Day 4.3 Micro Flashcards
Know how to label brain stem/nerves p411
.
What does the pineal gland do?
secretes melatonin (lack of light –> SCN –> pineal –>melatonin) to regulate circadian rhythm
Superior and inferior colliculi
Superior - conjugate vertical gaze center
Inferior - hearing
eyes above ears
Parinaud syndrome
paralysis of conjugate vertical gaze d/t lesion in superior colliculi (e.g. pinealoma)
Pituitary adenoma effect on vision
Can compress optic chiasm and cause bitemporal hemianopsia (loss of vision in half of each eye, on the outside of each eye (can still see through inner half of each)
What kind of cells have horseshoe pattern of nuclei?
Giant cells
e.g. Langerhans giant cell of Mycobacterium TB
What are “red snappers” histologically?
Mycobacterium TB organisms stain red with acid-fast staining.
Ghon focus vs Ghon complex
Ghon focus - calcified scar (usu lower lobes)
Ghon complex - focus + hilar lymphadenopathy or calcification.
These are both from primary TB. They are NOT caseating. Caseating stuff is secondary TB (reactivation, reinfection)
Mycobacterium kansasii esp affects which pts
Causes pulmonary TB-like sympt, esp in chronic bronchitis or emphysema pts (COPD pts)
Dx’g TB
Culture on Lowenstein-Jensen agar, but takes 2-4 wks bc v slow-growing.
In the meantime, take early morning sputum 3 days in a row and acid-fast stain it.
Mycobacterium scrolfaceum
Causes cervical lymphadenitis in kids
Mycobacterium marinum
Aquatic-assocd- in boaters, shipyard workers, aquarium owners
Usu superficial skin lesion, but can cause osteomyelitis, arthritis.
Why do pts with leprosy injure their hands and feet?
Mycobacterium leprae (Hansen’s dz) infects the superficial nerves- so pt loses sensation. Loss of sensation means injury is common (w/o realizing it)
Which kind of leprosy is communicable (contagious)?
Leprotamous. Presents diffusely over skin.
vs Tuberculoid, which is limited to nodules
What pts get toxicity to dapsone (leprosy drug)
Causes hemolysis esp in G6PD-deficient pts, bc they are sensitive to oxidizing drugs.
Can use rifampin + clofazimine + dapsone instead.
Dapsone is used to treat…
Leprosy (M. leprae)
PCP pneumonia
Water contaminated w animal urine
Leptospira
Hanta virus - assoc w rat/mouse urine
What is a unique feature of leptospira px?
Jaundice.
Otherwise causes flulike sympt like everything else. Not many infections cause jaundice.
What is azotemia?
Increased BUN and increased creatinine, indicating kidney dysfn. Seen in Weil’s dz (ictohemorrhagic leptospirosis)
What is tree-barking of the aorta?
Aortitis- severe inflammation/disfigurement of the aorta, due to destruction of vaso vasorum (sml arteries supplying aorta)
seen in tertiary (3) syphilis
Diseases w rash on palms and soles
Secondary(2) syphilis
Rocky Mtn Spotted Fever
Cocksackie A virus
Stg 2 Lyme dz sympt
Neurologic- Bell’s palsy (can be bilateral or unilateral). Meningitis, peripheral neuropathy, ridiculopathy (referred pain).
Cardiac- AV nodal block, myopericarditis
What are keloids?
Scar w excess collagen
Seen in Yaws (Treponema pertenue)
Yaws
caused by Treponema pertenue
infection of skin, bone, joint –> healing w keloids –> severe limb deformities and facial deformities, esp destruction of nasal bones and cartilage.
VDRL+ (but not an STD)
Tabes dorsalis
Degeneration of dorsal columns and dorsal roots d/t (3)Tertiary syphilis. These carry sensation and esp proprioception.
Get broad-based ataxia- wide gait bc can’t tell where legs are
+romberg sign
What does “pupil constricts w accommodation” mean?
Take finger and bring it to nose- pupil will constrict as eyes watch finger. (Accommodation is watching something get closer)
Seen in argyll-robertson pupil (3 syphilis)
Romberg test
Stand w feet together, arms out, eyes closed.
To know where you are in space, you have 3 things:
1. vision
2. proprioception
3. vestibular apparatus
You need at least 2 of these to not fall down.
Romberg takes away vision, so if you are missing one of the other ones (either proprioception or your vestibular apparatus) you will fall.
Tabes dorsalis of syphilis - no proprioception bc dorsal columns have degenerated, so you fall.
(Arms out is just to know which direction pt will fall in)
Cause of Charcot’s joints
Previously: tertiary syphilis. now, don’t have so much tertiary, so the cause is diabetic neuropathy
Saber shins
anterior bowing of tibia
seen in late congenital syphilis
Hutchison’s teeth
Notching of upper incisors
seen in late congenital syphilis
Saddle nose
flatend bridge of nose
seen in late congenital syphilis
Snuffles
blood tinged nasal secretions
seen in infants w EARLY congenital syphilis- good warning sign
Test for syphilis
Screen: VRDL
Confirm: FTA-ABS (more specific for treponemes)
If if pt is allergic to penicillin G, how to treat for syphilis?
doxycycline
Rx for bacterial vaginosis
Metronidazole (cream, gel, or oral)
Peeling of palms and soles
Rocky Mtn Spotted Fever (rickettsia)
Acrodynia (mercury poisoning)
Kawasaki
Which Rickettsial organism does not have a positive Weil-Felix?
