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T1 - Phase 1 - Integrated (I) > CS&B - Clinical Correlations (I) > Flashcards

CS&B - Clinical Correlations (I) Flashcards

1
Q

A deficiency of what enzyme will lead to types A and B Niemann-Pick disease?

A

Acid sphingomyelinase

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2
Q

What substance builds up in Niemann-Pick disease types A and B?

This results in what type of cell?

A

Sphingomyelin;

foam cells

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3
Q

In what organ systems are foam cells found in cases of Niemann-Pick disease?

A

The spleen, liver, and CNS

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4
Q

What disease is characterized by acid sphingomyelinase defects and associated foam cell deposits in the CNS, spleen, and liver?

A

Niemann-Pick disease types A and B

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5
Q

Cytokine-related overactivation of what enzyme may contribute to development of multiple sclerosis?

A

Acid sphingomyelinase

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6
Q

Defects in acid sphingomyelinase lead to what disease?

Overactivation of acid sphingomyelinase may lead to what disease?

A

Niemann-Pick disease (types A and B);

multiple sclerosis

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7
Q

What effect does excess sphingomyelin have on erythrocytes?

This is commonly seen in what disease?

A

Acanthocytosis;

abetalipoproteinemia

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8
Q

What is a hematologic result of abetalipoproteinemia?

This is due to an excess of what lipid?

A

Acanthocytosis;

sphingomyelin

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9
Q

How does abetalipoproteinemia appear on a peripheral smear?

This is due to a defect involving what substance?

A

Acanthocytosis;

sphingomyelin (on the RBC E-face)

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10
Q

Cystic fibrosis involves transport of what ion into the mucus?

A

Chloride

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11
Q

What are the three main organs affected by cystic fibrosis?

A

Lungs, pancreas, liver

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12
Q

Absence of chloride movement in cystic fibrosis leads to what effect on the mucus?

A

Less H2O movement –> thick, dry mucus

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13
Q

Cystic fibrosis results as a genetic mutation in which channel?

The gene for this channel is found on which chromosome?

A

The CFTR

(cystic fibrosis transmembrane regulator);

7

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14
Q

A young child presents with progressive muscle weakness and new cardiac arrythmias. You suspect myotonic dystrophy.

What genetic results would confirm your suspicions?

A

CTG repeats

(in the DMPK gene on chromosome 19)

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15
Q

A man presents with microcephaly, cognitive deficits, indistinct philtrum, epicanthal folds, a low nasal bridge, and a short nose.

What do you suspect?

What cellular mechanism caused the issue?

A

Fetal alcohol syndrome;

impaired lipid rafts and signaling proteins

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16
Q

What effect does phalloidin (found in death cap mushrooms) have on cellular structures?

(What is the primary clinical presentation)

A

Stabilizes F-actin (prevents its degradation)

(acute, extreme hunger due to liver necrosis)

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17
Q

Cytochalasins mess with microfilaments and cause what outcome?

A

Apoptosis

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18
Q

Hereditary spherocytosis is caused by a deficiency of what protein(s)?

A

Spectrin, ankyrin, or band-3 proteins

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19
Q

Primary ciliary dyskinesia (immotile cilia syndrome) is an autosomal recessive disease known by what other name and caused by a defect in the gene coding for what protein?

A

Kartagener’s syndrome;

axonemal dynein

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20
Q

How does Kartagener’s syndrome present?

A

Chronic respiratory infections, situs inversus, infertility

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21
Q

With what cytoskeletal element does colchicine interact? How?

With what cytoskeletal element do vincristine and vinblastine interact? How?

With what cytoskeletal element does paclitaxel interact? How?

A

Microtubules, inhibits polymerization;

microtubules, inhibits polymerization;

microtubules, inhibits depolymerization

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22
Q

What stain would be most useful in diagnosing the most common type of primary brain tumor?

A

GFAP

(astrocytomas)

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23
Q

A two-year-old female toddler presents with steady loss of cognitive ability. Her father notes that she seemed cognitively normal and met all her milestones up until she was 18 mo. of age. You notice her near constant hand wringing.

What is the likely diagnosis?

