biochem- micro -immuno-pharm flash facts

7/21/2019 Biochem- Micro -Immuno-Pharm Flash Facts

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IVMS FLASH FACTS-USMLE Step 1 1

IMHOTEP VIRTUAL MEDICAL SCHOOL FLASH CARD FACTS

BIOCHEMISTRY

MICROBIOLOGY

IMMUNOLOGY

PHARMACOLOGY



At which end of the tRNA isthe aa bound?

The amino acid is covalentlybound to the 3' end of the

tRNA.

Can RNA polymerase initiatechains? Yes.

Define transition.Substituting purine for purineor pyrimidine for pyrimidine.

Define transversion.Substituting purine for

pyrimidine or vice versa.




Define tRNA wobble.

Accurate base pairing isrequired only in the first 2nucleotide positions of anmRNA codon, so codons

dif

ering in the 3rd 'wobble'position may code for thesame tRNA/amino acid.

Describe DNA replication.

Origin of replication: continuous DNAsynthesis on leading strand and

discontinuous (Okazaki fragments) onlagging strand. Primase makes an RNA

primer on which DNA polymerase caninitiate replication. DNA polymerasereaches primer of preceding fragment;

5'®3' exonuclease activity of DNApolymerase I degrades RNA primer;

DNA ligase seals;

Describe DNA replication(continued answer)

3'->5' exonuclease activity of

DNA polymerase 'proofreads'each added nucleotide. DNAtopoisomerases create a nick

in the helix to relievesupercoils

Describe EuchromatinLess condensed (vs.Heterochromatin),

transcriptionally active




Describe HeterochromatinCondensed, transcriptionally

inactive

Describe key structural

dif erences betweennucleotides.

1) Purines (A,G) have 2 rings.2) Pyrimidines (C,T,U) have 1ring 3) Guanine has a ketone.

4) Thymine has a methyl

Describe single-strand,excision repair.

Excision repair-specificglycosylase recognizes and

removes damaged base.Endonuclease makes a breakseveral bases to the 5' side.Exonuclease removes shortstretch of nucleotides. DNA

polymerase fills gap. DNA ligaseseals.

Describe the dif erencebetween Eukaryotic Vs.

Bacterial, viral and plasmidorigin of replications

Eukaryotic genome hasmultiple origins of

replication. Bacteria, virusesand plasmids have only one

origin of replication.




Describe the main dif erencein eukaryotic and prokaryotic

synthesis of RNA.

Eukaryotes have 3 dif erentRNA polymerases ('I, II, III

synthesize RMT') andprokaryotes have 1 RNA

polymerase (which makes all3 kinds of RNA).

Describe the method bywhich introns are removed

from primary mRNAtranscript.

Introns are precisely spliced outof primary mRNA transcripts. A

lariat-shaped intermediate isformed. Small nuclear

ribonucleoprotein particles(snRNP) facilitate splicing by

binding to primary mRNAtranscripts and forming

spliceosomes.

Describe the number of bonds per purine-pyrimidine

pair. Which is stronger?

G-C bond (3 H-bonds) A-Tbond (2 H-bonds G-C bond is

stronger

Describe the structure of Chromatin.

Condensed by (-) chargedDNA looped around (+)

charged histones(nucleosome bead). H1 ties

the nucleosome together in astring (30 nm fiber)




Describe tRNA structure.

75-90 nucleotides, cloverleaf form, anticodon end is opposite3' aminoacyl end. All tRNAs botheukaryotic and prokaryotic, haveCCA at 3' end along with a high

percentage of chemicallymodified bases. The amino acidis covalently bound to the 3' end

of the tRNA.

Does RNA polymerase have aproof reading function? No.

How do purines andpyrimidines interact,

molecularly?

Purines and pyrimidines pair(A-T, G-C) via H-bonds

How does RNA polymerase IIopen DNA?

RNA polymerase II opens DNAat promoter site (A-T richupstream sequence- TATA

and CAAT)




How is the original RNAtranscript processed in

eukaryotes? (3)

1) Capping on 5' end (7-methyl G) 2)Polyadenylation

on 3' end ( =200 As) 3)

Splicing out of introns

In eukaryotes, what mustoccur before an newly

synthesized RNA transcriptleaves the nucleus?

Only processed RNA is

transported out the nucleusof eukaryotes.

Name 3 types of RNA 1) mRNA 2) rRNA 3) tRNA

Name the charged histonesaround which (-) chargedDNA loops (nucleosome

core).

H2A, H2B, H3, H4 histones




Name the enzyme responsiblefor the synthesis of RNA in

prokaryotes.

RNA polymerase

Name the enzymes involvedin ss-DNA repair. (5)

1) specific glycosylase. 2)endonuclease. 3)

exonuclease. 4) Danpolymerase. 5) DNA ligase.

Name the enzymesresponsible for the synthesis

of eukaryotic RNA.

RNA polymerase I RNApolymerase II RNA

polymerase III

What are exons?Exons contain the actual

genetic information codingfor a protein




What are four types of mutations that can occur in

DNA?

1) Silent 2) Missense 3)Nonsense 4) Frame shift

What are introns?Introns are intervening

noncoding segments of DNA

What are the four features of the Genetic Code?

1) Unambiguous 2)Degenerate 3) Commaless,

non-overlapping 4)Universal

What atoms link aa in aprotein chain?

Amino acids are linked N to C




What changes occur in DNAstructure during mitosis?

In mitosis, DNA condenses toform mitotic chromosomes

What codon sequence is

found at the 3' end of alltRNAs?

All tRNAs, both eukaryotic

and prokaryotic, have CCA at3' end.

What direction is DNAsynthesized in?

5' > 3'. Remember that the

5' of the incoming nucleotidebears the triphosphate

(energy source for the bond).The 3' hydroxyl of the

nascent chain is the target.

What direction is proteinsynthesized in?

Protein synthesis alsoproceed in the 5' to 3' (5' >

3')




What direction is RNAsynthesized in?

5' > 3'. Remember that the5' of the incoming nucleotide

bears the triphosphate(energy source for the bond).

The 3' hydroxyl of thenascent chain is the target.

What does the AUG mRNAsequence code for?

AUG codes for methionin,which may be removed beforetranslation is completed. Inprokaryotes the initial AUG

codes for a formyl-methionin(f-met).

What does the P in P-sitestand for? What does the A in

A-site stand for?

P-site: peptidyl; A-site:aminoacyl;

What does the statement, 'thegenetic code is commaless'mean? What is the exception

to this rule?

The code is non-overlapping.The exception are some

viruses




What does the statement, 'thegenetic code is degenerate'

mean?

More than one codon maycode for the same amino acid

What does the statement, 'the

genetic code is unambiguous'mean?

Each codon specifies only oneamino acid

What does the statement, 'thegenetic code is universal'

mean? What are theexceptions (4)?

The same code is used in alllifeforms. The exceptions are

1. mitochondria, 2.archaeobacteria, 3.

