Miscellaneous Flashcards
what is tachyphylactic in terms of drug interactions?
acute decrease in response to a drug after initial/repeated administration
ex) nitrates, niacin, phenylephrine, LSD MDMA
how can Wilson disease lead to basal ganglia atrophy?
copper accumulates in the brain (basal ganglia)
how can nitroprusside cause cyanide toxicity
nitroprusside is metabolized in body to release nitric oxide and cyanide ions
how to treat cyanide toxicity
- sodium nitrite: promotes methemoglobin formation, which combines cyanide to form cyanmethemoglobin
- sodium thiosulfate: serves as sulfur donor to promote hepatic rhodanese-mediated conversion of cyanide to thiocyanate to be excreted in urine
- hydroxocobalamin: binds to cyanide ions and forms cyanocobalamin to be excreted in urine
osteocytes are connected to each other through
gap junctions
can sense mechanical stresses and send signals to modulate the activity of surface osteoblasts, so they help regulate bony remodeling
mechanism of action of colchicine
inhibits leukocyte migration and phagocytosis by blocking tubulin polymerization
used to treat acute gouty arthritis in those who can’t take NSAIDs (normally the first line treatment)
side effects: nausea and diarrhea
how does anterior dislocation of the humerus presents
flattening of the deltoid prominence, protrusion of the acromion, and anterior axillary fullness (due to humeral head’s movement into this location)
injured axillary nerve which innervates deltoid and teres minor muscles and provides sensory innervation of the skin overlying the lateral shoulder
1st pharyngeal pouch derivatives
middle ear cavity, eustachian tube, mastoid air cells
2nd pharyngeal pouch derivatives
epithelial lining of the palatine tonsil
3rd pharyngeal pouch derivatives
dorsal wings–> inferior parathyroids
ventral wings–> thymus
4th pharyngeal pouch derivatives
dorsal wings–> superior parathyroids
ventral wings–> ultimobranchial body, parafollicular (C) cells of thyroid
what is developmental field defect
multiple malformations that occur secondary to an embryonic disturbance in an adjoining group of cells
initial embryonic disturbance leads to multiple malformations by disrupting the development of adjacent tissues and structures within a particular region
what are caspases and what do they do?
proteolytic enzymes that cleave cellular proteins- activated by cytochrome c
apoptosis can occur through either intrinsic (mitochondria-mediated) pathway or the extrinsic (receptor-initiated) pathway
both pathways converge in the activation of caspases
lymph nodes of the lower extremities
divided into superficial lymphatic vessels (follow venous system) and the deep lymphatic vessels (follow the arterial system)
superficial divided into medial and lateral tracks
-medial track runs up the superficial inguinal lymph nodes, bypassing the popliteal nodes
lesions on the medial foot cause inguinal lymphadenopathy, whereas lateral lesions are more likely to cause lymphadenopathy in both the popliteal and inguinal areas
what is responsible for synthesizing cytosolic proteins
free ribosomes floating in the cytosol- translate proteins found found within the cytosol, nucleosol, peroxisome matrix, and nuclear-encoded mitochondrial proteins
the ribosomes on RER synthesizecell membrane proteins
homocystinuria-what is the cause and what happens to the individuals affected by this
cause by cystathionine synthase deficiency
affected individuals have marfanoid habitus, ectopia lentis, and developmental delay
many patients respond dramatically to pyridoxine (vitamin B6) supplementation
which are the stop codons
UAA, UAG, UGA
duchenne muscular dystrophy is caused by what type of mutation
frameshift mutations (most common) or nonsense mutations in the dystrophin gene that lead to the formation of truncated, defective protein
nonsense mutations introduce premature stop codons int he coding sequence of the mRNA
how is isoniazid metabolized
metabolized by acetylation
speed of which a patient is able to acetylate drugs depends on whether they are genetically “fast” or “slow” acetylators
what is tuberous sclerosis
autosomal dominant condition characterized by cortical tubers and subependymal hamartomas in the brain, with consequent seizures and cognitive disability, cardiac rhabdomyomas, facial angiofibromas, and leaf-shaped patches of skin lacking pigment (ask-leaf patches)
associated with renal angiomyolipoma (benign tumor composed of blood vessels (angio), smooth muscle (myo), and fat (lipoma)
amino acid binding site of tRNA
3’ CCA tail
aminoacyl tRNA synthetase is the enzyme responsible for “loading” the appropriate amino acid to the 3’ terminal hydroxyl group of the CCA tail
role of ubiquitin proteasome pathway
breakdown of intracellular proteins, both native and foreign, and helps recycle them into the amino acid building blocks
for immune response–> degrade foreign intracellular proteins and couple them to MHC I to present to CD8+ T-cells.