A

Rett syndrome

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24
Q

What biochemical defect can lead to Rett’s syndrome?

A

Mutations in MECP2

(this HDAC-recruiting protein -MECP2- is no longer available upon histone methylation);

leading to inappropriate gene expression

(manifesting clinically as cognitive decline and persistent hand wringing)

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25
Q

Mutation in the MECP2 gene has what effect?

What is this condition called?

A

A lack of MECP2 protein –> inability to recruit HDAC –> inability to condense DNA –> excessive gene expression;

Rett’s syndrome

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26
Q

How does Rett syndrome typically present in the clinic?

A

Cognitive decline

(after ~18 mo. of seemingly normal childhood development);

hand wringing

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27
Q

An embryo is missing one autosomal chromosome. What will the result be?

A

This is a lethal mutation

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28
Q

An embryo is missing one chromosome and is 45,XO. What will the result be?

A

Turner’s syndrome

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29
Q

What are some clinical presentations of Turner’s syndrome?

A

Webbed neck,

widely spaced nipples,

swollen hands and feet,

short stature,

widespread nevi

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30
Q

Are individuals with Turner’s syndrome female or male?

A

Female

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31
Q

What is the most common human trisomy?

How does it present?

A

Trisomy 16;

it is lethal

(fetal death in the first trimester)

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32
Q

What is the most common birth defect?

How does it present?

A

Trisomy 21;

Down syndrome

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33
Q

What is unique about the 21st chromosome?

A

It is the smallest autosome

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34
Q

Do viable (non-lethal) trisomies usually happen in large or small autosomal chromosomes?

A

Small

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35
Q

Patau’s syndrome is caused by what defect?

A

Trisomy 13

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36
Q

Edward’s syndrome is caused by what defect?

A

Trisomy 18

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37
Q

Trisomy of what chromosome in particular leads to fetal death in the first trimester?

A

Trisomy 16

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38
Q

Trisomy 16 is incompatible with life and results in fetal death at what point?

A

The first trimester

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39
Q

The sphingomyelin affected in abetalipoproteinemia is found in which leaflet of the plasma membrane?

A

The E-face

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40
Q

Defects in occludins may result in severe neurological disorders do to disruption of what structure(s)?

A

The fetal blood-brain barrier (tight junctions disrupted)

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41
Q

Loss of expression of what protein can disrupt the zona adherens and lead to increased malignancy and invasiveness of a developing carcinoma?

A

E-cadherins

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42
Q

Autoimmunity against the protein desmoglein I can lead to skin disorders characterized by reduced intercellular cohesion of what in particular?

This is due to disruption of what epithelial cell junction?

A

Epidermal cells

Macula adherens (desmosome)

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43
Q

Mutations of what protein are related to types of epidermolysis bullosa (blistering skin lesions)?

This is due to disruption of what?

A

Keratins 5 and 14;

hemidesmosomes

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44
Q

Mutations in various connexin genes have been linked to what issues?

This is due to a defect in what type of cell junction?

A

Peripheral neuropathy and deafness

(both in very specific situations, not just any PN and deafness);

gap junctions

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45
Q

What pathogens act on proteins of the zona occludens to make cell junctions more permeable?

A

Cholera toxin;

CMV

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46
Q

Cholera toxins and CMV both act on what structure to increase permeability between cells?

A

The zona occludens

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47
Q

What disease is characterized by antibody attacks on proteins of the hemidesmosome?

What disease is characterized by antibody attacks on the desmosome (specifically desmoglein I and III)?

A

Bullous pemphigoid;

pemphigus vulgaris

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48
Q

Antibody attacks on what might cause bullous pemphigoid?

A

Hemidesmosome proteins

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49
Q

Antibody attacks on what might cause pemphigus vulgaris?

A

Proteins of the desmosome

(e.g. desmoglein I and III)

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50
Q

Define aneusomy.

What are the three types?

A

Aberrant number of chromosomes (due to loss or addition);

nullisomy, monosomy, trisomy

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51
Q

Define euploidy.

A

Correct number of chromosome pairs

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52
Q

What is the term if an embryo is missing both chromosomes of one chromosomal pair?