Mycoplasma, 4. some yeasts

What enzyme is responsiblefor 'charging' tRNA? How does

it work?

Aminoacyl-tRNA synthetase.

This enzyme (one per aa, usesATP) scrutinizes aa before and

after it binds to tRNA. If incorrect, bond is hydrolyzedby synthetase. The aa-tRNA

bond has energy forformation of e tide bond.




What inhibits RNA polymeraseII?

alpha-amanitin inhibits RNApolymerase II

What is a conservativemissense mutation?

Mutation results in a dif erentaa encoded, but that new aa

is similar in chemicalstructure to the original code

What is a frameshiftmutation? What is usually the

ef ect on the encodedprotein?

A change in DNA resulting inmisreading of all nucleotidesdownstream. Usually results

in a truncated protein.

What is a missense mutation?Mutation results in a dif erent

aa encoded.




What is a nonsense mutation?A change in DNA resulting in

an early stop codon.

What is a promoter?

Site where RNA polymeraseand multiple other

transcription factors bind toDNA upstream from gene

locus.

What is a silent mutation?What usually causes a silent

mutation?

Mutation results in the sameaa encoded. Often the basechange is in the 3rd position

of the codon

What is a snRNP? What is itsfunction?

snRNP = small nuclearribonucleoprotein. snRNPsfacilitate splicing by bindingto primary mRNA transcriptsand forming spliceosomes.




What is an enhancer?

Stretch of Dan that altersgene expression by bindingtranscription facts. May be

located close to, far from, or

even within (an intron) thegene whose expression itregulates.

What is an Okazaki fragment?

The discontinuous DNA

synthesized on the laggingstrand during DNA replication

What is hnRNA?hnRNA = heterogeneous

nuclear RNA The initial RNAtranscript is called hnRNA

What is responsible for theaccuracy of amino acid

selection during peptidesynthesis?

Aminoacyl-tRNA synthetaseand binding of charged tRNAto the codon are responsiblefor accuracy of amino acid

selection.




What is the broadclassification of nucleotides?

(2)

Purines (A, G) and Pyrimidines(C, T, U)

What is the dif erencebetween hnRNA and mRNA?

hnRNA = the initial RNA

transcript mRNA = cappedand tailed transcript

What is the dif erencebetween thymine and uracil?

Uracil found in RNA Thyminefound in DNA

What is the function of DNAligase during DNA

Replication?

DNA ligase seals synthesizedDNA into a continuous strand




What is the function of DNApolymerase during DNA

Replication? (2)

5'®3' exonuclease activity of DNA polymerase I degrades

RNA primer; 3'®5'exonuclease activity of DNA

polymerase 'proofreads' eachadded nucleotide.

What is the function of DNA

topoisomerase during DNAReplication?

DNA topoisomerases create a

nick in the helix to relievesupercoils

What is the function of primase in DNA Replication?

Primase makes an RNAprimer on which DNA

polymerase can initiatereplication.

What is the function of RNApolymerase I?

RNA polymerase I makesrRNA




What is the function of RNApolymerase II?

RNA polymerase II makesmRNA

What is the function of RNApolymerase III?

RNA polymerase III makestRNA

What is the mRNA initiationcodon?

AUG, or rarely GUG

What is the mRNA stopcodons? (3)

UGA (U Go Away) UAA (U AreAway) UAG (U Are Gone)




What is the result of 'mischarged' tRNA?

A mischarged tRNA (bound towrong aa) reads usual codon

but inserts wrong amino acid.

What is the role of

endonuclease in ss-DNArepair?

Endonuclease makes a breakseveral bases to the 5' side.

What is the role of excisionrepair-specific glycosylase in

ss-DNA repair

Recognizes and removesdamaged base.

What is the role of exonuclease in ss-DNA

repair?

Exonuclease removes shortstretch of nucleotides.




What prevents an incorrectaa-tRNA pairing?

If incorrect, the aa-tRNAbond is hydrolyzed by

aminoacyl-tRNA synthetase.

What role does histone H1play in chromatin structure?

H1 ties the nucleosome

together in a string (30nmfiber)

What supplies the energy forformation of peptide bond?

The aa-tRNA bond has energyfor formation of peptide

bond.

What would most likely be theresult of a mutation of the

promoter sequence?

Promoter mutation commonlyresults in dramatic decrease

in amount of genetranscribed.




When is ATP used in proteinsynthesis? When is GTP used

in protein synthesis?

ATP is used in tRNA charging,whereas GTP is used in

binding of tRNA ribosome

and for translocations.

When is recombinationinvolved in DNA repair?

If both strands are damaged,repair may proceed via

recombination withundamaged homologous

chromosome.

Where does RNA processingoccur in eukaryotes?

RNA processing occurs in thenucleus.

Which is the largest type of RNA?

mRNA (massive)




Which is the most abundanttype of RNA?

rRNA (rampant)

Which is the smallest type of RNA? tRNA (tiny)

Which nucleotide position inthe codon has room for

'wobble'?

Codons dif ering in the 3rd'wobble' position may codefor the same tRNA/amino

acid

How do you do a NorthernBlot?

Electrophorese RNA on a geltransfer to a filter expose

filter to a labeled DNA probevisualize the DNA probe

annealed to the desired RNA




How do you do a SouthernBlot?

Electrophorese DNA on a geltransfer to a filter and

denature the DNA expose toa labeled DNA probe

visualize probe annealed todesired DNA fragment

How do you do aSouthwestern blot?

Separate protein byelectrophoresis transfer to a

filter expose to a labeled DNAprobe visualize DNA bound to

desired protein

How do you do a WesternBlot?

Separate protein byelectrophoresis transfer to a

filter expose to a labeledantibody visualize Ab bound

to desired protein

How do you do PCR? (4 steps)

1. Heat DNA to denature. 2.Cool DNA and let the primers

aneal. 3. Heat-stablepolymerase replicates DNAfollowing each premer 4.

Repeat




What are some geneticdiseases detectable by PCR?

(11)

SCID, Lesh-Nyhan, CF,familial hypercholesterolemiaretinoblastoma, sickle cell, B-

thalassemia, hemophilia A

and B, von Willebrand's dz,lysosomal dz, and glycogenstroage dz

What gene is involved incystic fibrosis? CFTR

What gene is involved infamilial

hypercholesterolemia?

LDL-R

What gene is involved inLesh-Nyhan syndrome?

HGPRT




What gene is involved inretinoblastoma

Rb

What gene is involved inSCID? adenosine deaminase

What gene is involved inSickle cell and ?-thal?

? globin gene

What is an ELISA (enzymelinke immunosorbant assay)?

Rapid lab test in which an

antibody or an antigen(usually collected from a

patient) is exposed to an Agor Ab liked to to an enzyme.A positive test results in a

Ag-Ab match and is usuallyindicated b a color chan e




What is PCR?Lab procedure used to

synthsize many copies of a

desired fragment of DNA

Von Geirke's disease is aresult of?

