Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Rapid Rev USMLE 1 > Rev25 > Flashcards

Rev25 Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

What deficiency leads to hyperuricemia and Lesch-Nyhan syndrome?

A

HGPRT deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the likely cause of iatrogenic chylothorax following thoracic surgery?

A

Thoracic duct injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What embryologic structures are affected in DiGeorge syndrome?

A

Third and fourth pharyngeal pouches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the synovial fluid findings in rheumatoid arthritis?

A

Decreased Complement (C3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the typical MRI finding in Wernicke encephalopathy?

A

Atrophy of mammillary bodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which monoclonal antibodies can increase the risk of TB reactivation in Crohn’s disease?

A

Anti-TNF-alpha antibodies (infliximab

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the key features of antiphospholipid syndrome?

A

Increased PTT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the result of extravasated sperm post-vasectomy?

A

Granulomatous response forming a sperm granuloma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the recurrence risk for congenital heart defects in couples with one affected child?

A

3-5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What can increase pulmonary lymphatic flow in experimental models?

A

Increased pulmonary capillary hydrostatic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the key factors in grading breast carcinoma?

A

Degree of differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What causes normal PT/INR during initial warfarin therapy?

A

Delayed effect of warfarin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the mechanism of primaquine in malaria treatment?

A

Elimination of hypnozoites to prevent relapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What organism commonly causes diarrhea in HIV patients?

A

Cryptosporidium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What compound is reduced in osteoarthritic joints?

A

Proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What neurodegenerative disease is associated with REM sleep behavior disorder?

A

Parkinson’s disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does the thyroid hormone receptor affect transcription in the absence of T3?

A

Histone deacetylase activity inhibits transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does the thyroid hormone receptor affect transcription in the presence of T3?

A

Histone acetyltransferase activity activates transcription

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What buffers calcium ion concentration in the sarcoplasmic reticulum?

A

Calsequestrin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What mutation prevents plasmid replication in bacteria?

A

Origin of replication (ori) mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What enzyme deficiency is associated with mucolipidosis II?

A

Defective mannose phosphorylation in the Golgi apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the cause of increased CK-MB and troponin I post-stenting?

A

Reperfusion injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What causes pulsus paradoxus in cardiac tamponade?

A

Exaggerated decrease in systolic blood pressure during inspiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What increased serum component is indicative of cryoglobulinemia in hepatitis C?

A

Cryoglobulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What causes REM sleep behavior disorder?

A

Absent muscle atonia during REM sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What embryologic sites are affected in a right-sided aortic arch and hypocalcemia?

A

Third and fourth pharyngeal pouches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What histologic pattern is seen in Peutz-Jeghers syndrome polyps?

A

Hamartomatous polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What enzyme activity decreases in osteoarthritic joints?

A

Proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What enzyme deficiency leads to hyperuricemia?

A

HGPRT deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the likely cause of iatrogenic chylothorax?

A

Thoracic duct injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Question

A

Answer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the function of Interleukin-1 (IL-1)?

A

Causes fever, acute inflammation. Activates endothelium to express adhesion molecules. Induces chemokine secretion to recruit WBCs. Also called osteoclast-activating factor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the mnemonic for Interleukin-1 (IL-1)?

A

Hot T-bone stEAK (IL-1: fever [hot])

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the function of Interleukin-2 (IL-2)?

A

Stimulates growth of helper, cytotoxic, and regulatory T cells, and NK cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the mnemonic for Interleukin-2 (IL-2)?

A

T-bone stEAK (IL-2: stimulates T cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is the function of Interleukin-3 (IL-3)?

A

Supports growth and differentiation of bone marrow stem cells. Functions like GM-CSF.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the mnemonic for Interleukin-3 (IL-3)?

A

T-bone stEAK (IL-3: stimulates bone marrow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the function of Interleukin-4 (IL-4)?

A

Induces differentiation of T cells into Th2 cells. Promotes growth of B cells. Enhances class switching to IgE and IgG.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the mnemonic for Interleukin-4 (IL-4)?

A

Ain’t too proud 2 BEG 4 help (IL-4)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the function of Interleukin-5 (IL-5)?

A

Promotes growth and differentiation of B cells. Enhances class switching to IgA. Stimulates growth and differentiation of eosinophils.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is the mnemonic for Interleukin-5 (IL-5)?

A

I have 5 BAEs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the function of Interleukin-6 (IL-6)?

