Prions/dna Viruses

Front 1

Human prions

Back 1

a. Slow viruses
b. Transmitted→ Kuru, vCJD
c. Inherited→ CJD, GSS, FFI, AS
d. No immune or inflammatory responses

Front 2

Animal slow diseases

Back 2

a. Scrapie, BSE

Front 3

Characteristics of prions

Back 3

a. Lose muscle coordination
b. Show dementia
c. Progressive insomnia
d. Amyloidosis
e. Spongiform encephalopathy

Front 4

Prion infection

Back 4

a. Alpha helix-- good, PrP(C)
b. Beta sheet--bad, PrP (Sc)
c. PrP(C)→ PrP(Sc)
d. Chromosome 20

Front 5

Prion transmission

Back 5

a. Eating BSE cattle meat
b. Introduction of blood products
c. Pituitary growth hormone injection
d. Corneal or dura mater transplants from CJD patients

Front 6

PrPSc aggregates

Back 6

a. Forms amyloid in cerebellum
b. Astrocyte gliosis
c. Depletion of dendritic spines of neurons
d. Apoptosis→ cerebella spongiform encephalopathy

Front 7

Dx of prion disease

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a. Immunofluorescence test on tonsil biopsy
b. Western blot of blood
c. 14-3-3 protein in CSF of CJD patients

Front 8

Erythrovirus B19

Back 8

a. “Parvoviridae”
b. DNA, naked, icosahedral, 1 type, ssDNA

Front 9

Erythrovirus B19 transmission

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i. Respiratory droplets or transplacental
ii. Nasopharynx→ bone marrow (kills erythroid precursors)

Front 10

Erythrovirus B19 pathology

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i. 1st→ viremia and anemia (fever)
ii. 2nd→ immune response→ rash and arthralgia

Front 11

Erythrovirus B19 disease

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i. 65% of adults infected by age 40
ii. Fifth disease→ slapped face rash- 1/5 exanthems
iii. Aplastic crisis in chronic hemolytic anemia patients
iv. Acute polyarthritis→ seen in adults
v. Spontaneous abortion due to infection of seronegative mother

Front 12

Dx of erythrovirus B19

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i. Clinical presentation
ii. ELISA
iii. PCR

Front 13

HPV

Back 13

a. DNA, naked, icosahedral, 75 types, 1-4 are common, dsDNA

Front 14

HPV epidemiology

Back 14

i. HPV types 1-4 are common
ii. 16, 18, 31, 41→ cervical cancer

Front 15

HPV transmission

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i. Breaks in skin
ii. Mucous membrane (STD)
iii. Fomites
iv. Chewing on warts

Front 16

HPV pathology

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i. Warts occur in keratinized skin
ii. Viral stimulated hyperplasia
iii. Koilocytes→ enlarged keratinocytes with clear halos
iv. Condensed nuclei→ characteristic of HPV infection

Front 17

High-risk strains of HPV

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i. E6 and E7 proteins inactivate p53→ enhanced growth and reduced proof-reading of mutaitons

Front 18

HPV disease

Back 18

i. Papillomas (warts)
ii. Common plantar flat warts in children and young adults
iii. Warts grow during pregnancy
iv. Laryngopapillomas (6, 11)→ infants to 50 y/o, single, pedunculated, can block airway in infants
v. Anogenital (6, 11)
vi. Cervical dysplasia, CIN and carcinoma (16, 18)

Front 19

HPV Dx

Back 19

i. Pap smear showing koilocytosis

Front 20

Control of HPV

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i. CD8 T cells eventually kill HPV infected cells

Front 21

BK and JC virus (polyomavirus) epidemiology

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i. Very common
ii. Causes disease only in IC
iii. Most people are latently infected by 15 y/o

Front 22

BK/JC transmission

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i. Respiratory droplets→ epithelium→ lymphocytes→ kidney where it remains latent
ii. JC lysogenizes kidney, B cells, monocytes, astrocytes, and oligodendrocytes
iii. Virus is shed in urine during acute phase and reactivation
iv. No known effects on fetus

Front 23

BK/JC disease

Back 23

i. IC individuals only (AIDS, transplantation, pregnancy)
ii. Hemorrhagic cystitis, nephritis, or urethritis (BK)
iii. Progressive multifocal leukoencephalopathy (white matter, PML)
iv. Lytic infection→ demyelination of oligodendrocytes

Front 24

Dx of BK/JC

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i. PCR of CSF
ii. CT or MRI of brain
iii. DNA analyses of urine
iv. CSF or biopsied tissue are effective for BK and JC

Front 25

Adenovirus

Back 25

a. dsDNA, naked, icosahedral
b. 12 vertex fibers
c. Hemagluttinin
d. Types 1-7 most common
e. Types 4-7= vaccine
f. One of common cold viruses

Front 26

Adenovirus epidemiology

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i. 1st example isolated from adenoid tissue
ii. 52 human types determined by vertex fiber antigen
iii. Terminal knob is a hemagglutinin

Front 27

Adenovirus transmission

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i. Aerosol, close contact, fecal-oral
ii. Resists dessication, detergents, stomach acid, bile, mild chlorination
iii. Infects mucoepithelial cells→ lymphoid tissue

Front 28

Adenovirus Dx

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i. Easily cultured
ii. Displays characteristic inclusion bodies
iii. DNA analysis