What is the term if an embryo is missing one chromosome of a chromosomal pair?

What is the term if an embryo has both chromosomes of one chromosomal pair?

What is the term if an embryo has an extra chromosome in addition to one chromosomal pair?

A

Nullisomy (-2);

monosomy (-1);

eusomy (-0; just right);

trisomy (+1);

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53
Q

What will happen to an embryo with nullisomy of any chromosomal pair?

A

Embryonic death

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54
Q

What will happen to an embryo with monosomy of any autosomal chromosome pair?

A

Embryonic death

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55
Q

What is the only survivable true monosomy?

A

Turner’s syndrome

(any other survivable monosomy is only a partial deletion of a chromosome)

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56
Q

What is the term if an embryo has three entire, homologous sets of chromosomes?

What is the term if an embryo has four entire, homologous sets of chromosomes?

A

Triploidy;

tetraploidy

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57
Q

Which usually presents earlier in life, aneuploidy or chromatin remodeling abnormalities?

A

Aneuploidy

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58
Q

What is the typical treatment for Turner’s syndrome?

To address what issues?

A

Hormonal therapy (GH and estrogen);

the slow growth and lack of sexual development

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59
Q

True/false.

Trisomies of the sex chromosomes (e.g. XXX, XXY, XYY) are all typically associated with only minor problems and a full life span.

A

True

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60
Q

Which type of autosomal trisomy is most likely to result in a viable fetus?

A

Those of small autosomes (e.g. 13, 18, 21)

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61
Q

What is the most common human trisomy?

How does it present?

A

Chromosome 16;

fetal death in the first trimester

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62
Q

Describe the typical clinical presentation of Rett syndrome.

A

Normal development during first 18 months of life

Temporary stagnation

Neurodegenerative

Loss of communication skills

Constant hand-wringing

Loss of purposeful hand function

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63
Q

How does Rett syndrome present in males?

A

Embryonic death

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64
Q

Why is Rett syndrome extremely rare in viable males?

A

The MECP2 gene is on the X chromosome, so it is normally lethal in males (who only have one X chromosome)

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65
Q

The MECP2 gene is found on which chromosome?

A

The X chromosome

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66
Q

A tall patient with tapering fingers presents to the clinic with visual problems related to subluxation of the lens of his right eye. Three days later, he dies of a cardiovascular event.

What disorder does the patient have, and what causes it?

Of what CV event did he likely die?

A

Marfan’s syndrome, fibrillin-1 defect (a scaffold for tropo-elastin);

aortic dissection

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67
Q

A teenager presents to the clinic with hyperextensible joints and skin. You notice in his history that he has been diagnosed with a murmur of one of his heart valves in the past. The patient appears well and normal for age.

What is a likely diagnosis for this patient?

What protein is likely not being produced properly?

A

Ehlers-Danlos syndrome;

collagen

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68
Q

In what layer of the skin are skin cancers most likely to originate?

A

The stratum basale of the epidermis

(e.g. basal cell carcinomas and melanomas)

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69
Q

A defect in the anchoring fibrils that connect the epidermis to the dermis can result in what condition involving blistering and skin erosion?

A

Epidermolysis bullosa

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70
Q

What are the two primary causes of albinism?

A

A defect/deficiency in tyrosinase;

a decreased melanin production rate

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71
Q

Why is the subcutaneous layer of tissue such a useful location for drug administration?

A

It is highly vascular

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72
Q

What is the term for the layers and sections of fat of the subcutaneous (hypodermic) layer?

What is the layer of striated muscle deep to the subcutaneous tissue?

A

The panniculus adiposus;

the panniculus carnasus

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73
Q

What substance binds keratin together to create the waterproofing of the skin?

Lack of this substance results in what?

A

Filaggrin;

ichthyosis

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74
Q

Filaggrin defect/deficiency leads to what immediate effect in the skin and what compensatory effect?

What is this condition called?

A

Dehydration/scaly skin, hyperkeratosis;

ichthyosis

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75
Q

What blistering condition results from defects in anchoring proteins (e.g. hemidesmosomes)

What blistering condition results as an autoimmune attack on desmosomes (specifically, desmoglein I and III)?

A

Epidermolysis bullosa;

pemphigus vulgaris

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76
Q

What disease is demonstrated here?

How is this disease classified?

A

Pemphigus vulgaris;

autoimmune (against desmoglein I, III)

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77
Q

What disease is demonstrated here?

How is this disease classified?

A

Epidermolysis bullosa;

genetic (hemidesmosome defect)

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78
Q

What disease is demonstrated here?

A

Psoriasis

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79
Q

What type of skin condition results in universally loose fragile skin? Due to a defect in what?

What type of skin condition results in universally impaired elastic recoil? Due to a defect in what?

A

Ehlers-Danlos, collagen fibers

cutis laxa, elastic fibers

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80
Q

Cutis laxa results because of a defect in what protein?

Ehlers-Danlos results because of a defect in what protein?

A

Elastic fibers;

collagen fibers

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81
Q

Cri-du-Chat syndrome is a microdeletion of the short arm of chromosome __.

A

5

82
Q

A carrier of a Robertsonian translocation has how many chromosomes?

A

45

83
Q

What is another name for DiGeorge syndrome?

It is due to a deletion of what genetic sequence?

A

Velocardiofacial syndrome;

22q11

84
Q

What rare type of skin cancer spreads quickly and deeper than BCC, SCC, and melanoma?

A

Merkel cell carcinomas

85
Q

List the types of skin cancer from most to least common.

A

Basal cell carc. > squamous cell carc. >> melanoma

>>>> anything else

86
Q

What is the most common type of cancer worldwide?

A

Skin cancer

87
Q

Genetic defect of hemidesmosomes causes:

Autoantibodies against hemidesmosomes causes:

Autoantibodies against desmosomes causes:

A

Epidermolysis bullosa;

bullous pemphigoid;

pemphigus vulgaris

88
Q

Why is acne typically associated with adolescents?

A

Sebaceous gland activity increases in adolescence

89
Q

Acne is caused by what?

A

Plugged hair follicles and their associated sebaceous glands

90
Q

What wide-spectrum antibiotic is a bacterial topoisomerase inhibitor?

A

Ciprofloxacin

91
Q

What is ciprofloxacin?

How does it exert its effect?

A

A wide-spectrum antibiotic;

inhibiting bacterial topoisomerase

92
Q

What two eukaryotic topoisomerase inhibitors can be used to treat some colon and ovarian cancers?

Which topoisomerase do they inhibit?

A

Irinotecan and Topotecan;

type I

93
Q

What are Irinotecan and Topotecan?

How do they exert their effect?

A

Chemotherapeutic agents;

type I topoisomerase inhibition

94
Q

What are Doxorubicin (adriamycin), etoposide, and ellipticine?

How do they exert their effects?

A

Chemotherapeutic agents;

type II topoisomerase inhibitors

95
Q

What wide-spectrum antibiotic is a bacterial topoisomerase inhibitor?

What are two chemotherapeutic agents that are type I topoisomerase inhibitors?

What are three chemotherapeutic agents that are type II topoisomerase inhibitors?

A

Ciprofloxacin;

Irinotecan, Topotecan;

Doxorubicin (adriamycin), etoposide, and ellipticine

96
Q

By which types of UV ray are we most at-risk of being harmed?

Which UV ray is blocked by the ozone?

A

UVA, UVB;

UVC

97
Q

What type of DNA mutation is often caused by UV rays?

A

Thymidine dimers

98
Q

What is the underlying defect in xeroderma pigmentosum?

What is its inheiritance pattern?

A

A defect in nucleotide excision repair (to repair thymidine dimers, especially);

autosomal recessive

99
Q

By what age have most individuals with xeroderma pigmentosum developed some sort of skin cancer (often squamous cell carcinoma)?

A

8

100
Q

True/False.

Individuals with xeroderma pigmentosum typically live a normal lifespan.

A

False.

101
Q

What is the most common cause of death among individuals with xeroderma pigmentosum?

A

Squamous cell carcinoma

102
Q

In nucleotide excision repair, what enzyme typically removes the damaged section?

A

An endonuclease

103
Q

In nucleotide excision repair, what enzyme typically refills the removed portion?

A

DNA polymerase

104
Q

In nucleotide excision repair, what enzyme typically seals up the repaired DNA portion?

A

DNA ligase

105
Q

Name three enzymes necessary to nucleotide excision repair.

A

Endonuclease, DNA polymerase, DNA ligase

106
Q

True/False.

Squamous cell carcinoma is associated with mutations in the BRAF and RAS genes.

A

False (SCC is associated with P53 issues);

melanoma is associated with BRAF and RAS

107
Q

Melanoma is associated with mutations in what two genes in particular?

A

BRAF and RAS

108
Q

What two factors does HPV use to increase growth and potential neoplasia in cells?

What do these factors do?

A

E6, E7;

block tumor suppressors

109
Q

What is the name for the disease where it appears that the patient’s skin is turning into tree bark or elephant skin?

What is the underlying issue?

A

Epidermodysplasia verruciformis;

excessive, keratinized, HPV wart-like growths

110
Q

How does squamous cell carcinoma usually present?

A

An ulcerous, crusty, scaly lesion on the head, neck, or dorsum of the hand

111
Q

What are some risk factors for squamous cell carcinoma?

A

Caucasian, immunosuppressed, high sun exposure

112
Q

Squamous cell carcinoma has an association with what infectious agent?

A

HPV

113
Q

Describe the histology of squamous cell carcinoma.

A

Neoplastic cells with keratin pearls

114
Q

How does basal cell carcinoma typically present?

A

Smooth, pink, pearly mass on the head, neck, or dorsum of the hand

(especially the nose, upper lip, and cheek)

115
Q

Mutations in what two genes are associated with basal cell carcinomas?

What drug helps block the pathway related to these mutations?

A

PTCH1, PTCH2;

vismodegib

116
Q

How does basal cell carcinoma present on histology?

A

Circular blue-purple masses

117
Q

Melanoma is positive for what marker?

A

S100

118
Q

What type of genetic pathway inhibitor is used in melanoma treatment?

A

BRAF inhibitors

119
Q

What is a squamous cell carcinoma precursor lesion (not necessary for its development though)?

A

Actinic keratosis

120
Q

Cervical epithelial dysplasia is to cervical cancer

as

actinic keratosis is to _____________.

A

Squamous cell carcinoma

121
Q

True/False.

All squamous cell carcinomas develop from actinic keratosis.

A

False.

122
Q

What is Nikolsky’s sign?

What does it indicate?

A

Epidermal sloughing due to manual stroking;

a very severe blistering disease

123
Q

A patient with severe blisters and associated skin lesions presents to the clinic. You note that the superficial layer of her diseased skin sloughs off when your hand passes gently over it.

What is this sign called and what does it indicate?

A

Nikolsky’s sign;

a severe blistering disease

124
Q

What are the A and B of the ABCDEs of melanoma?

A

Asymmetry;

border irregularity

125
Q

What are the C and D of the ABCDEs of melanoma?

A

Color;

diameter

126
Q

What is the E of the ABCDEs of melanoma?

A

Evolution (change over time)

127
Q

What is the most common type of melanoma?

Is it generally a better or worse prognosis than the others?

A

Superficial spreading melanoma;

better (relatively treatable)

128
Q

Of the two more common subtypes of melanoma, which is the more aggressive and deadly?

A

Nodular melanoma

129
Q

What is a slow-growing, in-situ melanoma most often found in the elderly?

A

Lentigo maligna

130
Q

What very deadly form of melanoma is most often found in patients with darker skin tones?

A

Acral lentiginous

131
Q

Epidermolysis bullosa simplex is caused by what underlying defect?

How does it typically present?

A

Defective keratins 5 and 14;

pediatric friction-induced blisters on hands and feet

132
Q

Epidermolysis bullosa simplex affects what cellular junction?

It mostly affects what cell layer?

A

Hemidesmosomes;

the (epidermal) stratum basale

133
Q

What autoimmune disorder affects hemidesmosomes of the stratum basale?

What congenital disorder affects hemidesmosomes of the stratum basale?

A

Bullous pemphigoid;

epidermolysis bullosa simplex

134
Q

What autoimmune disorder affects desmosomes of the stratum spinosum?