presentation of trisomy 18 (Edwards syndrome)
“election age”
micrognathia, prominent occiput (back of head), low-set ears, heart defects, clenched hands with overlapping fingers, renal defects, limited hip abduction, rocker-bottom feet
promoter region of transcription in eukaryotic cells
TATA and CAAT boxes located approximately 25 and 75 bases upstream form the transcription start site, respectively
primary site for ribosome synthesis and assembly
nucleolus
all ribosomal RNA except 5S rRNA is transcribed in the nucleolus
body’s reaction to high-altitude sickeness
hypobaric hypoxia
low barometric pressure so decreased pO2 in air and blood
–> tissue hypoxia stimulates peripheral chemoreceptors, causing hyperventilation in an attempt to improve oxygenation
–> decreased partial pressure of CO2 (pCO2) and increased pH (respiratory alkalosis)
–> renal bicarb excretion to compensates
increased pH, decreased pCO2 and pO2
drug and volume of distribution
if large molecular weight–> bound extensively to plasma proteins, or highly charged, then drug remaining the plasma compartment and the volume of distribution is usually low (3-5 liters)
if small molecular weight, but is hydrophilic, then can distribute into the interstitial fluid compartment outside of blood vessels and intravascular compartment (volume of distribution is limited to a total volume of about 14-16 liters (plasma + interstitial))
small molecular weight and uncharged–> dross cell membranes and reach intracellular compartment have the highest volume of distribution (41 liters)
financial arrangement:
define capitation
payer (individual, employer, or government entity) pays a fixed, predetermined fee to cover all medical services required by a patient
payment structure underlying HMO
Beers criteria: common drugs to avoid in older patients
- anticholinergic: first gen antihistamines (diphenhydramine), GI antispasmodics
- cardio: alpha-1 blockers, centrally-acting alpha-2 agonists, many antiarrhythmics
- CNS: tricyclic, antipsychotics, barbituates, benzo, and other hyponotics
- endocrine: long-acting sulfonylureas, sliding-scale insulin
- pain: non-selective NSAIDS, and skeletal muscle relaxants
drug distribution by organs
after IV administration, highly lipophilic drug will rapidly distribute to organs with high blood flow (brain, liver, kidneys, lungs)
then to tissues with lower blood flow (skeletal muscle, fate, and bone)
what causes increased ESR?
high levels of circulating fibrinogen
cytokines IL-1, IL-6, and TNF-alpha mediate systemic inflammatory response and stimulate hepatic secretion of acute-phase proteins (eg, fibrinogen)
function of prokaryotic DNA polymerase
Prokaryotes have 3 types of DNA polymerase: I, II, and III
all 3 DNA polymerases are capable of removing mismatched nucleotides via their 3’ to 5’ exonuclease (proofreading) activity
only DNA polymerase I has 5’ to 3’ exonuclease activity, which is used to remove the RNA primer synthesized by RNA primase
how does glycogen degradation synchronized with skeletal muscle contraction
due to release of sarcoplasmic calcium
calcium causes activation of phosphorylase kinase, stimulating glycogen phosphorylase to increase glycogenolysis
phosphatidylinositol 2nd messenger system
ligand binds to G protein-coupled receptor–> activates phospholipase C, which is broken down into DAG and IP3–> protein kinase C is activated by DAG and calcium–> protein kinase C phosphorylates downstream intracellular proteins to produce its physiologic effects (eg, smooth muscle contraction)
IP3 increase intracellular calcium to activate more protein kinase C
what characteristic of drugs are more likely to be processed by the liver for metabolism
drugs with more lipophilic properties
processed by liver into more polar compounds to be eliminated in bile and urine
blotting technique and what substance each detect
northern–> RNA (use single-stranded DNA or RNA (hybridization probe))
southern–> DNA (use ss DNA or RNA (hybridization probe))
western–> protein (antibody probe)
southwestern–> DNA-binding protein like transcription factors, nucleases, and histones (dsDNA probe)
what is c-Jun
DNA-binding protein
nuclear transcription factors that directly bind DNA via a leucine zipper motif
effects of different doses of dopamine