Front 29

Adenovirus in gene replacement therapy

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Used as a vector

Front 30

Acute febrile pharyngitis and pharyngoconjunctival fever

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i. Pharyngitis +/- pinkeye
ii. Young children
iii. Resembles strep throat
iv. Mild flu-like
v. Nasal congestion, coryza, cough, malaise, fever, chills, myalgia, HA

Front 31

Acute respiratory tract disease

Back 31

i. Military recruits
ii. Types 4 and 7
iii. Fever, cough, pharyngitis, cervical adenitis

Front 32

Conjunctivitis and keratoconjunctivitis

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i. Follicular conjunctivitis
ii. “Swimming pool conjunctivitis”
iii. Epidemic keratoconjunctivitis (conjunctiva and kornea)
iv. Work-related

Front 33

Gastroenteritis and diarrhea

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i. Major cause→ acute viral gastroenteritis
ii. Hospital diarrhea
iii. Infant diarrhea

Front 34

HSV 1 and 2

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a. dsDNA, enveloped, icosahedral
b. 8 types
c. Latent, recurring infecitons
d. Envelope confers sensitivity to acid, detergents, and drying

Front 35

HSV 1 and 2 replication

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i. Uses its own viral DNA polymerase
ii. Infections are common and benign except in IC
iii. HSV-1/2 are very common and similar→ 90% of population by age 2

Front 36

HSV 1/2 infection

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i. Mucoepithelial cells→ latent infections in peripheral nerve ganglia (trigeminal or sacral ganglia)
ii. Vesicular lesions at infection site (under stress, trauma, UV-B, fever, or immune suppression)

Front 37

Cowdry type A

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1. Acidophilic intranuclear inclusion bodies

Front 38

Syncytia

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1. Giant cells
2. Produced facilitating cell-to-cell spread
3. Avoiding antibody

Front 39

HSV 1 transmission

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1. Direct contact, vesicular fluid or fluids (saliva, vaginal sevetions) via breaks in skin or mucous membrane
2. INFECTIONS ARE ABOVE WAIST

Front 40

HSV 2 transmission

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1. STD
2. At birth
3. INFECTIONS BELOW THE WAIST

Front 41

Tzanch smear

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1. Test of material scraped from base of a vesicle to reveal syncytia and Cowdry type A inclusions
2. Confirmation by immune- or DNA-based methods, or culture
3. Serology only useful for monitoring a primary infection
4. Recurrent infection sdo not show increases in titers

Front 42

Encephalitis

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1. CSF shows lymphocytic pleocytosis
2. Normal glucose
3. Mildy elevated protein
4. Absence of pathogens using Gram stain and culture

Front 43

VZV epidemiology

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i. Chickenpox, 5-9 y/o
ii. Extremely contagious, lifelong immunity
iii. Shingles (zoster) is a late reactivation of chickenpox and is recurrent

Front 44

VZV transmission

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i. Respiratory droplets or skin contact→ respiratory epithelium→ viremia→ liver→ vesiculopustular rash with crops of lesions

Front 45

VZV pathology

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i. VZV causes latent infections in ganglia
ii. Reactive periodically
iii. Infects entire dermatome with shingles

Front 46

Chickenpox

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1. Epithelial cell infection resulting in an exanthema of macules, papules, pustules, vesicles, and shallow ulcers
2. 20-30% of adults may show interstitial pneumonia, which can be fatal
3. Can be fatal in IC
4. Prenatal infection can lead to CNS abnormalities

Front 47

Shingles

Back 47

1. Peripheral nerve cell infection with an eruption in the overlying epidermis
2. Severe pain preceds the rash and may be followed by chronic pain (postherpetic neuralgia)

Front 48

Dx of VZV

Back 48

i. Similar to HSV infections
ii. Serology is useful to determine immunity
iii. A vaccine is available for young children and IC children

Front 49

Epstein-Barr virus

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a. Herpesvirus, HH4, DNA, enveloped

Front 50

Epstein-Barr virus transmission

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i. Infective via saliva→ oral epithelial cells and B cells
ii. Targets B cells as a mitogen and immortalizing agent
iii. Infections can also be latent or lytic
iv. Latently infected individuals shed virus intermittently for life
v. 70% infection by age 30

Front 51

T-cells in Epstein-Barr virus

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i. Resolve infection by destroying the infected B cells→ produces symptoms of mononucleosis

Front 52

Symptoms of mononucelosis (Epstein-Barr virus)

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1. T CELL LYMPHOCYTOSIS
2. Atypical lymphocytes
3. DOWNEY CELLS
4. HETEROPHILE MONONUCLEOSIS

Front 53

Infectious mononucleosis

Back 53

i. B lymphocyte infection
ii. Overactive immune response
iii. Subclinical in young children, more sever in adults
iv. Fatigue, fever, malaise, pharyngitis, LAD

Front 54

Laryngitis

Back 54

i. Hoarseness
ii. Loss of voice
iii. Other viruses are more common causes

Front 55

Hepatitis

Back 55

i. Elevated ALT, AST liver enzymes (90% of cases)
ii. Jaundice (9% of cases)

Front 56

Encephalitis and aseptic meningitis

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i. 1% of cases
ii. Reactivation in pregnancy

Front 57

Burkitt's lymphoma

Back 57

i. AfBL, endemic in African malaria areas
ii. Deficient immune response

Front 58

Hodgkin's lymphoma

Back 58

i. Lymphoid tissue cancer
ii. Deficient immune response

Front 59

Nasopharyngeal carcinoma

Back 59

i. Epithelial cell cancer, endemic in china

Front 60

Hairy oral leukoplakia

Back 60

i. IC individuals