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Flashcards in test #36 4.27 Deck (123):
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

31

allergic triad

allergic rhinitis
asthma
atopic dermatitis

32

gluten enteropathy & dermatitis herpetiformis presentation

usually in 4th-5th decades of life. UNCOMMON in children!

pruritic vesicles & plaques on buttocks & extensor surfaces.

33

erythematous, well-demarcated papules and plaques w/ silvery scale

psoriasis

34

dermatitis herpetiformis vs. atopic dermatitis

atopic dermatitis: usu kids

dermatitis herpetiformis: usu presents in 4th-5th decade of life, uncommon in kids.

35

acute viral hepatitis on hepatocyte (2)

1. hepatocyte injury
2. hepatocyte death

36

travel to foreign country (overcrowing & poor sanitation) & return w/ liver problems

think acute hepatitis A

37

hepatocyte injury vs. hepatocyte death

injury: ballooning degeneration
- cytoplasm appears empty w/ only occasional eosinophillic organelle remnant remaining

death: lobular architecture disruption, cytolysis, apoptosis, confluent hepatocyte necrosis.

damage attracts mononuclear inflammation in sinusoids & portal tracts

38

bridging necrosis

regions of adjacent lobules are interconnected by swatches of dead hepatocytes

39

presentation of viral A hepatitis

acute.

fever, malaise, fatigue, anorexia, nausea & vomiting, mild abdominal pain.

DARK URINE = increase serum bilirubin.

hepatomegaly & jaundice

40

prolonged pruritus and fatigue suggests

primary sclerosing cholangitis (diffuse inflammation and fibrosis of biliary tract)

recall pruitus -- bile acid mediated

41

acholic stools and bone pain suggests

chronic cholestatis process, like primary biliary cirrhosis

42

liver lobule

functional anatomical unit of liver.

hexagonal structure centered on central vein

portal triad at each corner

43

liver acinus

diamond connecting 2 central veins (across) and 2 portal triads (vertically) of 2 different lobules

creates 'zones' of oxygenation

zone 1: vertical closest to 2 portal triads.
- oxygen dependent processes (gluconeogenesis, beta oxidation, cholesterol synthesis)
- site of viral hepatis

zone 3: closest to each central vein
- metabolic toxin removal (p450 system)

- site of alcoholic hepatitis

44

acute hepatitis primary affects what part of liver? chronic?

acute: lobule & portal tract

chronic: predominantly portal tract

45

formula for resistance

R = nL / r^4

n = viscosity
L = length
r = radius

46

facies of potter syndrome

suborbital creases
depressed nasal tip
low set eats
retrognathia

47

common intraabdominal infections (i.e. post perforated appendix)

usu polymicrobial:
1. b. frag
2. ecoli

most common

48

candida can be isolated from an intraabdominal infection related to.

perforation of proximal bowel, like perforated peptic ulcer

49

what does EBV bind to in order to enter cell?

CD21 on B-lymphocytes

EBV glycoprotein gp350 binds to C3d complement component receptor CD21

50

where is CD21 expressed

1. B cell surface
2. nasopharyngeal epithelial cells

51

how does parvovirus enter erythroid cells

blood group P antigen

expressed on mature erythrocytes, erythroid progenitors, megakaryoctes, palcenta, fetal liver and heart

immature erythroid cells most vulnerable (adult bone marrow & fetal liver are principle targets)

52

how does CMV bind to cells

like other herpesvirus, via glycosaminoglycans

53

how does adenovirus enter cells

rodlike structures from its penton base capsomeres mediate adsorption to host cells.

receptor: transmembrane protein member of immunoglobulin superfamily

54

kozack sequence

on mRNA
initiator for translation

gcc(A or G)ccAUGG

purine 3 bases upstream AUG = very important

55

shrine dalgarno

8bp upstream AUG

help recruit ribosome to mRNA

56

3 steps of translation (note where energy is used)

1. initiation (IF, uses GTP)
- assemble 40s subunit w/ initiator tRNA. wait for mRNA & 60s to bind

2. elongation
- charged tRNA (used ATP) binds
- ribozyme catalyzes peptidyl-transferase (no energy)
- translation of ribosome 3 nucleotides towards 3' end of mRNA (uses GTP and EF2)