What congenital disorder affects type VII collagen of the basement membrane?

A

Pemphigus vulgaris;

dystrophic epidermolysis bullosa

135
Q

A three-year-old girl is brought to the clinic for examination of frequent blisters on her hands and feet.

What is the likely diagnosis and what causes this disorder?

A

Epidermolysis bullosa simplex;

congenital defect in keratins 5 and 14 (of the hemidesmosomes of the stratum basale)

136
Q

Epidermolysis bullosa simplex affects what layer of the epidermis?

A

The stratum basale

137
Q

A 55-year-old patient presents with widespread, pruritic ulcers and skin erosions that affect the oral cavity, scalp, chest, and other portions of the body.

Immunofluorescene of a skin biopsy shows a net-like pattern in the stratum spinosum.

What is the diagnosis?

A

Pemphigus vulgaris

138
Q

Pemphigus vulgaris affects what layer of the epidermis?

A

The stratum spinosum

139
Q

Which typically presents with blisters, pemphigus vulgaris or bullous pemphigoid?

What antibody type causes both disorders?

A

Bullous pemphigoid;

IgG

140
Q

Which epidermal layer is typically affected by bullous pemphigoid?

A

The stratum basale

141
Q

How is pemphigus vulgaris treated?

This is to prevent suppression of autoantibodies against what structure(s)?

A

Steroids (e.g. prednisone);

desmoglein I and III

142
Q

How does pemphigus vulgaris present on immunofluoresence?

How does bullous pemphigoid present on immunofluoresence?

A

Net-like pattern in the stratum spinosum;

linear pattern at dermoepidermal junction

143
Q

Bullous pemphigoid is caused by autoantibodies against what two proteins?

This affects what type of cellular junction?

A

BPAG1, BPAG2;

hemidesmosomes

144
Q

What is a congenital disorder resulting from defects in keratin 5 and 14?

What is an autoimmune disorder resulting from autoantibodies against desmoglein 1 and 3?

What is a congenital disorder resulting from defects in collagen VII?

What is an autoimmune disorder resulting from autoantibodies against BPAG1 and BPAG2?

A

Epidermolysis bullosa simplex;

pemphigus vulgaris;

dystrophic epidermolysis bullosa;

bullous pemphigoid

145
Q

What is a congenital disorder of the epidermis resulting in hemidesmosomal dysfunction?

What is an autoimmune disorder of the epidermis resulting in desmosomal dysfunction?

What is a congenital disorder of the epidermis of the epidermis resulting in basement membrane dysfunction?

What is an autoimmune disorder of the epidermis resulting in hemidesmosomal dysfunction?

A

Epidermolysis bullosa simplex;

pemphigus vulgaris;

dystrophic epidermolysis bullosa;

bullous pemphigoid

146
Q

What age range is typically affected by pemphigus vulgaris or bullous pemphigoid?

A

50s to 60s

147
Q

What protein is affected in dystrophic epidermolysis bullosa?

This leads to what problem?

A

Collagen VII;

separation of the basal lamina and reticular lamina

148
Q

True/False.

Dystrophic epidermolysis bullosa typically results in widespread ulceration, dehydration, infection, and even finger resoprtion. This constellation of issues typically results in early death.

A

True.

149
Q

Epidermolysis bullosa simplex typically affects what layer of the skin?

Pemphigus vulgaris typically affects what layer of the skin?

Dystrophic epidermolysis bullosa typically affects what layer of the skin?

Bullous pemphigoid typically affects what layer of the skin?

A

The stratum basale (hemidesmosomes);

the stratum spinosum (desmosomes);

the basement membrane (type VII collagen);

the stratum basale (hemidesmosomes)

150
Q

An 8-year-old girl is brought to see you in the clinic. Her parents show you a small lesion (1 cm diameter) with an ulcerous, scaly center. Upon skin examination, another such lesion is noticed on the back of the hand.

You notice that the patient’s face is nearly covered in freckles.

What is the diagnosis of the lesions?

What is the larger diagnosis to be made?

A

Squamous cell carcinoma;

xeroderma pigmentosum (autosomal recessive)

151
Q

Name the drug that is a thymine analog that blocks reverse transcriptase.

How does it accomplish this?

A

Zidovudine (AZT);

the 3’-hydroxyl is replaced with a nitrogenous compound

152
Q

Name the drug that is a purine analog that blocks reverse transcriptase.

How does it accomplish this?

A

2’,3’-dideoxyinosine;

the 3’-hydroxyl is replaced with hydrogen groups

153
Q

Zidovudine (AZT) is an analog of what compound?

What enzyme does it block?

What types of disease is it used to treat?

A

Thymine;

reverse transcriptase;

retroviruses

154
Q

2’,3’-dideoxyinosine is an analog of what compound?

What enzyme does it block?

What types of disease is it used to treat?

A

Purines;

reverse transcriptase;

retroviruses

155
Q

What specific portion of a nucleotide can be modified in order to halt DNA synthesis?

A

The 3’-hydroxyl

156
Q

What drug is used to treat HSV?

What drug is used to treat CMV?

A

Acyclovir;

gancyclovir

157
Q

What are acyclovir and gancyclovir?

What are they used to treat, respectively?

A

Guanosine analogs;

HSV, CMV

158
Q

Will acyclovir and gancyclovir be phosphorylated in all human cells?

Why or why not?

A

No;

just infected cells (where viral kinase is present)

159
Q

What drug is used to treat HSV?

What forms of HSV?

A

Acyclovir;

cold sores, varicella zoster, herpes zoster

160
Q

What drug is used to treat CMV retinitis?

A

Gancyclovir

161
Q

What disease is characterized by a mutation in the MLH1 or MLH2 genes that begin mismatch excision repair by identifying mispairing?

A

Hereditary nonpolypoisis colorectal cancer

162
Q

Hereditary nonpolypoisis colorectal cancer is commonly associated with a mutation in one of which two genes?

These genes are related to what normal cellular function?

A

MLH1, MLH2;

mismatch excision repair

163
Q

What type of cancer is commonly linked to a defect in mismatch excision repair?

A

Hereditary nonpolypoisis colorectal cancer

164
Q

Xeroderma pigmentosum is related to a defect in what normal cellular function?

This normal cellular function is responsible for what process?

A

Nucleotide excision repair;

fixing thymidine dimers

165
Q

How can one remember that xeroderma pigmentosum is related to defects in nucleotide excision repair?

A

The proteins are named after xeroderma pigmentosum

(e.g. XP-C, XP-F, XP-G)

166
Q

Besides squamous cell carcinoma and other skin malignancies, what may be some symptoms of xeroderma pigmentosum?

A

Progressive neurological complications, including loss of sight or hearing.

167
Q

The lifespan of an individual with xeroderma pigmentosum is shortened by how long?

A

~30 years

168
Q

Besides xeroderma pigmentosum, what is another disease related to defects in nucleotide excision repair?

What are the two main manifestations of this disorder?

A

Cockayne syndrome;

neurological defects and premature aging

169
Q

Cockayne syndrome is associated with defects in what cellular system?

Cockayne syndrome is associated with mutations of what genes?

A

Nucleotide excision repair;

ERCC6; ERCC8

170
Q

Name the enzyme responsible for each of the following in nucleotide excision repair:

  • scanning and recognition of errors -
  • helicase activity -
  • endonucleases (2) -
A

XP-C

TFIIH

XP-F, XP-G

171
Q

What form of Cockayne syndrome is associated with a mutation in ERCC8?

What form of Cockayne syndrome is associated with a mutation in ERCC6?

A

CS A

CS B

172
Q

What does the WT1 (mutations associated with Wilm’s tumor) gene do?

A

Repress oncogenic function

(at the proximal promoter)

173
Q

Where on the gene does the WT1 gene repress oncogenic activity?

A

The proximal promoter

174
Q

Besides phalloidin, what other toxin is found in death cap mushrooms?

How does it exert its toxic effects?

A

Alpha-amanitin;

prevents RNA polymerase II binding

175
Q

What effect does alpha-amanitin have on normal cellular processes?

How does this manifest?