Glucose-6-phosphatasedeficiency; also known asType I Glycogen Storage

disease

A build up of sphingomyelinand cholesterol in

reticuloendothelial andparenchymal cells and tissues

is found in what disease

Niemann-Pick disease

A child is born with multiplefractures and blue sclera what

is the diagnosis

Osteogenesisimperfecta;disease of

abnormal collagen synthesisresulting in fractures andtranslucent Conn tiss overchorioid causing the blue

sclera




A congenital deficiency of tyrosinase would lead to

Albinism, can't synthesizemelanin from tyrosine

A patient presents withcataracts,

hepatosplenomegaly, andmental retardation, what is

the Dx?

Galactosemia

A patient presents withcorneal clouding and mentalretardation that is, based onfamily history, inherited in anAutsomal recessive pattern,you impress your intern with

a Dx of

Hurler's syndrome

A patient presents with 1.Hyperextensible skin 2.Tendency to bleed 3.

Hypermobile joints youastutely Dx them with

Ehlers-Danlos syndrome




Absence of Galactosylceramide Beta-

galactosidase leads to

thebuild up of whatcompound in what disease

accumulation of galactocerebroside in the

brain; Krabbe's disease

Absence of hexosaminidase Aresults in the acumulation of

what molecule that ischaracteristic of what disease

GM2-ganglioside

accumulation; Tay-Sachsdisease

albinism increase risk of developing what

skin cancer

Autosomal dominant defectswill ef ect what members of a

family

male and female




Autosomal recessivedisorders often result in what

kind of defect/deficiencie?

enzyme deficiencies

Autosomal recessive

disorders usually ef ect howmany generations in a family?

usually only one generation

Bloom's syndrome ischaracterized by sensitivity to

what as a result of

sensitivity to radiation as aresult of a DNA repair defect

Creatine and Urea are bothmade from?

Arginine




Defects in structural genesoften follow what pattern of

inheritance?

Autosomal dominant

Defiency of arylsulfatase A

results in the accumulation of what molecule where

sulfatide in the brain, kidney,liver, and peripherla nerves.

Characteristic of MetachromaticLeukodystrophy

define genetic imprintingwhen dif erences in

phenotype depend onwhether the mutation is of paternal or maternal origin

define incomplete penetrancewhen not all individuals witha mutant genotype show the

mutant phenotype




define Linkage Disequilibrium

the tendency for certainalleles at two linked loci tooccur together more often

thatn expected by chance, asmeasured in a population

define pleiotropy

one gene has more than oneef ect on an individual's

phenotype, autosomaldominant defects are oftne

pleiotropic

Define variable expressionnature and severity of thephenotype varies from one

individual to another

Fanconi's anemia is caused bywhat typr of agents

cross-linking agents




Ganglioside is made up of what

Ceramide + oligosacharide +sialic acid

Gaucher's disease is causedby a deficiency of Beta-glucocerebrosidase

Glucocerebrosideaccumulation in the brain,

liver, spleen, and bonemarrow are characteristic of

Gaucher's disease

Hglycine is used to makewhat important compound

Porphyrin which is then usedto make Heme




Histamine is synthesizedform what compound

Histidine

How does adenosine

deaminase defiency causeSCID

Purine salvage pathway. ADAnormal converts adenosine toinosine without it ATP &

dATP build up inhibitingribonucleotide reductasewhich prevents DNAsynthesis lowering

How is Lesch-Nyhansyndrome inheritied andwhatis the result and symptoms

X-linked recessive; increasein uric acid production.

Retardation, self mutalation,aggression, hyperuricemia,gout, and choreathetosis

Hunter's syndrome ischaracterised by what

biochemical problem and howis it inherited

deficiency of iduronatesulfatase; X-linked recessive

mild form of Hurler's




In ataxia-telangiectasia DNAdamage caused by what

source cannot be repaired

X-rays

in G6PD deficiency the

decrease in NADPH can leadto _____ if exposed to _____

hemolytic anemia;oxidizingagents( fava beans,

sulfonamides, primaquine)and antituberculosis.

In PKU what builds up andwhat can be found in the

urine

phenyalanine builds upeleading to phenylketones in

the urine

In PKU, what amino acidbecomes essential

tyrosine.




in the Hardy-Weinbergequation, what are the p and

q and what is 2pq

p and q are each separatealleles; 2pq = heterozygote

no male to male transmission

is characteristic of what typeof genetic disorders?

X-linked recessive

Pompe's disease is caused bya defect in?

lysosomal alpha-1,4-glucosidase defiency

Sickle cell anemia is causedby what defect and what is

it's prevalence

AR single missense mutationin the beta globin; 1:400

blacks




Siclkle cell anemia patientsoften present with

recurrent painful crisis andincreased susceptibility to

infections

Skin sensitivity to UV lightsecondary to a DNA repairdefect is characteristic of

what?

xeroderma pigmentosum

Sphingosine + fatty acidyields

ceramide

the COL1A gene mutation isassociated with what diseaseand what type of mutation is

this

Osteogenesisimperfecta;dominant negitive

mutation




The main defect in Ataxia-telangiectasi is a ___

DNA repair defect

The most common form of Osteogenesis imperfecta haswhat genetic problem and

inheritance

abnormal Collagen Type I

synthesis;Autosomaldominant

the transporter for whatamino acids is defective in

cystinuria

COLA: Cys,Ornithine, Lysineand Arginine

Thymidine dimers are formedby exposure of DNA to UV

light, are the dimers formedon the opposing strands of aDNA molecule or on the same

side?

dimers are on same side




Tryptophan can be used tomake what three chemicals

Niacin, 'Serotonin, melatonin

Type III Glycogen storagedisease is a defiency of ?

deficiency of debranching

enzyme alpha-1,6-glucosidase

What is the cause Tx andsymptoms of Lactase

intolerance?

Lactase defiency, avoid diaryproducts or add lactse pills to

diet symptoms bloating,cramps, osmotic diarrhea

What % of kids born to fatherwith mitochondrial myopathie

will be ef ected

none, mitochondrialmyopathies are inherited

from mitochondria which isonly inherited from the

mother




What are the clinical signs of Krabbe's disease

optic atrophy, spasticity, earlydeath

What are the components of Cerebroside

Ceramide + glucose/galactose

What are the components of Sphingomyelin

Ceramide +phosphorylcholine

What are the components of sphingosine

serine + palmitate




What are the findings andtreatment of pyruvate

dehydrogenase

neurologic defects; increaseintake of ketogenic nutrients

What are the findings in

McArdles's disease and whatis the problem

increased glycogen in skeletalmuscle due to a Glycogenphosphorylase defiency

strenuous exercise causemyoglobinuria and painful

cramps

What are the findings in PKUand what is the treatment

Mental retardation, fair skin,eczema, musty body odor Tx.

