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Flashcards in Micro Deck (32):
1

8 year old boy presents w/
-behavioral changes, mild intellectual deterioration, and laziness
-develops progressive clumsiness and frequent involuntary jerky movements
-CSF shows increased IgG
-he dies 2 years later

Dx?
Infection d/t?

Subacute sclerosing panencephalitis (SSPE)

infection: measles
-nml infected by age 2 but takes about 6 years for symptoms to occur

2

Pt presents w/
-raised lesions on finger and toes
-white spots on retina surrounded by hemorrhage
-small non-tender, painless, erythematous lesions on palm or sole
-clots under fingernails
-new onset heart murmur
-fever

Dx
Cause
Staining

Subacute bacterial endocarditis
-osler nodes
-roth spots
-janeway lesions
-splinter hemorrhages

Causes:
-strep viridans : gram positive cocci in chains
-staph aureus: gram positive cocci in clusters

3

Pt presents w/
-pain that is relieved when leaning forward and worsens w/ inspiration
-scratchy leathery sound upon auscultation
-admitted to having flu-like illness about 2 weeks ago

Dx
EKG findings
MC cause

Dx: pericarditis (friction rub)

EKG: diffuse ST segment elevations and depression of PR

Cause:
-coxsackie B is MC
*picornavirus: positive, single stranded, naked, icosahedral, RNA virus

4

What lab test help determine MAC from TB in AIDs pt?

MAC presents w/
-anemia
-elevated alk phos
-elevated lactate dehydrogenase

5

S. Pyogenes toxic shock like syndrome vs s aureus toxic shock like syndrome

S pyogenes: release of exotoxin A causes activation fo T cells
-shock, fever, multi-organ failure
-painful, pre-existing skin infections and positive blood cultures

S. Aureus
-no pre-existing skin infections
-negative blood cultures

6

Causes endocarditis in pts w/ carcinoma of colon or pre-existing valvular lesions

Dx
Tx

Strep bovis

Tx: penicillin and ceftriaxone
-vanco for beta-lactam allergery

7

What 5 pathogens cause pharyngitis?

GrACED
-group A strep
-adenovirus
-coxsackie A
-EBV
-corynebacterium dipthetheriae

8

Mycoplasma pneumonia tx and MOA

Macrolide = 23s ribosomal RNA inhibitor

9

3 stages of bordetella pertussis

Catarrhal stage: 1-2 wks
-URI: fever, nasal congestion, rhinorrhea

Paroxysmal stage: 2-8 wks
-paroxysmal coughing followed by inspiratory whoop

Convalescent stage: wks-months
-subsiding cough

10

Types of E coli (who they infect / s/s)
-ETEC
-EIEC
-EPEC
-EHEC

ETEC = T: traveler diarrhea
-non inflammatory diarrhea d/t LT (AC) and ST (GC)

EIEC = I: inflammatory diarrhea
-bloody diarrhea d/t actin formation

EPEC = P: pediatric diarrhea
-non inflammatory d/t adherence of M cells on brush border

EHEC = H: Hamburger
-bloody diarrhea, nonfermentor of sorbitol d/t verotoxin (shigella like toxin) -> lead to HUS and hemorrhagic colitis

11

Which two microbacteria inhibit ptn synthesis by ADP-ribosylation of eER-2

Pseudomas = ecythyma gangrenosum

Diptheria = heart and nerve

12

Elementary bodies vs reticulate bodies

Chlamydia

-elementary: extracellular, inert, transmission form
-reticulate: intracellular, replicating form

13

Thin/gray malodorous discharge from vagina vs thin frothy yellow green

Gray: Gardnerella

Yellow/green: trichomonas

14

Pt presents w/ progressive weakness of his legs and arms
-has noticed it since childhood: no vaccination history available
-shows: flaccid paralysis, ms atrophy, fasciculations, areflexia

Dx
Where is the lesion

Polio -> poliovirus (+, single stranded RNA, picornavirus)

Attacks ventral horn -> LMN

15

Pt presents w/
-loss of conscious proprioception and vibration sensation
-areflexia
-pain, temp and ms strength are preserved
-sexually active w/ multiple partners

Dx
Where is the lesion

Tabes dorsalis -> tertiary syphillis

Dorsal columns affected

16

HIV Pt presents with
-CD4 count of 150
-weakness, disturbance of speech, congnitive abnml, HA, gait disorder, visual impairment and sensory loss
-MRI: shows multiple non enhancing multifocal white matter lesions

Dx
Infectious agent

Dx: progressive multifocal leukoencephalopathy
-circle, double stranded, naked, DNA virus
-CD4 <200

Infectious agent: JC virus -> destruction of myelinating oligodendrocytes

17

42 year old man returning from vacation in Honduras presents w/
-grandmal seizure accompanied by HA, n/v, and some visual changes
-CT of the brain shows multiple punctate calcifications and two cystic lesions with surrounding edema (swiss cheese)
-tx is began w/ albendazole and praziquantel