3. termination, stop codon -- recognized by release factor. polypeptide released

57

what are the three end products of the nonoxidative (reversible) part of HMP shunt

1. ribose 5-phosphate
2. glyceraldehyde 3-phosphate
3. fructose 6-phoshate

58

NADPH vs. NADH

NADPH used as reducing equivalent in cytosol

NADH used as energy source for ATP synthesis (electron transport chain)

59

how can ribose be synthesized by fructose-6-phosphate or glyceraldehyde-3-phosphate

ribose 5-phosphate glyceraldehyde 3-phosphate
(via transketolase)

[simultaneously xylucose 5-phosphate sedoheptulose 7-phosphate]

glyceraldehyde 3-phosphate fructose 6-phosphate
(via transaldolase)

[simultaneously sedoheptulose 7-phosphate erythrose 4-phosphate

60

what reaction do transketolase do? transaldolase?

transketolase: transfers 2 carbon groups

transaldolase: transfers 3 carbon groups

61

which cells produce NADPH (3 main uses)

1. NADPH consumed in fatty acid & steroid synthesis.
2. cytochrome p450 pathway
3. generation of superoxide in phagocytes

so liver, adrenal cortex, gonads, adipose tissue, erythrocytes

62

making MPO in phagocytes

1. NADPH oxidase (O2-> superoxide
2. superoxide dismutase (superoxide -> hydrogen peroxide
3. myeloperoxidase (hydrogen peroxide -> MPO)

63

enolase

converts 2-phosphoglycerate -> phosphoenolpyruvate in glycolysis

64

aconitase

citrate -> isocitrate in TCA

65

green pigment in echhymoses

biliverdin

heme -> biliverdin
via HEME OXYGENASE

66

continuous leuprolide on testosterone and DHT levels

concordant transient increase, followed by decrease in both

67

B12 + R protein? B-12 + intrinsic factor

R protein protects B12 from acid in stomach (released by pancreatic enzymes

intrinsic-factor protects B12 from pancreatic proteolysis + permits absorption in terminal ileum (bind to intrinsic factor receptor

68

r protein

haptocorrin -- made in salvia
-binds B12, protects from stomach acid

degraded by pancreatic enzymes

69

most cases of B12 deficiency

unrelated to intake.. usu poor absorption.

b12 often needs to be taken parenterally

70

elderly patient w/ chronic anemia and unknown underlying cause?

prob B-12 malabsorption.

elderly:
-poor absorption due to gastric atrophy --> achlorhydia and decreased release of B12 from food proteins
- also pernicious anemia can be common in elderly
- or terminal ileal disease (IBD)
- or bacterial overgrowth syndrome

71

in what form is diet more readily absorpbed

dietary meat: iron in heme form --> more readily absorbed

iron from vegetable sources --> less absorbed

72

endocarditis

inflammation of endocardium caused by
1. infectious agents:
- s. aureus or s. viridans
2. inflammatory processes:
- rheumatic fever or SLE
3. other: metastatic cancer, carcinoid, etc

73

culture negative endocarditis

bartonella
coxiella
mycoplasma
histoplasma
chylamydia
HACEK organisms
haemophilus, actinobacillus, cardiobacterium, eikenella, kingella

74

aging heart changes

decrease in left ventricular chamber size (particular apex to base dimension)
- causes basal ventricular septum to bulge into left ventricular outflow tract: "sigmoid septum"

atrophy of cardiac myocytes
- increase interstitial connective tissue

progresive accumulation of brown cytoplasmic granules
- lipofuscin pigment: ingestible byproducts of subcellular membrane lipid peroxidation

75

cystic fibrosis fertility

male infertility -- bilateral absence of vas deferens

76

GI agents that slow gastric motility

opiates like loperamide

77

loperamide

opiod agents that slow down gastric motility (decrease volume of diarrhea, slow intestinal transit time, increase net reabsorption)

78

symptomatic rx for cystic fibrosis

1. n-acetylcysteine: cleaves disulfide bonds in glycoproteins of mucus
2. dornase alfa (DNAse) to clear leukocytic debris

79

dornase alfa

DNAse for cystic fibrosis, cleave leukocytic debris

80

prognosis of colorectal cancer related to

STAGE (spread / expansion)

not grade (differentiation)

81

most impt red cell index in hereditary spherocytosis?