Decreasee phenylalanin(nutrasweet) and increase

tyrosine

What are the findings inPompe's disease and what is

it alternate name

Cardiomegaly and systemicfindings, leading to early

death. Pompe's trashes thePump. (Heart, Liver and

muscle) Type II Glycogenstorage disease




What are the findings in VonGierke's disease

severe fasting hypoglycemia,increased glycogen in the

liver

What are the four

assumptions of the Hardy-Weinberg equilibrium

1.There is no mutationoccuring at the locus 2. Thereis no selection for any of the

geno types at the locus 3.Random mating 4. no

migration in or out

What are the purely ketogneicamino acids

lysine and leucine

What are the signs andsymptoms of essential

fructosuria

asymptomatic, benign,Fructose appears in blood

and urine




what are the signs andsymptoms of Homocystinuria

Homocysteine accumulates inurine and cystine becomes

essential Methionine and it'smetabolites build up in blood

Mental retardation,osteoporosis, dislocation of the lens

What are the symptoms of Alkaptonuria

Dark Urine from alkaptonbodies; also connective tissueis dark, may have arthralgias.

Bengin disease

What are the symptoms of Fructose intolerance

hypoglycmeia, jaundice,cirrhosis

What are the symptoms of Maple syrup Urine disease

CNS defects, mentalretardation and death. Urine

smells like maple syrup




What biological chemicals arederived form phenylalanine

tyrosine, thyroxine Dopadopamine NE, Epinephrine

and Melanin

What causes EssentialFructosuria defect in fructokinase

What causes Lesch-Nyhansyndrome

Absence of HGPRTase,

(normally convertshypoxanthine to IMP andguanine to GMP) Lacks

Nucleotide Salvage (LNS)-purines

What do melanin andNorepinephrine have in

common

both derived directly fromdopamine Phenylalanine to

tyrosine to Dopa to Dopamin




What does the term 'loss of heterozygosity' mean

when one allele of an allele pair islost. An example is when a

patient inherits or develops amutation in a tumor suppressor

gene and the complimentaryallele is then lost to deletion/

mutation. The patient would notdevelop the cancer until the loss

of the normal allele.

What enzyme defiencies are

associated with hemolyticanemia

Glycolytic enzymedeficiencies 1. Hexokinase

2.glucose-phosphate

isomerase 3.aldolase4.triose-phosphate isomerase5. phosphate-glyceratekinase enolase pyruvate

What event in embryology cancause albinism

lack of migration of neuralcrest cells to skin (form

melanocytes)

What genetic error can causeSevere Combined

Immnuodeficiency (SCID)?

Adenosine deaminasedeficiency




what group of people can beseen with pyruvate

dehydrognease deficiency

alcoholics due to B1defiecincy

What is a complication of cystinuria cystine kidney stones

What is a dominant negitivemutation?

a mutation that exerts a

dominant ef ect because thebody cannot produce enoughof the normal gene product

with only one allelefunctioning normally

What is a good pnuemonic forthe four glycogen storage

diseases

Very-Von Gierke's Poor-Pompes Carbohydrate-Cori's

Metabolism-McArdles




What is commonly associatedwith xeroderma pigementosa?

dry skin, melanoma and othercancers

What is crucail to the

diagnosis of an Autosomaldominant disease?

Family history

What is genetic anticipation?the severity of the diseas

worsens or age of onset of disease is earlier in

succeeding generations

What is inheritance of G6PDdfiency and what population

is ef ected more often

X-linked recessive; blacks




What is NAD/NADP madeform

Niacin, 'Serotonin, melatonin

What is osteogenesis

imperfecta often confusedwith

child abuse

What is the biochemicaldefect in Metachromatic

leukodystrophy and what isthe inheritance pattern

deficiency of arylsulfatase A;Autosomal recessive

What is the biochemicaldefect in Nieman-Pickdisease and how is it

inherited

deficiency of Beta-glucocerebrosidase;autosomal recessive




What is the biochemical ef ectof G6PD defiency

decrease in NADPH which isnecessary to reduce

glutathione which in turn

detoxifies free radicals andperoxides

What is the cause of

Cystinuria and what are thesigns/symptoms

inheritied defect o the tubularamino acid transporter for

Cystine, ornithine, Lysine andArginine in kidneys excess

cystine in urine

What is the cause of Fabry'sdisease and what is the

common clinical problem

Alpha-galactosidase Adeficiency; gives

accumulation of ceramidetrihexoside causing renal

failure

What is the cause of galactosemia?

Absence of galactose-1-phosphate uridyltransferase;

accumualtion of toxicsubstances (galactitol)




What is the characteristicdefect in Hurler's syndrome

Alpha-L-iduronidase defiencyleads to corneal clouding and

mental retardation

What is the characteristicfindings in Neurofibromatosis

Multiple café-au-lait spots,

neurofibromas increasedtumor susceptibilty

What is the clinical picture of a patient with cystic fibrosis

pulmonary infections,exocrine pancreatic

insuciency, infertility inmen

What is the clinical picture of Duchenne's muscular

dystrophy

muscular weakness anddegeneration




What is the defect in MapleSyrup Urine disease

decreased Alpha-ketoaciddehydrogenase. blocks

degradation of branched

amino acids Ile. Val. Leu

What is the epidemiology of lactose intolerance

Age-dependnet and/orhereditary (blacks and Asians)

What is the etiology of Homocystinuria

defect in cystathionine

synthase. Two forms: 1.deficiency 2. decreasedanity of synthase forpyridoxal phosphate

(cofactor)

What is the finding of Hunter's syndrome on

H&P

mild mental retardation butno corneal clouding




What is the formula forHardy-Weinberg equilibrium?

p^2 +2pq + q^2 =1 and p+q=1

What is the genetic mech. Of

Cystic fibrosis and it'sinheritance

AR; multiple loss-of-function

mutations in a chloridechannel

What is the geneticmechanism of Duchenne's

muscular dystrophy

X-linked recessive;caused bymultiple loss-of-funtion

mutations in a muscle protein

What is the geneticmechanism of Fragile X MR

X-linked; progressiveexpansion of unstable DNAcauses failure to express

gene-encoding RNA-bindingprotein




what is the geneticmechanism of

Neurofibromatosis

AD, multiple loss-of functionmutations in a signaling

molecule

What is the genetic problemin Down's Syndrome

trisomy 21 chromosomalimbalance

What is the inheritance of Krabbe's disease

Autosomal recessive

what is the inheritancepattern and carrier frequency

in Tay-Sach's

Autosomal recessive; 1:30 in Jews of European descent and

1:300 in the generalpopulaition




What is the inheritancepattern of Ehlers-Danlos

syndrome

10 types of this syndromeType IV-Auto Dominant TypeVI-Auto Recessive Type IX-

X-linked recessive

What is the inheritancepattern of Gaucher's disease Autosomal recessive

What is the inheritancepattern of xeroderma

pigmentosa

autosomal recessive

What is the inheritiancepattern of Fabry's disease

X-linked recessive




What is the lab symptoms of G6PD defiency

Heinz Bodies: alteredhemoglobin precipitate in

RBC

What is the mostdistinguishing finding in Tay-

Sach's disease on Physicalexam

cherry red Macula; thesepatients die by 3

What is the pathogneumoniccell type founde in Gaucher's

disease

Gaucher's cells with thecharacteristic 'crinkled paper'

appearance of enlargedcytoplasm

What is the pattern of inheritance of Leber's

hereditary optic neuropathy?

