Flashcards in Multisystem Deck (95):
A process in which avoided ideas and emotions are inappropriately transferred to a neutral person or object
IE angry at ex girlfriend so lashes out at friend
What happens when E. coli is placed on medium only containing lactose?
Allolactose binds to the repressor
Allolactose = inducer; inactivates the reporessor -> increase in cAMP
What bacterial molecule leads a meningococcal pt to have septic shock?
Endotoxin analogous to LPS but lacks the O-Ag
Stimulates inflammatory cytokines as LPS does leading to septic shock
3 y/o has been hospitalized multiple times for infections including opportunists. He is deficient in a ligand normally expressed on activated CD4+ T cells. Dx?
X-linked, deficiency in CD40 ligand required for class switching of Ab
Deficiency in IgG with high concentrations of IgM.
Recurrent pyogenic infections and Pneumocystis pneumo.
Tx - IVIG
When a provider projects his or her own thoughts, feelings, past experiences, or issues onto a pt.
Physician doesn't education pt about payment programs because she is going through a stressful life event and the pt reminds her of her husband.
Reaction in which the pt feels anger toward the physician when the pt's expectations are not met.
2 significant side effects of ganciclovir?
Myelosuppresion and nephrotoxicity
Requires activation by a viral kinase
Inhibits viral DNA polymerase by acting as a dGTP analogue
What is true in regards to the mean median and/or mode in a positive skew?
Mean > median
What is true in regards to the mean median and/or mode in a negative skew?
Mode > median
Ab secreting plasma cells are rich in which organelle?
Prader Willi and Angelman syndrome are caused by a microdeletion of chromosome 15 and what other mechanism?
Genetic imprinting - preferential silencing of an allele by a number of mechanism - usually methylation. Others: uniparental disomy, translocation, single gene mutation
Genetic dz characterized by intellectual disability, short stature, obesity, and hypogonadism?
Loss of paternal chr 15
How do you calculate loading dose?
Cp x Vd/F
If a male pt takes clomiphene citrate for infertility, which hormone receptors would be affected?
Selective estrogen receptor modulator that acts as an antiestrogen -> increases secretion of GnRH -> increases testosterone to improve male fertility
More commonly used in female infertility
1 y/o boy has a hx of recurrent infections. He has decreased IgG and no IgM and IgA. Dx and Tx?
X linked r, defect in tyrosine kinase (BTK) associated with B cell differentiation. REcurrect bacterial infections that presents around 6 months of age.
Bone marrow transplant is contraindicated b/c T cells are functional
Infant has course facies, FTT, and developmental delay. Fibroblasts are deficient in multiple lysosomal enzymes but these enzymes are found in excess in urine and serum. Dx?
Defect in protein tagging at the Golgi complex
I - cell dz
deficienct in uridine diphospho-N-acetylglucosamine, N-acetylglucosaminyl-1-phosphatase
Normally tag lysosomal enzymes with mannose-6-P in the Golgi
primarily affects mesenchymal cells
Macrophages induce T cell to differentiate into Th1 cells by secreting?
Th1 then activates macrophages with IFN gamma
Important defense mechanism in intracellular mechanisms
What increases the melting temp of a DNA strand?
High GC content (3 bonds)
Exposure to penicillins, sulfonamides, ethosuximide, and lamotrigine can cause?
Urticaria-erythema multiforme-toxic epidermal necrolysis disorder
Begins as erythematous macules -> progress to bullae -> slough off
Mucus membrane involvement is required to dx as Stevens-Johnson syndrome
A cytokine is a potent stimulator of macrophage activity, but not B lymphocyte antibody production. What cells make this?
Secreates IFN gamma - potent stimulator of macrophages. Also has antitumor and antiviral activity
A pt gets paralytic polio after receiving OPV. LN bx reveals node architecture that lacks germinal centers. How should he be treated?