INCREASED MCHC
mean corpuscular hemoglobin concentration

- indicates membrane LOSS and red cell DEHYDRATION

(as evidence by osmotic fragility test)

82

MCV in hereditary spherocytosis

LOW to normal, bc membrane loss

83

howell-jolly bodies & pappenheimer bodies

associated w/ splenectomy

howell-jolly: nuclear fragments, DNA

pappenheimer bodies: iron

84

eoisin-5-maleimide binding test

screening for hereditary spherocytosis

also see splenomegaly & increased osmotic fragility test

85

Heinz bodies

ppt hemoglobin
- oxidation of sulfhydryl groups

86

renal cell carcinoma most commonly? comes from? gross?

clear cell carcinoma

from PCT

golden-yellow: high glycogen and lipid content

usu has paraneoplastic (epo, acth, pthrp)

87

renal oncocytomas

RARE tumors originating from COLLECTING DUCT cells

not clear cell!

large, well-differentiated neoplastic cells w/ numerous mitochondria

usu no paraneoplastic

88

renal tumor from PCT? from collecting duct? renal pelvis?

PCT: clear cell carcinoma

CD: oncocytoma (rare)

pelvis: transitional cell carcinoma

89

transitional cell carcinoma

90% of tumors involving renal pelvis.

often forms papillary tumors, composed of urothelium supported by thin fibrobvascular stalk

90

prognosis of renal cell carcinoma (clear cell)

resistant to chemo and radiation, need to resect. if spread hematogenously already, which is common, it is bad.

91

wilms tumor originates from..

embryonic glomerular structure.

due to loss of function mutation in WT1 or 2 on chr. 11

92

beckwith-wierdman syndrome, or WAGR?

wilms tumor
aniridia
genitourinary malformation
mental retardation

93

2. unique feature of listera monocytogenes

facultative intracellular, able to

1. multiply at 4 degrees (cold enrichment)
2. tumbling motility

gram positive rod (distinguish from cornybacterium)

94

location of pudendal nerve block

S2-S4 nerve roots

1. sensory to perineum and genitals
2. motor to sphincter urethrae and external anal sphincter.

palpate intravaginally for ischial spines --> inject there

95

genitofermoral nerve

L1-L2
- courses anterior surface of psoas muscle
- splits into genital and femoral branches
-innervates scrotum / labia majora & cutaneously femoral triangle, respectively

96

iliohypogastric nerve

T12/L1
courses in that dermatome to innervate skin overlying iliac crests

97

lateral femoral cutaneous

L2-L3
courses deep to inguinal ligament.
innervate skin on anterolateral thigh

98

obturator n

L3-L4
motor innervation to medial thigh (adductor)

99

inferior gluteal n

L5-S2
motor innervation to gluteus maximus

100

krukenberg tumor

malignant ovarian tumor w/ mucous.

mucin-secreting signet cell adenocarcinoma

metastasis from gastric cancer / GI

101

metastasis of gastric cancer can present as.. (3)

1. virchow node
- involvement of left supraclavicular node by metastasis from stomach

2. sister mary joseph nodule
- subcutaneous periumbilical metastasis
- (seen w/ intestinal type)

3. krukenberg tumor of ovary
- bilateral metastases to ovaries. abundant mucus signet ring cells
- (seen w/ diffuse type)

102

what might decrease effectiveness of levodopa/carbidopa in parkinson's patient

B6 supplementation.

DOPA --> dopamine
via dopamine decarboxylase
cofactor: B6

this enzyme is blocked peripherally by carbidopa

103

possible side effect of cimetidine

H2 receptor blocker

can cause gynecomastia!! +

104

first recommendation for high LDL, high TG, and low HDL?

exercise and diet!!