Coxiella burnetti (Q fever) So when it's mixed w Proteus Ag, antirickettsial Ab do NOT cross-react and agglutinate.
What is Q fever?
Fever + interstitial pneumonia, caused by Coxiella burnetti (a Rickettsial organism)
What is the treatment for all Rickettsial dz?
Doxycycline
not tetra- that was a FA typo
What causes atypical pneumonia?
aka interstitial pneumonia, walking pneumonia
Legionella pneumophillia
Chlamydia pneumonia
Mycoplasma pneumonia (most common)
Also, viruses (RSV, adenovirus)
What types of Chlamydia look like gonorrhea?
Types D-K Urethritis/PID Ectopic prego (d/t fallopean tube scarring) Neonatal pneumonia Neonatal conjunctivits
Chlamydia types L1, L2, L3
Cause lymphogranuloma venereum (acute lymphadenitis)
Cause primary ulcers (ulcerative dz)
Can cause inguinal lymphadenitis for 2-6 weeks.
Can also cause rectal dz which is often mistaken for IBD (ulcerative colitis, crohns)
Prevention of chlamydia through vertical transmission
Erythromycin eye drops for all newborns in case of subacute/subclincial chlamydia or gonorrhea
Where do frequent outbreaks of Mycoplasma pneumonia occur?
Anywhere ppl <30yo are in groups
soldiers, prison, camp, bus, dorm
Rx for mycoplasma pneumonia
Tetracycline or erythromycin
Azithromycin (Z-pack)
How is Coxiella burnetti transmitted?
Aerosol (only rickettsial org that can survive outside body- due to spores)
Rickettsial triad of symptoms
Headache
Fever
Rash (vasculitis)
Alcoholic vom’d and now has foul-smelling sputum. What caused it?
Aspiration pneumonia is from: Klebsiella pneumonia or anaerobic pneumonia (Rickettsial, Chlamyidia, Legionnaire)
Rx for Mycoplasma pneumonia
Macrolides (erythromycin)
Tetracyclines
Rx for Rocky Mountain Spotted Fever
Doxycycline
Prophylaxis for Mycobacterium TB
Isoniazid
Rx for M. TB
RIPE: Rifampin Isoniazid Pyrazinamide Ethambutol \+Pyrrizodine to prevent isonizid toxicity \+Streptomycin (Cyclosterine is 2nd line therapy)
Side effects of Ethambutol
Ethambutol = Eyes
Optic neuropathy (red-green color blindness)
Can also have decreased visual acuity as well.
These are reversible.
When are HIV+ pts given azithromycin, and why?
CD4 <100
To prevent M. avium-intracellulare (complex)
Which TB drug causes drug-induced SLE?
Isoniazid
Drug-induced SLE = anti-histone Ab
Which TB drug is used to treat leprosy?
Rifampin
+dapsone +clofazimine
Rifampin enhances the metabolism of which drugs?
Rifampin increases microsomal P-450,
so drugs like birth control or warfarin
May need to increase dosage since they will be metabolized faster.
Mech of action of Pyrazinimide
effect in the acidic pH of phagolysosomes, where TB is engulfed by phagocytes
Mech of action of Ethambutol
works against polymerization of the mycobacterium cell wall by blocking arabinosyl transferase
When is Rifampin used as prophylaxis?
For meningiococcal meningitis, H. influenza B meningitis
used in close contacts
Rx for Hx of recurrent UTIs
all of these can be used long-term: TMP-SMX nitrofurantoin amoxicillin ceflexin
What drug do you give HIV+ pts when CD4 is <100?
<100: Azithromycin to prevent M. avium-intracelluaire
How does alcohol use affect Cyt P-450?
Acute alch inhibits P-450
Chronic alch induces P-450
Cytochrome P450 inducers
Queen Barb Steals Phen-phen and Refuses Greasy Carbs Chronically: Quinidine Barbituates (anticonvulsant) St. John's Wort Phenytoin (neuroleptic) Rifampin Griseofulvin (antifungal) Carbamazepine (anticonvulsant/mood stblz) Chronical alch use
Cytochrome P450 inhibitors
Acutely Inhibit from PICK EGS: Protease inhibitors Isoniazid Cimetidine Ketoconazole Erythromycin Grapefruit juice Sulfonamides \+acute alch abuse
Lupus-inducing drugs
SHIPP: Sufonamides Hydralazine (anti-HTN) Isoniazid Phenytoin (neuroleptic) Procainamide (ant-arrhythmic)
Use for macrolides
PUS:
P = Pneumonias (atypical): Chlamydia pneum, Legionella pneumophilia, Mycoplasma pneum
U = URIs. covers gram+ like Strep throat (S. pyogenes)
S = STDs. Chlamydia, gonorrhea
How does disulfiram work?
Inhibits acetaldehyde dehydrogenase, so when you drink, alcohol is not metabolized all the way to acetate like usual. It stops at an intermediate form (acetaldehyde) which makes you have asian glow.
Caused by disulfiram, metronidazole, some cephalosporins, procarbazine (chemo), 1st gen sufonylureas
Drugs w photosensitivity rxns?
SAT for a photo:
Sulfonamides
Amiodarone (anti-arrh)
Tetracyclines
Prophylaxis for PCP pneumonia
TMP-SMX
can use aerosolized pentamidine or dapsone if allergic to sulfa)