mitochondrial inheritance




What is the phenotype inOsteogenesis imperfecta

increased susceptibility tofractures;connective tissue

fragility

What is the phenotype of Down's syndrome

Mental and growthretardation, dysmorphic

features, internal organanomalies especially heart

problems

What is the phenotype of Fragile X

mental retardation,characteristic facial features,

large testes

What is the predominantproblem in Ehlers-Danlos

syndrome

Faulty collagen synthesis




What is the prevalance of cystic fibrosis

1:2000 whites; very rareamong Asians

What is the prevalandce of Neurofibromatosis

1:3000 with 50% being newmutations

What is the prevalence of Down's syndrome and what

are the risk factors

1:800; increased risk withadvanced maternal age

What is the prevalence of Duchenne's musc. dys.

1:300; 33% new mutations




What is the prevalence of Fragile X- associated mental

retardation

1:1500 males: can be infeamales is a multi-step

process

What is the prevalence of osteogenesis imperfecta 1:10000,

What is the prevalence of Phenylketonuria

1:10000

What is the priamry defect inFructose intolerance and how

is it inherited?

defiency of aldolase B,autosomal recessive




What is the primary defect inAlkaptonuria

congenital defiency of homogentisic acid oxidase in

the degradative pathway of

tyrosine

What is the primary defect(s)found in Phenylketoneuria

either 1.decreasedphenylalanie hydroxylase or

2. decreasedtetrahydrobiopterin cofactor

What is the rate-limitingenzyme in the Hexose-Monophosphate shunt?

Glucose-6-phosphatedehydrogenase

What is the result of pyruvatedehydrognease deficiency

backup of substrate (pyruvateand alanine) resulting in lactic

acidosis




What is the specific defect inXeroderma pigmentosa

defective excision repair suchas uvr ABC exonuclease; haveinability to repair thymidine

dimer formed by UV light

What is the treament of Cystinuria and what is a

possible consequence of nottreating

Acetazolide to alkinlize the

urine cystine kidney stonesdue to excess cysteine

What is the treatment of fructose intolerance?

decrease intake of bothfructose and sucrose (glucose

+ fructose)

What is the treatment of Homocystinuria

1. For a defiency incystathionine synthase tx bydecrease Met and increaseCys in diet 2. for decreasedanity of synthase Tx by

decrease vitamin B6 in diet




What is the Tx of galactosemia?

Exclude galactose and lactose(galactose +glucose) form

diet

what of spring of femalesaf ected with a mitochondrial

inherited disease will beef ected?

all of spring can be ef ected

what percent of of springfrom two autosomal recessive

carrier parents will beef ected?

25%

what percent of sons of aheterazygous mother carrying

an x-linked disease will beef ected?

50%




What period of life doautosomal dominant defects

present in?

often present clinically afterpuberty

What three phenyl ketones

build up in the urine of PKUpatients

phenylacetate, phenyllactate,phenylpyruvate

What to thyroxine and Dopahave in common

both derived form tyrosine

What type of genetic error isusually more severe

autosomal recessive ordominant?

AR disorders are often moresevere




What bacteria causes amalignant pustule (painless

ulcer); black skin lesions that

are vesicular papules coveredby a blak eschar?

Bacillus anthracis

What bacteria exhibits a'tumbling' motility, is found in

unpasteurized milk, andcauses meningitis in

newborns?

Listeria monocytogenes

What bacteria is catalase(-)and bacitracin-resistant?

Strep. agalactiae

What bacteria is catalase(-)and bacitracin-sensitive?

Strep. pyogenes




What bacteria is catalase+and coagulase+?

Staph. aureus

What bacteria producesalpha-toxin, a hemolytic

lecithinase that causesmyonecrosis or gas

gangrene?

Clostridium perfringens

What bacterium causesCellulitis?

Pasteurella multocida

What bacterium causesleprosy?

Mycobacterium leprae




What bacterium causes Lymedisease?

Borrelia burgdorferi

What bacterium causes thePlague? Yersinia pestis

What bacterium causesTularemia?

Francisella tularensis

What bacterium causesUndulant fever?

Brucella spp. (a.k.a.Brucellosis)




What bug causes atypical'walking' pneumonia?

Mycoplama pneumoniae

What bug causes

gastroenteritis and up to 90%of duodenal ulcers?

Helicobacter pylori

What bug causesLegionnaire's disease?

Legionella pneumophila

What bug is associated withburn wound infections?

Pseudomonas aeruginosa




What bug is comma- or S-shaped and grows at 42C,

and causes bloody diarrhea

with fever and leukocytosis?

Campylobacter jejuni

What bug that causesdiarrhea is usually

transmitted from pet feces(e.g. puppies)?

Yersinia enterocolitica

What causes tetanus? (givebacteria and disease process)

Clostridium tetani: exotoxinproduced blocks glycine

release (inhibitory NT) fromRenshaw cells in spinal cord

What causes the flu?NOT H. flu -it is caused by

influenza virus




What chemical is found in thecore of spores?

dipicolinic acid

What coccobacillus causesvaginosis: greenish vaginal

discharge with a fishy smell;nonpainful?

Gardnerella vaginalis

What disease does Bordetellaperussis cause? How?

Whooping cough: toxin

permanently disables G-protein in respiratory mucosa

(turns the 'of ' of );ciliatedepithelial cells are killed;

mucosal cells are overactive.

What disease does Vibriocholerae cause? How?

Cholera: toxin permanentlyactivates G-protein in

intestinal mucosa (turns the'on' on) causing rice-water

diarrhea




What disease is caused byBorrelia?

Lyme Disease

What disease is caused by

Clostridium botulinum? Whatpathophys. does it cause?

Botulism: associated withcontaminated canned food,

produces a preformed, heat-labile toxin that inhibits ACh

release---> flaccidparalysis.

What diseases (2) are causedby Treponema?

Syphilis (T. pallidum) -yaws(T. pertenue; not and STD)

What diseases can be causedby Staph. aureus?