105

rx for hypertriglyceridemia (4)

1. diet, exercise, weight loss, abstinence from smoking & alcohol

2. fibrates (PPAR-alpha & lipoproteinlipase)

3. niacin (decreasing synthesis of TG and VLDL)

4. fish oil containing omega 3-fatty acids (decreases VLDL and triglyceridesn

106

actinic keratosis

3-6mm scaly, erythematous lesions occuring on sun-exposed areas

histology:
-hyperkeratosis (hyperplasia of stratum corneum
-parakeratosis (retention of nuclei in stratum corneum)

pigment irregularities & dilated vessels bc associated w/ sun exposure!

small percentage progress to squamous cell carcinoma

107

psoriasis presentation. location histology.

usu on knees and elbows and nape

hyperkeratotic plaques

histology: clubbed rete ridges, hyperkeratosis, neutrophils in stratum corneum (monroe abscesses), and perivascular lymphocytic infiltrate

108

dermatofibroma

superficial benign fibrous histiocytoma
unknown etiology

benign proliferation of fibroblasts.
common on lower extremities as solitary nodules

109

most common skin cancer

basal cell carcinoma

110

metastasis of basal cell carcinoma? melanoma?

basal cell: low tendency to metastasize

melanoma: high tendency to metastazie

111

presentation of basal cell carcinoma

usu pearly papule w/ central depression or ulceration

histology: nests of basaloid cells and peripheral palisaiding nuclei

112

most common cause of renal papillary necrosis

diabetes mellitus

113

causes of renal papillary necrosis

SO sAAD

- sickle cell anemia / trait
obstruction of small kidney vessels, predispose to ischemia.

- obstruction
- acute pyelo
both: edematous interstitium of pyelonephritic kidney compresses medullary vasculature --> predisposing to ischemia

- analgesic: phenacetin, acetaminophen, aspirin, caffeine, codeine
inhibit renal blood flow by decreasing prostaglandins.

- diabetic mellitus
nonenzymatic glycosylation --> alter vascular walls --> compromised renal vasculature

114

abrupt onset of gross hematuria in a pt w/ family history of sickle cell suggests...

renal papillary necrosis

115

gross & microscopic renal papillary necrosis

gross: gray yellow/white necrosis of tips or distal 2/3 of renal pyramids

microscopic: coagulative infarct necrosis, preserved tubule outlines. later- -> fibrous depressions

116

condition that causes low complement levels

poststreptococcal glomerulonephritis

117

thrombin time measures

rate of conversion of fibrinogen to fibrin

prolonged by heparin and dysfibrinogenemia

118

what causes mallory-weiss tears?

longitudinal mucosal tears at esophagogastric-squamocolumnar junction.

secondary to rapid intraabdominal & intraluminal gastric pressures (retching & vomitting)

also: coughing, hiccuping

predisposing factor: hiatal hernias.

119

evidence of steroid use

suspect in athlete w/ erythrocytosis, abnormal testicular size & fxn, hepatic abnormalities, & acne

1. high hematocrit (androgen stimulate RBC production)
[reason why males have higher hematocrit]

2. small testicular size, decreased sperm production, decreased endogenous testosterone

3. acne, voice deepening, male pattern baldness

hepatic side effects

120

rx for hep C (chronic infection)

ribavarin and IFN-alpha

121

ribavarin is used for..

chronic hep C infxn
RSV

122

mechanism of ribavarin (5)

nucleoside antimetabolite.
interferences w/ duplication of viral genetic material

lethal hypermutation, inhibiting RNA pol and inosine monophosphate dehydrogenase (depleting GTP), causing defective 5' cap formation on mRNA transcrips, and modulates a more effective immune response.

1. phosphorylated, incorporated into RNA & pairs w. uracil or cytosine --> hypermutation during RNA dep RNA replication

2. direct inhibition of HCV RNA pol (by ribavarin triphosphate)

3. ribavarin monophosphate inhibits cellular monophosphate dehydrogenase (depleting GTP pools)
[needed to convert IMP to GMP)

4. inhibits viral RNA guanylyltransferase and methytransferase, resulting in defective 5' cap formation on mRNA --> ineffective translation

5. enhances Th1-cell mediated immunity while inhibiting Th2 cytokine production --> modulates a more effective immune response

123

which two drugs block IMP dehydrogenase? what step is blocked

purine de novo synthesis

IMP -> GMP

mycophenolate & ribavarin