A

Causes fever and stimulates production of acute-phase proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the mnemonic for Interleukin-6 (IL-6)?

A

T-bone stEAK (IL-6: stimulates aKute-phase protein production)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the function of Tumor Necrosis Factor-α (TNF-α)?

A

Activates endothelium. Causes WBC recruitment, vascular leak. Causes cachexia in malignancy. Maintains granulomas in TB. Can mediate fever and sepsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the function of Interleukin-8 (IL-8)?

A

Major chemotactic factor for neutrophils.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the mnemonic for Interleukin-8 (IL-8)?

A

Clean up on aisle 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the function of Interleukin-12 (IL-12)?

A

Induces differentiation of T cells into Th1 cells. Activates NK cells. Facilitates granuloma formation in TB.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the function of Interferon-γ (IFN-γ)?

A

Secreted by NK cells and T cells in response to antigen or IL-12 from macrophages. Stimulates macrophages to kill phagocytosed pathogens. Inhibits differentiation of Th2 cells. Induces IgG isotype switching in B cells. Increases MHC expression and antigen presentation by all cells. Activates macrophages to induce granuloma formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is the function of Interleukin-10 (IL-10)?

A

Attenuates inflammatory response. Decreases expression of MHC class II and Th1 cytokines. Inhibits activated macrophages and dendritic cells. Also secreted by regulatory T cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the function of Interleukin-13 (IL-13)?

A

Promotes IgE production by B cells. Induces alternative macrophage activation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is the mnemonic for Interleukin-13 (IL-13)?

A

Interleukin thirtEEn promotes IgE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is the defect in X-linked (Bruton) Agammaglobulinemia?

A

Defect in BTK, a tyrosine kinase gene → no B-cell maturation; X-linked recessive (↑ in Boys)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the presentation of X-linked (Bruton) Agammaglobulinemia?

A

Recurrent bacterial and enteroviral infections after 6 months (↓ maternal IgG)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What are the findings in X-linked (Bruton) Agammaglobulinemia?

A

Absent B cells in peripheral blood, ↓ Ig of all classes, absent/scanty lymph nodes and tonsils (1° follicles and germinal centers absent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the defect in Selective IgA Deficiency?

A

Unknown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the presentation of Selective IgA Deficiency?

A

Majority Asymptomatic; can see airway and GI infections, autoimmune disease, atopy, anaphylaxis to IgA in blood products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the findings in Selective IgA Deficiency?”

A

↓ IgA with normal IgG, IgM levels; ↑ susceptibility to giardiasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the defect in Common Variable Immunodeficiency?

A

Defect in B-cell differentiation. Cause unknown in most cases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the presentation of Common Variable Immunodeficiency?

A

May present in childhood but usually diagnosed after puberty. ↑ risk of autoimmune disease, bronchiectasis, lymphoma, sinopulmonary infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What are the findings in Common Variable Immunodeficiency?

A

↓ plasma cells, ↓ immunoglobulins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What is the defect in Thymic Aplasia (DiGeorge Syndrome)?

A

22q11 microdeletion; failure to develop 3rd and 4th pharyngeal pouches → absent thymus and parathyroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the presentation of Thymic Aplasia (DiGeorge Syndrome)?

A

CATCH-22: Cardiac defects, Abnormal facies, Thymic hypoplasia, Cleft palate, Hypocalcemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What are the findings in Thymic Aplasia (DiGeorge Syndrome)?

A

↓ T cells, ↓ PTH, ↓ Ca2+, thymic shadow absent on CXR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What is the defect in IL-12 Receptor Deficiency?

A

↓ Th1 response; autosomal recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is the presentation of IL-12 Receptor Deficiency?

A

Disseminated mycobacterial and fungal infections; may present after administration of BCG vaccine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the findings in IL-12 Receptor Deficiency?”

A

↓ IFN-γ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the defect in Hyper-IgE Syndrome (Job Syndrome)?

A

Deficiency of Th17 cells due to STAT3 mutation → impaired recruitment of neutrophils to sites of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the presentation of Hyper-IgE Syndrome (Job Syndrome)?

A

Cold staphylococcal abscesses, retained baby teeth, coarse facies, eczema, ↑ IgE, bone fractures from minor trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What are the findings in Hyper-IgE Syndrome (Job Syndrome)?”

A

↑ IgE, ↑ eosinophils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is the defect in Chronic Mucocutaneous Candidiasis?

A

T-cell dysfunction; impaired cell-mediated immunity against Candida sp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the presentation of Chronic Mucocutaneous Candidiasis?