Inflammatory disease: skin

infections, organ abcess,pneumonia - Toxin-

mediated disease: ToxicShock Syn., scalded skin

syndrome (exfoliative toxin),rapid onset food poisoning

enterotoxinsIVMS FLASH FACTS-USMLE Step 1 199



What do Chlamydiatrachomatis serotypes A, B,

and C cause?

chronic infection, causeblindness in Africa (ABC=

Africa / Blindness / Chronic

What do Chlamydia

trachomatis serotypes D-Kcause? (3)

urethritis/ PID - neonatal

pneumonia -neonatalconjuctivitis

What do Chlamydiatrachomatis serotypes L1,L2,

and L3 cause?

lymphogranuloma venereum(acute lymphadentis: positive

Frei test)

What do RMSF, syphilis, andcoxsackievirus A infection

have in common?

rash on palm and sole is seenin each (coxasackievirus A=hand, foot, and mouth

disease)




What does catalase do? Whichbacteria have it?

it degrades H2O2, anantimicrobial product of

PMNs. - Staphlococci make

catalase; Strep. do NOT.

What does the H-antigenrepresent?

H: flagellar antigen, found onmotile species

What does the K-antigenrepresent?

K: capsular, relates tovirulence

What does the O-antigenrepresent?

O-antigen is thepolysaccharide of endotoxin

(found on all species)




What family includes E. coli,Salmonella, Klebsiella,

Enterobacter, Serratia, and

Proteus?

Enterobacteriaceae

What family of bacteria uses

the O-, K-, and H-antigennomenclature?

Enterobacteriaceae

What function does thecapsule serve? (2: one for the

bacterium, one other)

1) antiphagocytic 2) antigenin vaccines (Pneumovax, H.

flu b, meningococcalvaccines)

What G+ anaerobe causesoral/facial abscesses with'sulfur granules' that may

drain through sinus tracts inskin?

Acinomyces israelii




What G+ and also weakly acidfast aorobe found in soil

causes pulmonary infections

in immunocompromisedpatients?

Norcardia asteroides

What general type of bacteria

are normal flora in GI tractbut pathogenic elsewhere?

Anaerobes

What general type of bacteriagrow pink colonies on

MacConkey's agar?

Lactose-fermenting entericbacteria

What is a Ghon complex andin whom does it occur?

Occurs in Primary TB (usuallya child) -Ghon complex=draining Hilar nodes andGhon focus, exudative

parenchymal lesion (usu. inLOWER lobes of lung)




What is a lab diagnosis of diphtheria based on?

G+ rods with metachromaticgranules; grows on tellurite

agar. (Coryne=club shaped)

What is a major dif erence

between Salmonella andShigella observable in the lab?

Salmonella are motile;Shigella are nonmotile

What is a positive Quellungreaction?

if encapsulated bug ispresent, capsule SWELLS

when specific anticapsularantisera are added.

What is notable aboutChrmydia psittaci?

has an avian reservoir




What is one reason M. leparaeinfects skin and superficial

nerves?

It likes cool temperatures

What is the classic symptomof Lyme Disease?

erythema chronicum migrans,

an expanding 'bull's eys' redrash with central clearing.

What is the classic triad of symptoms associated with

Rickettsiae?

1) headache 2) fever 3) rash(vasiculitis)

What is the commonmanifestation of secondary

TB?

Fibrocaseous cavitary lesionusu. in APICIES of lung




What is the common site of infection for Mycobacterium

tuberculosis?

the apicies of the lung (whichhave the highest PO2)

What is the D.O.C. to treatGardnerella vaginalis? Metroidazole

What is the DOC for treatingrickettsial infections?

tetracycline

What is the DOC fortreatment of most rickettsial

infections?

tetracycline




What is the DOC to treatLyme Disease?

tetracycline

What is the DOC to treatsyphilis? Penicillin G

What is the drug of choice forH. flu meningitis? What DOC

for prophylaxis in close-contacts?

Treat meningitis withCEFTRIAXONE; Rifampin for

prophylaxis.

What is the drug of choice forLegionaires' disease?

Erythromycin




What is the morphology of H.flu?

Small G(-) (coccobacillary) rod

What is the morphology of H.pylori? Gram (-) rod

What is the primary drugused to treat leprosy?

dapsone (toxicity is hemolysisand methemoglobinemia)

What is the recommendedtreatment for Pseudomonas

aeruginosa infection?

aminoglycoside plusextended-spectrum penicillin(e.g. piperacillin or ticarcillin)




What is the source of infection and the bacterium

that causes endemic typhus?

R. typhi; from fleas

What is the source of

infection and the bacteriumthat causes epidemic typhus?

R. prowazekii; from humanbody louse

What is the source of infection and the bacterium

that causes Q fever?

Coxiella burnetii; frominhaled aersols

What is the source of infection and the bacteriumthat causes Rocky Mountain

Spotted Fever?

Rickettsia rickettsii; from tickbite




What lab test assays forantirickettsial antibodies?

Weil-Felix reaction

What Lancefield AntigenGroup are enterococci in? Group D

What Lancefield AntigenGroup are Viridans strep in?

They are non-typealbe. Theydo not have a C-carbohydrate

on their cell wall to beclassified by.

What level of disinfection isrequired to kill spores?

autoclaving; they are highlyresistant to destruction by

heat and chemicals




What populations are mostlikely to get Mycoplama

pneumoniae infection?

patients younger than age 30- military recruits - prisons

What rickettsial disease isatypical in that it has no rash,no vector, negative Weil-Felix

reaction, and its causativeorganism can survive outside

for a long time?

Q fever (Coxiella burnetii)

What species are associatedwith food poisoning incontaminated seafood?

Vibrio parahaemolytica andVirbrio vulnificus

What species causesdiphtheria?

Corynebacterium diptheriae




What species is associatedwith food poisoning in

improperly canned foods

(bulging cans)?

Clostridium botulinum

What species is associated

with food poisoning in meats,mayonnaise, and custard?

Staphylococcus aureus (this

food poisoining usu. startsquickly and ends quickly)


poultry, meat, and eggs?

Salmonella

What species is associatedwith food poisoning inreheated meat dishes?

Clostridium perfringens





reheated rice?

Bacillus cereus ('Foodpoisoning from reheated rice?

Be serious!')

What species is associatedwith food poisoning inundercooked meat andunpasteurized juices?

E. coli 0157-H7

What species of Mycobacteriacauses pulmonary, TB-like

symptoms?

M. kansasii

What strain of Haemophilusinfluenza causes most

invasive disease?

capsular type b




What symptoms areassociated with M.

scrofulaceum

cervical lymphadenitis in kids

What test dif erentiatesViridans from S. pneumoniae?

Viridans are resistant to

optochin; S. pneu. aresensitive to optochin

What two bugs secrete

exotoxins that act via ADPribosylation of G-proteins,

permanently activating adenylcyclase (resulting in increased

cAMP)?

Vibrio cholerae - Bordetellapertussis

What two genera of G+ rodsform long branching

filaments resembling fungi?

Acinomyces and Nocardia




What type of bacteria aredicult to culture, producegas in tissue (CO2 and H2),

and are generally foul-smelling?

Anaerobes

What type of bacteria isassociated with rusty sputum,

sepsis in sickle cell, andsplenectomy?

Pneumoccocus

What type of E. coli areassociated with bloody

diarrhea?

enterohemmoragic/enteroinvasive E. coli

What type of immunologicresponse is elicited by a

Salmonella infection?

monocyte response




What types of infection canchlamydia cause? (4)

arthritis - conjunctivitis -pneumonia - nongonococcal

urethritis

What virulence factor of Staph. aureus binds Fc-IgG,

inhibiting complementfixation and phagocytosis?

Protein A

What virulence factor of Strep. pyogenes also servesas an antigen to which the

host makes antibodies?

M-protein

What will likely be visibleunder the microscope in thecase of Gardnerella vaginallis

infection?

Clue cell, or vaginal epithelialcells covered with bacteria




Where are Viridans strep.found (reservoir)?

normal flora of oropharynx

Where are when is Lymedisease common?

common in northeast US insummer months

Which disease/toxin causeslymphocytosis? (Cholera or

Pertussis)

Pertussis toxin: by inhibitingchemokine receptors

Which has an animalreservoir? (Salmonella or

Shigella)

Salmonella: poultry, meat,eggs




Which is more specific forsyphilis: VDRL or FTA-ABS?

FTA-ABS is more specific

Which is more virulent?(Salmonella or Shigella)

Shigella (10^1 organisms vs.Salmonella 10^5 organisms)

Which is motile? (Salmonellaor Shigella)

Salmonella (think: salmonswim)

Which species of chlamydiacauses and atypical

pneumonia? How is ittransmitted?

C. pneumonia -transmittedvia aeresol




Which two species of chlamydia infect only

humans?

C. trachomatis -C.pneumoniae

Why are anaerobessusceptible to oxygen?

they lack catalase and/or

oxidase and are susceptibleto oxidative damage

Why does TB usually infectthe upper lobes of the lung?

M.tuberculosis is an aerobe;there is more oxygen at the

apicies

Why must rickettsia andchlamydia always be

intracellular?

they can't make their ownATP




Are most fungal sporesasexual?

yes

Are most P. Carinii infectionssymptomatic? no, most of are asymptomatic

Are the above mentionedsystemic mycoses dimorphic?

yes, except coccioidomycosiswhich is a spherule in tissue

How do the S. Schenckii yeastappear in the pus?

Cigar-shaped budding yeast




How do you Tx S. Schenckii?Itraconazole or Potassium

Iodide

How does Aspergillus appearmicroscopically?

Mold with septate hyphaethat branch at a V-shaped (45degree angle) , they are NOT

dimorphic

How does Mucor speciesappear microscopically?

It is a mold with irregularnonseptate hyphae branchingat wide angles>90 degrees

How doesParacocciodioidomycosis

appear histologically?

Captain's wheel' appearance(like on a sailboat)




How is Clonorchis sinensistransmitted and what disease

results?

undercooked fish; causesinflammation of the biliary

tract

How is Schistosoma

transmitted and what diseaseresults?

snails are host; cercariaepenetrate skin of humans;

causes granulomas, fibrosis,and inflammation of the

spleen and liver

How is AncylostomaDuodenale transmitted and

what disease results?

Larvae penetrate skin of feet;intestinal infection can cause

anemia

How is Ascaris Lumbricoidestransmitted and what disease

results?

Eggs are visible in feces;intestinal infection




How is cryptosporidiumtransmitted?

Cysts in Water

How is Dracunculus

medinensis transmitted andwhat disease results?

In drinking water; sinkinflammation and ulceration

How is E. granulosistransmitted and what disease

results?

Eggs in dog feces cause cystsin liver; causes anaphylaxis if

echinococcal antigensreleased from cysts

How is E. Histolyticatransmitted?

Cysts in Water




How is EnterobiusVermicularis transmitted and


food contaminated with eggs;intestinal infections; causes

anal pruritus

How is giardia transmitted? Cysts in Water

How is Loa loa transmittedand what disease results?

Transmitted by deer fly;causes swelling the in the

skin (can see worm crawlingin conjunctiva)

How is malaria dx? Blood smear




How is malaria transmitted? mosquito (Anopheles)

How is Onchocerca volvulus


transmitted by female

blackflies; causes riverblindness

How is ParagonimusWestermani transmitted and


Undercooked crab meat;causes inflammation and

secondary bacterial infectionof the lung

How is Sporothrix schenckiiappear under the scope?

Dimorphic fugus that lives onvegetation




How is StrongyloidesStercoralis transmitted and


larvae in soil penetrate theskin; intestinal infection

How is T. Canis transmittedand what disease results?

food contaminated with eggs;

causes granulomas (if inretina=blindness)

How is T. Solium transmittedand what disease results?

undercooked pork tapeworm;causes mass lesions in the

brain, cysticercosis

How is T. Vaginalistransmitted?

sexually




How is Toxo transmitted? cysts in meat or cat feces

How is Trichinella Spiralis


undercooked meat, usually

pork; inflammation of muscle,periorbital edema

How is Wucheria transmittedand what disease results?

female mosquito; causesblockage of lymphatic vessels

(elephantiasis)

In what cells do you findhistoplasmosis?

macrophages




Is Pneumocystis Carinii ayeast?

Yes, but originally classifiedas a Protozoa

Microscopically how doesCandida appear?

budding yeast with

pseudohyphae, germ tubeformation at 37 degrees C)

Name 3 Trematodes (Flukes) .Schistosoma, Clonorchissinensis, Paragonimus

Westermani

Name 4 opportunistic fungalinfections.

Candida Albicans, Aspergillusfumigatus, CryptococcusNeoformans, Mucor and

Rhizopus species




Name 4 systemic mycoses.

Coccidiomycosis,Histoplasmosis,

Paracoccidioidomycosis,

Blastomycosis

Name two asexual sporestransmitted by inhalation.

Hisoplasmosis andCoccidiodomycosis

Name two Cestodes(Tapeworms) .

Taenia Solium, andEchinococcus Ganulosus

What agar is used to culturefor systemic mycoses?

Sabouraud's Agar




What are Conidia?asexual fungal spores (ex.

Blastoconidia, and

arthroconidia)

What are some commonCandida infections?

Thrush in Immunocompromised

pts (neonates, patients on

steroids, diabetics and AIDS

pts) , endocarditis in IV drug

users, vaginitis (high pH,

Diabetes, post-antibiotic) ,

diaper rash, disseminated

candidiasis (to any organ)

What are some infectionscaused by cryptococcus?

Cryptococcal meningitis,cryptococcosis

What are the 10 Nematodes(roundworms) we are

concerned with?

Ancylostoma duodenale

(hookworm) , AscarisLumbricoides, EnterobiusVermicularis (pinworm) ,Strongyloides stercoralis,

Trichinella Spiralis, DracunculusMedinensis, Loa loa, Onchocerca

Volvulus, Toxocara Canis,Wucheria Bancrofti




What are the 4 B's of Blastomycosis?

Big, Broad-Based, Budding

What are the diseases causedby Cryptosporidium?