Regular IM gamma globulin injections
Pt has B lymphocyte deficiency as seen on the bx
A pt gets red man syndrome after initiation of Vanco tx. How could this be avoided?
Caused by a secondary release of histamine.
Slow 1 to 2 hour infusion of Vanco + antihistamines
How do you treat a pt overdosing on pyridostigmine?
Atropine - muscarinic antagonist
Cholinesterase inhibitor = Diarrhea, Urination, Miosis, Bronchospasm, Bradycardia, excitation, lacrimation, sweating, and salivation (DUMBBELSS)
What conditions are associated with Trisomy 21?
Acute Lymphocytic leukemia
Duodenal atresia (double bubble on CXR)
Cardiac septal defects
Which layer of the skin is only present on the palmar surface of the hands and soles of the feet?
Palmoplantar skin lacks hair follicles and is thicker than hairy epidermis
stratum lucidum is between the stratum corenum and stratum granulosum and consists of flattened keratinocytes
1st line tx of a fib?
Warfain + amiodarone
Amiodarone inhibits CYP450 and will potentiate the anticoagulating effects of warfarin
Othger inhibitors - azoles, HIVE protease inhibitors, macrolides, sulfonamides, isonaizid and H2 blockers (ranitidine and cimetidine)
10 yo has a progressively worsening, staggering gait, thick dry scaly skin, cataracts, and sensorineural hearing loss, anomia. Nerve conduction study shows delayed action potential propagation. Dx and which organelle is affected?
Involved in long-chain fatty acid metabolism, and a peroxisomal disorder can affect myelin sheath formation
Inductors of CYP450
MOA of nortriptyline?
Inhibits the reuptake mechanism responsible for terminating the action of both NE and 5HT
AEs - arrhythmia, prlonged QT, and seizures
A C. perfingens pt develops D. diff. Why?
Inhibits 50S subunit in protein synthesis
Can also be caused by ampicillin and cephalosporin
How can a teenager become emancipated?
Court order or marriage
What is the efficacy of a drug?
Maximum pharmacodynamic effect achievable with a drug
What is the potency of a drug?
The dose required to produce a given effect
If a drug is able to bind the receptors with higher affinity, then it will have greater potency
What infection precautions should be done when a pt has S. aureus?
What type of health insurance plan covers all of the employees needs in exchange for a monthly flat fee?
Payor pays a fixed predetermined fee to provide all the services required by a pt. The payors can negotiate
What is a preventable adverse event?
Injury to a pt due to failure to follow evidence based best practice guidelines
Ie - didn't check for hypothyroidism in a pt that has depressive syx
Which property should a abx have if hepatic metabolism and clearance is desired?
Kidney is usually the main site of elimination while the liver is the main site of biotransformation to prep the drug for elimination. Drugs that are more lipophilic are preferentially processed by the liver into more polar compounds for easier elimination in the bile and urine
What ABG finding would be expected in altitude sickness?
high pH, low pCO2, low O2
Following IV admin of a lipophilic drug where will it distribute?
Organs with high blood flow (brain, liver, kidneys, lungs). The drug is then redistributed to tissues with relatively lower blood flow (skeletal muscle, fat, bone).
This accounts for the short duration of action in many common anesthetics (propofol)
If a pt is told that she does not have cancer cells following a LN bx, and asks what are the chances that she really doesn't have it, which epi parameter would answer this?
Negative predictive value
Child with recurrent infections presents with Triangular facies, absent tonsils, and no thymic shadow on CXR. Deficient in which enzyme?
Absence of T cells and B cells
Low Ig levels
Mode of inheritance of Hereditary nonpolyposis colorectal cancer and neurofibromatosis type II?
NF 2 - chr 22, bilateral schwanomas
HPCC = lynch syndrome, mutation in mismatch repair. Also increased risk for endometrial cnacer
Pt presents with constant dull groin pain and edema in the right leg x weeks. Bruit is heard of RLQ. Dx?