A

Persistent noninvasive Candida albicans infections of skin and mucous membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What are the findings in Chronic Mucocutaneous Candidiasis?”

A

Absent in vitro T-cell proliferation in response to Candida antigens, absent cutaneous reaction to Candida antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What is the defect in Severe Combined Immunodeficiency (SCID)?

A

Several types including defective IL-2R gamma chain (most common, X-linked recessive); adenosine deaminase deficiency (autosomal recessive); RAG mutation → VDJ recombination defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is the presentation of Severe Combined Immunodeficiency (SCID)?

A

Failure to thrive, chronic diarrhea, thrush, recurrent infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What are the findings in Severe Combined Immunodeficiency (SCID)?”

A

↓ T-cell receptor excision circles (TRECs), absence of thymic shadow, germinal centers, and T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What is the defect in Ataxia-Telangiectasia?

A

Defects in ATM gene → failure to detect DNA damage → failure to halt cell cycle progression → mutations accumulate; autosomal recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the presentation of Ataxia-Telangiectasia?

A

Triad: cerebellar defects (Ataxia), spider Angiomas (telangiectasia), IgA deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What are the findings in Ataxia-Telangiectasia?”

A

↑ AFP, ↓ IgA, IgG, and IgE, lymphopenia, cerebellar atrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What is the defect in Hyper-IgM Syndrome?

A

Most commonly due to defective CD40L on Th cells → class switching defect; X-linked recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What is the presentation of Hyper-IgM Syndrome?

A

Severe pyogenic infections early in life; opportunistic infection with Pneumocystis, Cryptosporidium, CMV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What are the findings in Hyper-IgM Syndrome?”

A

Normal or ↑ IgM, ↓ IgG, IgA, IgE, failure to make germinal centers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What is the defect in Wiskott-Aldrich Syndrome?

A

Mutation in WAS gene; leukocytes and platelets unable to reorganize actin cytoskeleton → defective antigen presentation; X-linked recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is the presentation of Wiskott-Aldrich Syndrome?

A

WATER: Wiskott-Aldrich: Thrombocytopenia, Eczema, Recurrent infections; ↑ risk of autoimmune disease and malignancy

84
Q

What are the findings in Wiskott-Aldrich Syndrome?”

A

↓ to normal IgG, IgM; ↑ IgE, IgA; fewer and smaller platelets

85
Q

What is the defect in Leukocyte Adhesion Deficiency (Type 1)?

A

Autosomal recessive defect in LFA-1 integrin (CD18) protein on phagocytes leads to impaired migration and chemotaxis by C5a, IL-8, and leukotriene B4

86
Q

What is the presentation of Leukocyte Adhesion Deficiency (Type 1)?

A

Late separation (>30 days) of umbilical cord, absent pus, dysfunctional neutrophils → recurrent skin and mucosal bacterial infections

87
Q

What are the findings in Leukocyte Adhesion Deficiency (Type 1)?”

A

↑ neutrophils in blood, absence of neutrophils at infection sites

88
Q

What is the defect in Chédiak-Higashi Syndrome?

A

Defect in lysosomal trafficking regulator gene (LYST); microtubule dysfunction in phagosome-lysosome fusion; autosomal recessive

89
Q

What is the presentation of Chédiak-Higashi Syndrome?

A

PLAIN: Progressive neurodegeneration, Lymphohistiocytosis, Albinism (partial), recurrent pyogenic Infections, peripheral Neuropathy

90
Q

What are the findings in Chédiak-Higashi Syndrome?”

A

Giant granules in granulocytes and platelets, pancytopenia, mild coagulation defects

91
Q

What is the defect in Chronic Granulomatous Disease?

A

Defect of NADPH oxidase → ↓ reactive oxygen species (e.g., superoxide) and ↓ respiratory burst in neutrophils; X-linked form most common

92
Q

What is the presentation of Chronic Granulomatous Disease?

A

↑ susceptibility to catalase-positive organisms, recurrent infections, and granulomas

93
Q

What are the findings in Chronic Granulomatous Disease?”

A

Abnormal dihydrorhodamine (flow cytometry) test (↓ green fluorescence), nitroblue tetrazolium dye reduction test fails to turn blue

94
Q

What is the change in cardiac parameters during inspiration?

A

↑ RV preload, ↓ LV preload

95
Q

What murmurs increase during inspiration?

A

Most right-sided murmurs (↑ RV blood volume)

96
Q

What murmurs decrease during inspiration?

