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1

4 A's of Ataxia-telengectiasia

B & T cell immunodeficiency
autosomal recessive

- ATM gene (repair double stranded breaks)
- spider Angiomas
- IgA deficiency (bc need double stranded DNA breaks for class switching)
- increased AFP

radiation sensitivity, recurrent sinopulmonary infxn

also increased risk of hematological malignancy

2

bare lymphocyte syndrome

autosomal recessive form of SCI

immunodeficiency resulting form a defect in expression of HLA class II antigens on APC

no MHC class II to present foreign antigens to T cells & have both cell mediated & humoral response

3

how does cisplatin exert chemotherapeutic effects? how can this be prevented (2 ways)

generates reactive oxygen species that can cross-link DNA

1. amifostine = free radical scavenger. can prevent nephrotoxity and acoustic nerve damage.

2. establishing chloride diuresis (IV normal saline) bc cisplatin stays in nonreactive state when in high Cl- concentration

4

N-acetylcysteine for influenza, bronchitis, cystic fibrosis?

mucolytic agent
-cleaves DISULFIDE bones in mucous glycoproteins

also
-enhances glutathione production
-conjugates NAPQI
-prevents radiocontrast-induced nephropathy

4 main effects

5

filgrastim

G-CSF analong.

stimulate prolif and diff of granulocytes

6

fomepizole

antidote in methanol (rubbing alcohol) or ethylene glycol (antifreeze) posioning

competitive antagonist of alcohol dehydrogenase (prevents conversion into toxic metabolites)

7

methanol is in..

rubbing alcohol

8

ethylene glycol is in...

antifreeze

9

dexrazoxane

iron-chelating agent, help prevents anthracycline-induced (doxorubicin) toxicity

CHF

10

anthracycline fxn

generate free radicals --> intercalate DNA --> cause breaks

antitumor antibiotic

11

congenital hypothyroidism (cretinism)

6 P's
- pot-bellied
- pale
- puffy-faced (myxedema -- edema of skin and subcut fat)
- protruding UMBILICUS
- protuberant TONGUE
- poor brain development

mental retardation, short, coarse facial features, prolonged jaundice, hypotonic

increased incidence of congenital heart defects like ASD and VSD

12

what can cause congenital hypothyroidism (4)

-maternal hypothyroidism,
-thyroid agenesis,
-thyriod dysgenesis (most common in US
- dyshormonogenic goiter

13

4 general effects of thyroid hormones

4 B's
1. brain maturation
2. bone growth (increased osteoclast activity
3. b-adrenergic (upregulate B1 in heart)
4. increased BMR

14

phenothiazine

antipsychotic / antihistamine

block D2 receptor --> relieves inhibition --> cause hyperprolactinemia at certain doses

15

how does dopamine inhibit prolactin secretion?

binds to D2 receptor on prolactin-producing cells

16

competence defined as..

ability to understand a situation and the possible CONSEQUENCES of decisions made in a situation

17

who makes medical decisions if there is no next of kin?

judge / court will appoint a guardian to act on the patient's behalf

[hospital ethics committee makes recommendations, but cannot act]

18

describe how sunlight increases vitamin D

7-dehydrocholesterol (provitamin D3) in skin absorbs UVB --> opens up B-ring, forming previtamin D3 --> undergoes isomerization induced by heat to form vitamin D3 (cholecalciferol)

physiologically-produced D3 or plant-derived D2 undergoes the 2 hydroxylation steps

1st: cytochrome P450 enzyme 25-hydroxylase converts vitamin D into 25-hydroxyvitamin D (calcidiol)

2nd: 1-alpha-hydroxylase in kidney converts calcidiol to calcitriol (active vitamin D3)

19

how is excess 1,25-vitamin D dealt w/

kidney has enzyme 24 hydroxylase, converts 25 hydroxy-vitamin D to inactive 24,25 dihydrox vitamin D

20

vitamin D2. vitamin D3. cholecalciferol. calcidiol. calcitriol. 24,25-dihydrocholecalciferol

-vitamin D2: plant-derived
-vitamin D3: cholecalciferol; physiologically produced

-calcidiol: 25-hydroxy vitamin D
-calcitriol: 1,25-dihydroxy vitamin D

21

precision and reliability

essentially equivalent. low variability when measuring same thing.

22

PCA territory? symptoms expected?

- contralateral hemianopia w/ macular sparing
- contralateral paraesthesia & numbness: face, trunk, limbs (involvement of lateral thalamus)

-cranial nerves III and IV (midbrain)
-lateral thalamus
-medial temporal lobe
- splenium of corpus callosum
- parahippocampal gyrus
- fusiform gyrus
- occipital lobe

23

ACA covers..

-frontal: inferior and medial
-parietal: medial
- anterior 4/5 of corpus callosum
- olfactory bulb and tract
- anterior basal ganglia (caudate)
- anterior limb internal capsule

24

anterior choroidal

last branch off internal carotid before it trifurcates.

supplies posterior limb of internal capsule, optic tract, LGN, choroid plexus, uncus, hippocampus, amygdala

25

artery of percheron

branches off either right or left of PCA.

supplies bilateral thalami and dorsal midbrain

rare normal variant, seen in patients w/ bilateral thalamic or dorsal midbrain stroke

26

MCA covers

- lateral convexity of frontal, parietal, temporal lobe
- deep subcortical structures, like internal capsule, basal ganglia.

usu contralateral motor & sensory defects

27

exogenous cortisol suppresses what part of HPA axis?

all! CRH, ACTH, and cortisol

bilateral adrenal cortical atrophy

28

unilateral of adrenal cortex can result from..

adrenocortical adenoma

autonomous production of cortisol from one adrenal gland suppresses CRH, ACTH. less stimulation of the OTHER gland.

29

triggers for atopic dermatitis? presentation in young children? older children

chronic inflammatory skin disorder. HALLMARK: intense pruritus (if not itching, not AD)

CHILDREN!

triggered by:
environmental antigens
- FOOD, irritants

usu present by 5 y/o:
red, weeping/crusted lesions involving face, scalp, extensor surfaces. diaper area usu spared.

older:
manifests as lichenification in flexural distribution (neck, wrists, antecubital, popliteal fossa)

30

cause of atopic dermatitis

mutations affecting proteins like filaggrin or other components of epidermis (impairment of skin's barrier function)

--> increases immunologic exposure to environmental allergens & microbial antigens --> immune HSR.

patients have:
1. high serum levels of IgE,
2. peripheral eosinophilia,
3. high cAMP phosphodiesterase in leukocytes