal effects?
Benzodiazepines.
If Pt has liver disease then benzos metabolized outside of the liver (oxazepam, temazepam, lorazepam) are preferred.
Which sections of the spinal cord contain lateral gray matter horns (intermediolateral cell column)?
Thoracic and early lumbar sections
Renal angiomyolipoma is a benign tumor composed of BV, SM, and fat. Bilateral renal angiomyolipomas are associated with what disease?
Tuberous sclerosis (autosomal dominant)
Can also see cortical tubers and subependymal hamartomas in the brian»_space; seizure and cognitive disability. May also see ash leaf spots on skin.
GH can be used to help promote growth in Turner Syndrome. What kind of intracellular process happens to promote the effects of GH (what kind of receptor/pathway is activated)?
GH binds to GH receptor»_space; dimerization»_space; activation of Jak/STAT pathway (receptor phosphorylation, STAT dimerization and translocation to the nucleus)»_space; ^ IGF-1 expression.
How is glycogen breakdown synchronized with skeletal muscle contraction?
Because skeletal muscle contraction causes sarcoplasmic reticulum to release Ca2+, and Ca2+ can help activate phosphorylase kinase»_space; stimulating glycogen phosphorylase via phosphorylation to increase glycogenolysis.
Note that cAMP can also do the same thing as Ca2+ in activating phosphorylase kinase.
How does the liver regulate glycogenolysis in the fasting state (what’s the initiating event)?
In the liver, phosphorylase kinase is activated through binding of Epi and glucagon to Gs GPCR»_space; ^cAMP [ ]»_space; PKA activation»_space; phosphorylation of phosphorylase kinase (which then activates glycogen phosphorylase to break glycogen down to glucose-1P).
___ deficiency impairs FA transport from the cytoplasm into the mitochondria, preventing B-oxidation of FA into acetyl-CoA.
Carnitine deficiency. This leads to cardiac and skeletal myocyte injury (lack of ATP from citric acid cycle) and impaired ketone body production by the liver during fasting periods.
** Primary carnitine deficiency can present as muscle weakness, cardiomyopathy, elevated muscle triglycerides, and hypoketotic hypoglycemia.
What is the mechanism of desmopressin therapy in treating blood disorders like von Willebrand Disease and hemophilia A?
von Willebrand Dz = autosomal dominant deficiency of von Willebrand factor. Remember that von Willebrand factor was released by endothelial cells at sites of injury and helps in clotting by non-covalently attaching to CF VIII, increasing its stability and also helps in formation of initial platelet plug.
Desmopressin ^ release of vWF from endothelial cells.
In Hemophilia A (X linked) there is deficiency of CF VIII. Desmopressin helps increase CF VIII expression.