A

Most left-sided murmurs (↓ LV blood volume)

97
Q

What is the change in cardiac parameters during Valsalva strain phase?

A

↓ RV & LV preload

98
Q

What murmurs increase during Valsalva strain phase?

A

MVP & HCM (↓ LV blood volume)

99
Q

What murmurs decrease during Valsalva strain phase?

A

Most valvular murmurs (↓ flow through valve)

100
Q

What is the change in cardiac parameters during abrupt standing?

A

↓ RV & LV preload

101
Q

What murmurs increase during abrupt standing?

A

MVP & HCM (↓ LV blood volume)

102
Q

What murmurs decrease during abrupt standing?

A

Most valvular murmurs (↓ flow through valve)

103
Q

What is the change in cardiac parameters during squatting?

A

↑ RV & LV preload, ↑ LV afterload

104
Q

What murmurs increase during squatting?

A

Most valvular murmurs (↑ flow through valve)

105
Q

What murmurs decrease during squatting?

A

MVP & HCM (↑ LV blood volume)

106
Q

What is the change in cardiac parameters during passive leg raise?

A

↑ RV & LV preload

107
Q

What murmurs increase during passive leg raise?

A

Most valvular murmurs (↑ flow through valve)

108
Q

What murmurs decrease during passive leg raise?

A

MVP & HCM (↑ LV blood volume)

109
Q

What is the change in cardiac parameters during hand grip?

A

↑ LV afterload

110
Q

What murmurs increase during hand grip?

A

AR, MR & VSD (↑ aortic & LV pressure)

111
Q

What murmurs decrease during hand grip?

A

AS (↓ transvalvular pressure gradient)

112
Q

What is the protein defect in Familial Chylomicronemia Syndrome (Type I)?

A

Lipoprotein lipase, ApoC-2

113
Q

What are the elevated lipoproteins in Familial Chylomicronemia Syndrome (Type I)?

A

Chylomicrons

114
Q

What are the major manifestations of Familial Chylomicronemia Syndrome (Type I)?

A

Acute pancreatitis, Lipemia retinalis, Eruptive xanthomas

115
Q

What is the protein defect in Familial Hypercholesterolemia (Type II A)?

A

LDL receptor, ApoB-100

116
Q

What are the elevated lipoproteins in Familial Hypercholesterolemia (Type II A)?

A

LDL

117
Q

What are the major manifestations of Familial Hypercholesterolemia (Type II A)?”

A

Premature atherosclerosis, Tendon xanthomas, Xanthelasmas

118
Q

What is the protein defect in Familial Dysbetalipoproteinemia (Type III)?

A

ApoE

119
Q

What are the elevated lipoproteins in Familial Dysbetalipoproteinemia (Type III)?

A

Chylomicron & VLDL remnants

120
Q

What are the major manifestations of Familial Dysbetalipoproteinemia (Type III)?”

A

Premature atherosclerosis, Tuboeruptive & palmar xanthomas

121
Q

What is the protein defect in Familial Hypertriglyceridemia (Type IV)?

A

Polygenic

122
Q

What are the elevated lipoproteins in Familial Hypertriglyceridemia (Type IV)?

A

VLDL

123
Q

What are the major manifestations of Familial Hypertriglyceridemia (Type IV)?”

A

Associated with coronary disease, pancreatitis & diabetes

124
Q

If the concentration of Drug X is 100 times greater than Km, what governs the reaction?

A

A zero-order rate of metabolism governs the reaction

125
Q

In a tumor cell line where MHC I expression is inhibited, what is the response of CD8+ T lymphocytes, CD4+ T lymphocytes, and natural killer cells?

A

CD8+ T lymphocytes: –; CD4+ T lymphocytes: –; Natural killer cells: +

126
Q

What is the most likely cause of a 56-year-old man with alcoholism having severe stomach pain, foul-smelling stool, significant weight loss, and pancreatic calcifications?

A

Decrease in fecal elastase (indicative of exocrine pancreatic insufficiency)

127
Q

Lesch-Nyhan Syndrome: Defect in the salvage of which bases?

A

Purine bases (HGPRT enzyme deficiency)

128
Q

Symptoms of Lesch-Nyhan Syndrome?

A

Intellectual disability

129
Q

Peripheral Blood Smear Analysis suggests megaloblastic anemia when?

A

Hypersegmented neutrophils and oval macrocytes are present

130
Q

Most likely cause of Philadelphia chromosome in leukemia?