low: stimulates D1 receptors in renal and mesenteric vasculature–> vasodilation and increased blood flow to these sites
increasing doses–> stimulate beta1 and alpha 1 receptors–> increased cardiac output and eleveated systemic vascular resistance
higher dose–> increase in afterload can lead to decreased cardiac output
efficacy of drugs
refers to the intrinsic ability of a drug to elicit an effect
measure of maximum ceiling of activity (Emax) of a drug with respect to a particular pharmacodynamic end point
potency of drug
refers to dose of drug that is required to produce a given effect
affected by affinity of drug to receptor and amount of drug that is able to reach the target tissues
measure with ED50, lower the greater potency
histones
nucleosomes are composed of DNA wrapped around a core of 8 histone proteins (2 molecules each of H2A, H2B, H3, and H4)
H1 histone is located outside of this histone core and helps package nucleosomes into more compact structures by binding and linking the DNA between adjacent nucleosomes
what are P bodies
distinct foci found within eukaryotic cells that are involved in mRNA regulation and turnover
play a role in translation repression and mRNA delay and contain numerous proteins including RNA exonucleases, mRNA decapping enzymes, and constituents involved in mRNA quality control and microRNA-induced mRNA silencing
what happens to proteins destined for the lyssome
they require phosphorylation of specific mannose residues to ensure proper transit through Golgi apparatus
in the lysosome, they serve as catalysts for degradation of cellular components
triple helical conformation of collagen molecules occurs due to simple and repetitive amino acid sequence within each alpha chain with what amino acid in every third amino acid position
glycine
Gly-X-Y
common causes of Down syndrome
- meiotic nondisjunction: extra chromosome 21– based on maternal age
- unbalanced translocation: all or part of additional chromosome 21 attached to another chromosome
- mosaicism: some (not all) cells have extra copy of chromosome 21 or nondisjunction event in early embryonic life
how many half-lives does it take for the drug (metabolized by first-order kinetics) that is given by continuous infusion to reach stead state?
reach steady state in 4-5 half-lives
in hyperthyroidism, the upper eyelids are retracted, why?
hyperthyroidism induces increased expression of adrenergic receptors and leads to a hyperadrenergic state
excess adrenergic stimulation of the superior tarsal muscle causes increased resting tone and retraction of the lid
what is in each of the compartments of the leg
anterior: deep peroneal nerve, anterior tibial artery and veins
deep posterior: tibial nerve and peroneal artery and veins
lateral: superficial peroneal nerve
what is vitamin C used for in the body
necessary for hydroxylatioin of proline and lysine residues during collagen synthesis
deficiency–> capillary bleeding, poor wound healing, and periodontal disease
in children, bony deformities and subperiosteal hemorrhages
what is deficient in alkaptonuria
homogentistic acid dioxygenase
can’t convert tyrosine to fumarate so accumulation of homogentisic acid leading to black urine color when exposed to air, blue-black pigmentation on the face, and ochronotic arthropathy
what is tertiary preventsion
treating an established condition with the goal of minimizing its progression or complications
what is health promotion
process of enabling people to increase control over their health and its determinants and thereby improve their health
key findings with Patau syndrome (trisomy 13)
“puberty=13” due to secondary to meiotic nondisjunction in mothers of advanced maternal age
defective prechordal mesoderm fusion resulting in midline defects (eg, holoprosencephaly, microphthalmia, cleft lip/palate, omphalocele, polydactyly, cutis aplasia, rocker-bottom feet, renal and cardial defects,a dn umbilical hernia/omphalocele
when does linkage disequilibrium occur?
occurs with two genetic loci when their respective alleles are inherited together in the same gamete more or less often than expected by chance alone given their corresponding allele frequencies
most often occurs when the genes are in close physical proximity on the same chromosome so get crossed over together