Right common iliac artery aneurysm
Can also present with decreased urine, constipation, and palpable mass
A pt that is treated for HTN presents with abn skin findings and focal neurologic deficits. He is positive for ANA but negative for anti-DNA Ab. What drug did he take?
drug induced lupus (titanic sketch)
See antinuclear and anti-histone Ab
NO anti-dsDNA Ab
Others: procainamide, isoniazid, chlorpromazine, penicillamine, etancercept, methyldopa, and quinidine
Reversible with drug d/c
What are the locations and stimuli for thermoregulation via sweating?
Throughout the skin
Eccrine glands = thermoregulatory fxn, most numerous in palms and soles.
Secretes watery solution and are stimulated by direct sympathetic autonomic inn.
What are the characteristics of apocrine sweat glands?
Found over the axillae, areolae, genitals, and anus and are not active until puberty. Oily and viscid secretions stimulated by circulating catecholamines.
A pt presents with syx of pheochromocytoma (adrenal tumor of chromafin cells). First line tx?
Control syx via alpha blockade (nonselective irreversible alpha receptro antagonist)
What med would be contraindicated in a teenager with anorexia and depression?
Anorexia leads to electrolyte imbalances and increases a pts risk of seizures. buproprion is contraindicated in those with potential for seizures
What artery does the recurrent laryngeal n. have close contact with?
Avian influenza is not able to bind human salicyclic acid. however, following coinfection with swine influenza, the avian influenza virus is able to attach to human cells, but their progeny are not. What is this?
Coinfection of a host by 2 strains a virus results in progeny virions that contain nucleocapsid proteins from one strain and the unchanged parental genome of the other strain. NO change in the underlying genomes, just the coating
instance where multiple phenotypic manifestations result from a single genetic mutation?
One mutation affects multiple tissues manifesting as different syx
Formula for t1/2
t1/2 = (0.7xVd)/Cl
A drug is made against the molecule that recognizes the stop codon on mRNA. What is the target?
Releasing Factor 1
Releases the stop codons (UAA, UAG, UGA) to terminate protein synthesis. Facilitates the release of the polypeptide chain from the ribosome and dissolution of the ribosome-mRNA complex
What is zero-order kinetics?
Constant amount of drug is metabolized per unit of time independent of serum levels
What is first-order kinetics?
A constant fraction (or proportion) of drug is metabolized per unit of time - so the amount metabolized changes based on serum concentration
Insulin binds which type of receptors?
Insulinomas = hypoglycemia, HA/irritability, relief with caloric intake
Confirm with elevated C peptide
CD on Natural killer cells?
CD 16, also sometimes on macrophages
CD 16 = Fc receptor that recognizes IgG bound to foreign pathogens. Perforin and granzymes are released to help kill virus infected cells
Where is CD 28 found?
Receives a costimulatory signal allowing full activation of T cells by APCs. CD28 does not recognize Ab
Pt has low levels of all Ig types but normal T cells?
Infant presents with a head circumference that is lower than expected for their height and weight. VSD on cardiac exam and mom reports the baby has a strange cry. Dx?
Deletion of the short arm of chromosome 5
Microcephaly, hypotonicity, feeding difficulties, congenital heard defects and "cry of the cat"
Infant has clenched fists, rocker-bottom feet, mental retardation, and micrognathia.
Usually die within 1 year of birth
How do you avoid a type II error?
Increase the sample size
Null hypothesis is accepted even though it is actually false
Power = 1 - beta
Beta decreases as power increases
Formula for risk ratio?
risk of outcome in one group/ risk in other group
Toddler presents with worsening cough, rhinorrhea and telangias. He has multiple episodes of this. What else is he at risk for developing?
Ataxia - telangiectasia
ar, 11q22, defect in DNA repair enzymes
How do you calculate positive predictive value?
TP/(TP + FP)
Basically those that actually have the disease/those who tested positive
Depends on prevalence
When would you use a twin concordance study?
Identifying if genetic factors contribute to the development of a disease
Following an accidental stick that is risky for HBV, how should the healthcare worker be treated?
Preformed ab to neutralize the virus.
Other examples of passive immunization = tetanus, botulism, HV, Varicella, RAbies
Similar to IgG crossing the placenta
What is a Mantoux test?
Which part of the mRNA is excised out?
Exons = expressed
MOA of amantadine in post exposure flu?
Prevents viral uncoating
Binds M2 on the influeza A virus to prevent uncoating but it not used often in the US due to high levels of resistance
Also used in Parkinsons to increase the synthesis and release of dopamine from the substantia nigra
What is the first parameter to decline in FTT?
Weight, followed by height, followed by head circumference
In malignant HTN, why is sodium nitroprusside administered with sodium thiosulfate?
Prevent cyanide poisoning
Cyanide inhibits cytochrome oxidase and blocks the ETC -> decreased O2, lactic acidosis, and possibly death.
What is malignant HTN?
Very elevated blood pressure and organ damage in the eyes, brain, lung and/or kidneys. Usually seen with papilledema >200/>140
Trinucleotide repeat disorders
What do Familiar Adenomatous polyposis and BRCA1 associated breast cancer have in common?
Loss of a tumor suppressor gene
Mechanism of transposition of the great vessels?
Failure of the aorticopulmonary septum to spiral
Causes immediate cyanosis due to creation of two parallel circuits
An infant presents with hemolytic anemia shortly after birth. Direct Coombs is +. Tx?
Exchange transfusion with matched Rh- blood
The elevated bilirubin put the baby at risk for kernicterus and cerebral palsy
Which abx is only given in topical form due to its serious risk of nephrotoxicity
Inhibits peptidoglycan synthesis
Target of Griseofulvin?
alpha/beta tubulin dimer
Megaloblastic anemia - either Folate or B12 deficieny
Which type of anemia does phenytoin cause?
Blocks absorption of folate and increases utilization of folate in the body
Megaloblastic anemia due to B12 deficiency
Cause of a unilateral cleft lip?
Failure of fusion of the maxillary and medial nasal processes
Cause of a cleft palate?
Failure of fusion of the lateral palatine processes, nasal septum, and/or medial palatine process
formula for specificity?
TN/(TN + FP)
A child is hemorrhaging and the parents do not consent to blood transfusion because they are Jehovah's Witnesses. What should the clinician do?
Take the child to surgery and provide blood transfusions as medically indicated
Although parents have the right to refuse tx based on religious grounds, courts have determined that parents cannot refuse life-saving treatments for their children on this basis.
A primary intrinsic defect in the cells or tissues that form a structure leading to a chain of downstream anomalies
IE holoprosencephaly - spectrum of fetal anomalies due to incomplete division of the forebrain (or prosencephalon)
NF Kappa Beta is inhibited by?
Active NFKB is a transcription factor that is important in the immune response to infection
What test it the gold standard for identifying a microdeletion?
Pt has bilateral kidney masses composed of fat, smooth muscle, and blood vessels. What other findings might they have?
Brain hamartomas and ash-leaf skin patches
bx suggests a renal angiomyolipoma (vessel + muscle + fat).
Bilateral angiomyolipoma = tuberous sclerosis (AD)
What does improvement in nearsightedness and Age-related skin wrinkling have in common?
They're both age related changes
Presbyopia (near sight) can develop in old age and compensate for previous myopia providing a temporary improvement in vision
Who qualifies for medicare?
> 65 with a regular work history (ie paid taxes)
And younger folks with diabilities, end-stage renal dz, and ALS
What is a major cause of medical errors?
Communication failures between physicians during patient handoffs
Could be reduced by using a structured process
How would you approach a pt that uses her antidepressant on a PRN bases rather than her prescribed QD dose?
Educate her about the risks of irregular dosing
Drugs that inhibit CYP450?
Acute alcohol use