Severe diarrhea in AIDS, Mild

disease (watery diarrhea) innon-HIV

What are the diseases causedby Toxoplasma?

Brain Abscess in HIV and birthdefects

What are the infectionscaused by Aspergillus?

Ear fungus, Lung cavityAspergilloma ('fungus ball') ,

invasive aspergillosis.




What can systemic mycosesmimic?

TB (granuloma formation)

What disease are caused byEntamoeba Histolytica?

Amebiasis: bloody diarrhea,

dysentery, liver abscess, RUQ pain

What disease does Mucorspecies cause?

Mucormycosis

What disease doesPneumocystis carinii cause?

Pneumocystis CariniiPneumonia




What disease does SporothrixSchenckii cause?

Sprotricosis

What disease doesTrypanosoma Cruzi casue?

Chaga's Disease (heartdisease)

What disease is caused byGiardia Lamblia?

Giardiasis: bloating,flatulence, foul-smelling

diarrhea

What disease is caused byLeishmanina donovani?

Visceral Leishmaniasis (Kala-azar)




What disease is caused by P.Carinii?

Dif use interstitial pneumoniain HIV

What disease is caused by the

plasmodium species (vivax,ovale, malariae, falciparum) ?

Malaria: cyclic fever,

headache, anemia,splenomegaly

What disease is caused byTrypanosma Gambiense and

Rhodesiense?

African Sleeping sickness

What disesase doesTrichomonas Vaginalis cause?

Vaginitis: foul-smeilling,greenish discharge; itching

and burning




What do you tx P. Cariniiwith?

TMP-SMZ, or pentamidine, ordapsone

What do you use to culturecryptococcus? Asabouraud's Agar

What do you use to DiagnoseE. Histolytica?

Serology and/or trophozoitesor cysts in stool

What do you use to stainCryptococcus?

India Ink




What do you use to txcryptosporidium?

nothing

What do you use to TxGiardiasis? Metronidazole

What do you use to tx T.Vaginalis?

Metronidazole

What do you used to dx P.Carinii?

Lung biopsy or lavage,methenamine silver stain




What do you used to TxCandida Albicans?

Nystatin for superficialinfection, Amphotericin B for

systemic

What does Alba mean? white

What does dimorphic mean?fungi that are mold in the soil(low temp) and yeast in tissue

(higher/body temp 37 C)

What is diagnositic for L.donovani?

Macrophages containgamastigotes




What is diagnositic of T.Vaginalis?

Trophozoites on wet mount

What is histoplasmosisassociated with? bird or bat droppings

What is the progression of S.Schenckii infection?

traumatic introduction intothe skin, typically by a thorn

('rose gardner's' disease) ,causes local pustule or ulcerwith nodules along draining

lymphatics (ascendinglymphangitis) . Little systemic

illness.

What is the vector for L.donovani?

Sandfly




What is the vector for T.Cruzi?

Reduviid Bug

What is the vector for T.Gambiense and Rhodesiense? Tstese fly

What is used to dx Africansleeping sickness?

Blood smear

What is used to dx T. Cruzii? blood smear




What is used to dxtoxoplasma?

serology and biopsy

What is used to treat D.Medinensis? Niridazole

What is used to Treat E.Histolytica?

Metronidazole and Iodoquinol

What is used to tx africansleeping sickness?

Suramin for bloodbornedisease or melaroprol for CNS

penetration




What is used to txAncylostoma duodenale?

Mebendazole/pyrantelpamoate

What is used to tx AscarisLumbricoides?


What is used to tx Clonorhissinensis?

Praziquantel

What is used to tx E.Granulosus?

Albendazole




What is used to tx E.Vermicularis?


What is used to tx L.Donovani? Sodium Stibogluconate

What is used to tx Loa loa? diethylcarbamazine

What is used to tx malaria?

Chloroquine ( primaquine forvivax, ovale) , sulfadoxine +pyrimethamine, mefloquine,

quinine




What is used to tx O.Volvulus?

Ivermectin

What is used to txParagonimus Wetermani? Praziquantel

What is used to tx S.Stercoralis?

Ivermectin/thiabendazole

What is used to txschistosoma?

Praziquantel




What is used to tx T. Canis? diethylcarbamazine

What is used to tx T. Cruzii? Nifurtimox

What is used to tx T. Spiralis? Thiabendazole

What is used to tx taeniasolium infection?

Praziquantel/niclosamide;albendazole for cysticercosis




What is used to txtoxoplasma?

sulfadiazine + pyrimethamine

What is used to tx W.Bancrofti? diethylcarbamazine

What patient population issusceptible to Mucor disease?

Ketoacidotic patients andLeukemic patients

What stain do you use forlung tissue when you are

detecting P. Carinii?

silver




What state predisposes you toP. Carinii infection?

Immunosuppression

What test can be used todetect polysaccharidecapsular antigen of

Cryptococcus?

latex agglutination test

What types of infections canCandida Albicans cause?

systemic or superficial fungalin fections

When do you startprophylaxis in HIV patients?

when the CD4 drops below200 cells/mL




Where do the mucor andrhizopus species fungi

proliferate?

in the walls of blood vesselsand cause infarction of distal

tissue

Where is Blastomycosisendemic?

States east of the MississippiRiver and Central America

Where is Coccidioidomycosisendemic?

SWUS, California (San JoaquinValley or destert (desert

bumps) 'Valley fever')

Where is Histoplasmosisendemic?

Mississippi and Ohio Rivervalleys




Where isParacoccioidomycosis

endemic?

Rural Latin America

All viruses are haploid except_________?(1)

Retroviruses, which have two

identical ssRNA molecules(diploid).

Bites from what 3 animals aremore prone to rabies

infection than a bite from adog?

Bat, Raccoon, and Skunk

Define complementation?

When one of 2 viruses that

infects the cell has a mutationthat results in a nonfunctional

protein. The nonmutatedvirus 'complements' the

mutated one by making afunctional protein that serves

both viruses.IVMS FLASH FACTS-USMLE Step 1 251



Define genetic drift.Minor changes based on

random mutations.

Define genetic shift.

Reassorment of viral genome(such as when human flu Avirus recombines with swin

flu A virus.)

Define phenotypic mixing?

When virus A acquires virus Bcoat proteins and acts likevirus B buts its progeny willhave virus A genome and

coat.

Define reassortment?

-When viruses withsegmented genomes (eg.influenza virus) exchange

segments. -High frequencyrecombination. Cause of worldwide pandemics.




Define recombination?

Exchange of genes between 2chromosomes by crossing

over within regions of

significant base sequencehomology.

Describe its incubation period

and whether or not it has acarrier.

-Short incubation period (3weeks) -No carriers

Describe its incubation periodand whether or not it has a

carrier.

-Long incubation (3 months)- has carriers

Describe the general conceptof bacterial super infection

which can occur withinfluenza infection?

A life-threatening illnesswhere a bacterial infection issuperimposed on an existing

viral infection.


biochem- micro -immuno-pharm flash facts

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