Dx
Infectious agent
How did the patient occur this condition

Dx: neurocysticercosis

Infectious agent: taenia solium (tapeworm/cestode)

Acquired infection via: ingestion of eggs (feces contaminated water) or autoinfection (perianal area -> mouth via contaminated fingers)
-oncosphere crosses the intestinal wall -> enters circulation -> gains access to tissues

18

54 year old pt from Ecuador comes in complaining of
-recurrent HA, n, fatigue, nuchal rigidity for the past year
-CSF shows: increased lymphocytes, plasma cells, macrophages, and fibroblast ; ptn and pressure are also elevated while glucose in decreased

Dx
MC cause

Dx: chronic meningitis

Cause: Mycobacterium tuberculosis
-others: syphilis, brucellosis, fungal infection

19

CSF fluid in pts w/
-bacterial (purulent)
-aseptic (viral)
-granulomatous (fungal)

*cells, glucose, ptns, and pressure levels

Bacterial: increased neutrophils, ptns, and pressure; decreased glucose

Viral: increased lymphocytes, ptn erythrocytes, nml glucose, and pressure

Granulomatous: increased all cell types, decreased glucose, increased ptn and pressure

20

33 year old man with AIDs develops multifocal encephalitis
-u/l, vesicular, painful rash on the left side of his back, mid chest, left side of chest and upper abdomen that appeared one month ago
-tx w/ acyclovir began but he died 4 days later

Dx
Infectious agent

Herpes zoster encephalitis

Infectious agent: varciella zoster virus
-d/t its reactivation (rash)

21

Multinucleated giant cells w/ intranuclear inclusion bodies seen in patients w/ encephalitis

Infectious agent

Herpes simplex virus

22

-MC cause of sporadic encephalitis in US
-CSF: elevated ptn, lymphocytes, erythrocytes and nml glucose
-MRI: u/l temporal lobe hypointense lesions

Dx
Tx
What would be seen on microscopic exam of the brain
What might be seen on ocular exam

HSV-1 encephalitis
Tx: acyclovir
Brain: cowdry type A inclusions: intranuclear viral inclusion bodies
Ocular: serpignous (snake-like) corneal ulcers

23

Toxoplasma IgG vs IgM antibodies

IgG: have been infected with it but no s/s
IgM: active infection

24

What are the 3 most common neonatal pathogens associated with meningitis

Group B strep

E coli

Listeria monocytogenes

25

What are the 2 MC causes of botulism toxicity in adults

-canned alkaline vegetables
-preserved fish

*both have preformed toxins

26

In HIV positive pts what is the most common cause of a ring-enhancing brain lesion?
-what would you see on biopsy?
-what cell type would be deficient

Toxoplasmosis

Biopsy: crescentic microorganisms and necrosis

Th-1 helper cells would be deficient d/t cell-mediated immune response
- intracellular organism

27

Pt presents w/
-excitability, agitation, hypersalivation, sweating, pupillary dilation
-hydrophobia, aerophobia (pharyngeal spasm triggered by air drafts)
-facial ms spasticity

Pt is diagnosed with rabies
-what would you see on histology ?

Negri bodies: elongated eosinophilic intracytoplasmic inclusions w/in the pyramidal neurons of the hippocampus and purkinje neurons of cerebellum

28

Elderly pt presents w/
-urinary incontinence
-new onset confusion
-gait disturbances

Dx
-what would be seen on CT and CSF
- tx

nml pressure hydrocephalus: “wet, wacky, and wobbly”

-CT: dilated ventricles
-CSF: nml pressure

Tx: ventricular shunt

29

MC cause of meningitis in AIDs pts
-how to dx it

Cryptococcus neoformans
-dx: latex particle agglutination (india ink misses 50%)

30

Pt presents w/
- facial rash (in children)
- arthropathy : acts like RA but remits in 7 days

Parvovirus B19

31

Pt presents w/
- aphasia, hemiparesis, cortical blindness, ataxia, homonymous. Hemianopia
- MRI: abnml T2 signal in white matter
- electroencephalogram: slowing over both cerebral hemispheres
- biopsy: demyelination w/ abnml giant oligodendrocytes that contain eosinophilic intranuclear inclusions

Dx
Infectious agent
What pt condition occurs most commonly in assoc w/ this disease
Treatment

Progressive multifocal leukoencephalopathy

JC virus

AIDs patients

Not effective treatment

32

Pt w/
- bloody diarrhea
- weakness in legs that is ascending
- CSF: increased ptn but nml cell counts

Dx
What cell is involved in dz process

Guillain barre syndrome
- campylobacter jejuni

Schwann cell