A

BCR-ABL gene involvement

131
Q

Key exposure and radiographic findings for Histoplasma Capsulatum?

A

Bat habitats

132
Q

Histoplasma Capsulatum virulence depends on?

A

Ability to survive and multiply within macrophages

133
Q

Mechanism of Donepezil in Alzheimer’s disease?

A

Acetylcholinesterase inhibition increases acetylcholine levels

134
Q

Treatment for Methanol Poisoning?

A

Fomepizole inhibits alcohol dehydrogenase

135
Q

COPD diagnosis is based on which PFT findings?

A

Decreased FEV1/FVC ratio

136
Q

Symptoms and lab findings of Medium-Chain Acyl-CoA Dehydrogenase Deficiency?

A

Hypoglycemia with normal fasting ketogenesis when fed medium-chain triglycerides

137
Q

Carnitine Palmitoyltransferase II (CPT II) Deficiency symptoms and labs?

A

Muscle weakness

138
Q

Attributable Risk (AR) formula?

A

AR = Incidence in Exposed - Incidence in Unexposed

139
Q

Relative Risk (RR) formula?

A

RR = Incidence in Exposed / Incidence in Unexposed

140
Q

Relative Risk Reduction (RRR) formula?

A

RRR = 1 - RR

141
Q

Number Needed to Treat (NNT) formula?

A

NNT = 1 / ARR

142
Q

Number Needed to Harm (NNH) formula?

A

NNH = 1 / AR

143
Q

Cutaneous T-cell Lymphoma (Mycosis Fungoides) symptoms?

A

Chronic skin lesions

144
Q

Renal Tubular Acidosis in children symptoms?

A

Short stature

145
Q

Pathology of increased lysosomal enzyme activity?

A

Defective protein targeting

146
Q

Risk of Huntington’s Disease for a son of a potential carrier mother?

A

0.25

147
Q

Blood flow redistribution during exercise affects which circulation?

A

Increased vascular resistance in splanchnic (GI) circulation

148
Q

Volume of Distribution (Vd) formula?

A

Vd = Dose / C0

149
Q

Clearance (Cl) formula?

A

Cl = 0.693 * Vd / t1/2

150
Q

Loading Dose (LD) formula?

A

LD = Desired Concentration * Vd / F

151
Q

Maintenance Dose (MD) formula?

A

MD = Desired Concentration * Cl * Dosing Interval / F

152
Q

Bioavailability (F) formula?

A

F = AUC_oral / AUC_IV

153
Q

Corrected Calcium formula?

A

Corrected Ca = Measured Ca + 0.8 * (4.0 - Albumin)

154
Q

What is the key interaction in the development of the metanephros?

A

Induction of the ureteric bud by the metanephric mesenchyme. Reciprocal induction

155
Q

How do you calculate heterozygote frequency in Hardy-Weinberg equilibrium?

A

2pq = 2 x 0.1 x 0.9 = 0.18 or 18%

156
Q

What is a key diagnostic sign of Hemolytic Uremic Syndrome (HUS)?

A

Malaise, dark urine, anemia, low platelets, renal impairment, and schistocytes on blood smear.

157
Q

What enzyme deficiency causes Lesch-Nyhan syndrome?

A

HGPRT deficiency.

158
Q

How do you calculate incidence in a population?

A

Incidence = (New cases) / (Population at risk) = 200/2000 = 0.10 or 10%

159
Q

Which structure is crucial for clavicle fracture healing?

A

Periosteum.

160
Q

What genetic condition is characterized by intellectual disability

A

large head

161
Q

What increases susceptibility to infections in myeloperoxidase deficiency?

A

Impaired production of hydroxy-halide free radicals.

162
Q

What type of collagen is affected in osteoarthritis?

A

Type II collagen.

163
Q

What phase of the menstrual cycle is indicated by secretory endometrium?

A

Secretory phase.

164
Q

What enzyme deficiency is associated with lead poisoning?

A

δ-ALA dehydratase.

165
Q

Which secondary mediator is released in type I hypersensitivity reactions?

A

Leukotrienes.

166
Q

What surface marker indicates Langerhans cell activation?

A

CD1a.

167
Q

What causes HIV drug resistance in patients on reverse transcriptase inhibitors?

A

Mutations in reverse transcriptase.

168
Q

What developmental failure causes cleft lip?

A

Failure of fusion of the maxillary and medial nasal processes.

169
Q

What principle explains mitochondrial inheritance patterns?