A

Blocks RNA polymerase II;

liver damage –> flu-like symptoms –> coma –> death

176
Q

What two toxins do death cap mushrooms contain that stabilize F-actin and block RNA polymerase II, respectively?

A

Phalloidin;

alpha-amanitin

177
Q

In HIV, viral cyclin T binds host CDK9. What is the effect?

A

Hyperphosphorylation of RNA polymerase II

178
Q

What effect does HIV have on RNA polymerase II via hyperphosphorylation?

A

Overactivation

179
Q

Where does the beta-thalassemia mutation occur?

A

The beta-globulin locus

180
Q

Lupus tends to affect what part of the spliceosome?

This has what immediate effect?

A

snRNPs;

splicing does not occur, and hnRNA is not turned into mRNA

(hnRNA thus builds up in the nucleus)

181
Q

What is leukoencephalopathy with CNS hypomyelination and vanishing white matter (VWM)?

A

Loss of cerebral white matter / oligodendrocytes following an acute fever

182
Q

What defect causes leukoencephalopathy with CNS hypomyelination and vanishing white matter (VWM)?

Why do the neurological symptoms often appear following a fever?

A

A defect in eukaryotic intiation factor 2 (eIF2);

eIF2 plays a role in responding to cellular stress

(if it is defective, the response is dimished)

183
Q

Besides assisting in formation of the preinitiation complex (PIC) for translation, what else does eukaryotic initiation factor 2 do?

How?

A

Responds to cellular stress (e.g. heat);

stalls translation during times of heat so that denatured proteins don’t build up and accumulate

184
Q

What is a eukaryotic initation factor (eIF) that is involved in translation and also cellular responses to high temperatures?

(Note: this protein stalls translation during times of high heat in order to prevent accumulation/aggregation of denatured proteins)

A

eIF2

185
Q

What is it called when amyloid (not always amyloid though!) protein misfolds and aggregates/accumulates within cells?

What shape are the proteins in when aggregated?

A

Amyloidosis (not always amyloid!);

beta-sheets

186
Q

Misfolding of what protein is associated with type II diabetes?

What is the effect?

A

Amylin;

beta-cell apoptosis

187
Q

What is an infectious amyloidosis involving misfolded proteins?

What protein is involved?

A

Prion disease

PrPc

188
Q

Alzheimer’s disease is associated with beta-amyloid plaques that are accumulations of what protein?

A

Amyloid precursor protein

189
Q

Misfolding of what protein is associated with Huntington’s disease?

What are the repeats in the involved gene?

A

HTT protein;

CAG

190
Q

Misfolding of what protein is associated with Parkinson’s disease?

What are the associated aggregates called?

A

Alpha-synuclein;

Lewy bodies

191
Q

Misfolding of what protein is associated with ALS?

A

Superoxide dismutase (SOD1)

192
Q

Misfolding of what protein is associated with spinal cerebellar ataxia?

What are the repeats in the involved gene?

A

Ataxin;

CAG

193
Q

Misfolding of amylin and associated amyloidosis is associated with what disease?

A

Type II diabetes

194
Q

Misfolding of amyloid precursor protein and associated amyloidosis is associated with what disease?

A

Alzheimer’s disease

195
Q

The PrPc protein and associated amyloidosis is associated with what disease?

A

Prion diseases (e.g. CJD)

196
Q

Misfolding of the HTT protein and associated amyloidosis is associated with what disease?

A

Huntington’s disease

197
Q

Misfolding of alpha-synuclein and associated amyloidosis is associated with what disease?

A

Parkinson’s disease

(I think, also Lewy body dementia)

198
Q

Misfolding of the superoxidase dismutase (SOD1) protein and associated amyloidosis is associated with what disease?

A

Amyotrophic lateral sclerosis

199
Q

Misfolding of ataxin and associated amyloidosis is associated with what disease?

A

Spinal cerebellar ataxia

200
Q

What effect does phalloidin (found in death cap mushrooms) have on cells?

What effect does alpha-amanitin (found in death cap mushrooms) have on cells?

A

F-actin stabilization;

RNA polymerase II inhibition

T1 - Phase 1 - Integrated (I) (28 decks)

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