A

Maternal inheritance.

170
Q

What disease is associated with retinal hemangioblastomas and cerebellar tumors?

A

Von Hippel-Lindau disease.

171
Q

What is the inheritance pattern of spinal muscular atrophy?

A

Autosomal recessive.

172
Q

Where is the sphenoethmoidal recess located?

A

Superior to the superior concha.

173
Q

What is the pathogenesis of allopurinol-induced acute interstitial nephritis?

A

Immune-mediated hypersensitivity reaction.

174
Q

Which mediator causes tissue injury in pneumonia?

A

Neutrophil elastase.

175
Q

How are patients allocated in an intention-to-treat analysis?

A

400 in the surgical group and 400 in the medical management group.

176
Q

What nerve roots are affected in musculocutaneous nerve injury?

A

C5 and C6.

177
Q

What brain region is affected in a hypoglossal nerve lesion causing tongue deviation?

A

Medulla (left side).

178
Q

What pharmacokinetic change increases drug sensitivity in the elderly?

A

Decreased hepatic metabolism and renal clearance.

179
Q

What explains CD8+ T cell activation in malaria infection?

A

Invasion of malaria parasite into cytoplasm leading to MHC class I presentation.

180
Q

What type of nerves use norepinephrine as a neurotransmitter?

A

Postganglionic sympathetic nerves in the prostate.

181
Q

How many ATP molecules are hydrolyzed per H+ ion secreted by H+

A

K+ ATPase?

182
Q

How long does it take to reach steady-state concentration of a drug?

A

Approximately 4-5 half-lives.

183
Q

What hormone is produced by adipose tissue contributing to estrogen levels?

A

Estrogen.

184
Q

What substance is increased in venous blood in carbonic anhydrase deficiency?

A

HCO3−.

185
Q

What gene is mutated in abetalipoproteinemia?

A

MTTP (microsomal triglyceride transfer protein).

186
Q

What is the result of a p53 mutation in Li-Fraumeni syndrome?

A

Decreased gene transcription for DNA repair proteins.

187
Q

What enzyme activates pancreatic trypsinogen?

A

Enterokinase (enteropeptidase).

188
Q

What movement weakness confirms C5-C6 nerve compression?

A

Elbow flexion (biceps).

189
Q

What is the most likely predisposing factor for ureteral lesions in a smoker?

A

Cigarette smoking (transitional cell carcinoma).

190
Q

What enzyme deficiency is common in congenital adrenal hyperplasia (CAH)?

A

21-hydroxylase deficiency.

191
Q

What type of receptor interaction does aripiprazole have?

A

Partial agonist at dopamine receptors.

192
Q

What condition is diagnosed by acute myocardial infarction (MI) symptoms in the elderly?

A

Acute myocardial infarction (MI).

193
Q

Which mRNA is increased by AGEs in mesangial cells?

A

Collagen type IV.

194
Q

What is the role of IκB in the NF-κB pathway?

A

Inhibits NF-κB by sequestering it in the cytoplasm until degraded.

195
Q

What is convenience sampling?

A

Selection based on availability and willingness to participate.

196
Q

What enzyme deficiency is associated with homocystinuria?

A

Cystathionine beta-synthase.

197
Q

How does decreased calcium intake affect bone mineralization?

A

Decreased bone mineral density.

198
Q

What enzyme deficiency causes acute intermittent porphyria?

A

Porphobilinogen deaminase.

199
Q

What organism causes plague with symptoms of lymphadenopathy and respiratory issues?

A

Yersinia pestis.

200
Q

Why do men generally have higher bone mass than women?

A

Men have higher peak bone mass.

201
Q

What is the likely mutation in androgen insensitivity syndrome?

A

Androgen receptor gene.

202
Q

What is the catheter path to the renal artery via femoral access?

A

Femoral artery → external iliac artery → common iliac artery → aorta → renal artery.

203
Q

What physiological change is increased in newborns immediately after birth?

A

Increased blood pressure.

204
Q

What are examples of lysosomal storage diseases?

A

Gaucher disease, Tay-Sachs disease, Niemann-Pick disease.

205
Q

What enzyme deficiencies are associated with glycogen storage diseases?

A

Glucose-6-phosphatase, acid alpha-glucosidase, debranching enzyme, muscle phosphorylase.

206
Q

How do you calculate pretest probability of disease?

A

Pretest Probability = (Number of True Positives + Number of False Negatives) / Total Population

Rapid Rev USMLE 1 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions