Intro to Skin and Gastroinfections

Question 1

Defenses of the skin

Answer 1

keratinized surfice
sloughing
low pH
high salt
lysozyme
normal biota

Question 2

2 causative organisms of warts

Answer 2

HPV

molluscum contaglosum viruses

Question 3

Detects cercival cancer

Answer 3

Pap smear

do not want to see giant cells

Question 4

Exanthem

Answer 4

widespread rash usually occurring in children
caused by toxins, drugs, infections, and autoimmune diseases
6 classic childhood exanthems

Question 5

First Disease

Answer 5

Measles

Question 6

Second Disease

Answer 6

Streptococcus pyogenes

Question 7

Third Disease

Answer 7

Rubella

Question 8

Fourth Disease

Answer 8

Staphylococcus aureus

Question 9

Fifth Disease

Answer 9

Parvovirus B19

Question 10

Sixth Disease

Answer 10

Human Herpes virus 6B/7 (Roseoloviruses)

Question 11

Fifth disease sympmtoms

Answer 11

results in characteristic slapped cheek appearance
caused by parvovirus B19
Red with papules on surface

Question 12

Family of Parvovirus B19

Answer 12

Parvoviridae

Question 13

What cells does parvovirus infect?

Answer 13

ertyhroid percursor cells in bone marrow

Question 14

Early phase of parvovirus

Answer 14

flu like, viral shedding occurs

Question 15

Later phase of parvovirus

Answer 15

rash, athritis caused by circulating antibody

Question 16

Aplastic chrisis

Answer 16

occurs in patients with chronic hemolytic anemia when their red blood cells drop

Question 17

Common ability of all hepatitis viruses

Answer 17

cause liver inflammation and disease

Question 18

HAV family

Answer 18

Picornaviridiae

Question 19

HAV genome

Answer 19

+ ssRNA

no envelope

Question 20

HBV family

Answer 20

hepadnaviridae

Question 21

HBV genome

Answer 21

partially dsDNA
has reverse transcritase
Enveloped

Question 22

HCV family

Answer 22

Falviviridae

Question 23

HCV genome

Answer 23

+ ssRNA

enveloped

Question 24

HAV clinical presenation

Answer 24

Fecal to Oral transmission
short incubation
acute infection

Question 25

HBV and HCV clinical presentation

Answer 25

Blood, sexual contact transmission
Long incubation
acute infection
chronic infection

Question 26

Treatment for HBV

Answer 26

alpha interferon, lamivudine, hepatitis B, immune globulin

Question 27

Treatment for HCV

Answer 27

alpha interferon
ribavirin
boceprevir
telaprevir

Question 28

What can we use passive immunoziation for?

Answer 28

HAV and HBV

Question 29

What’s special about the Hep A virus

Answer 29

capsid is very stable and can remain in the environment for a long time
VPg protein covalently attached to 5’ end

Question 30

Route of Hep A infection

Answer 30

consume contaiminated water, goes through GI tract, hits the bloodstream, replicates in hepatocytes in liver, gets secreted into the environment (10 days before jaundice)

Question 31

Is HAV cytotoxic?

Answer 31

No, the response we see is from CD8+ T cells that are trying to kill the host cell
Can clear infection with cell mediated immunity

Question 32

How come HBV and HCV don’t recover on their own?

Answer 32

The virus spreads before CD8T cells can wipe out initial cells, so CD8 can never quite catch up

Question 33

Symptoms of HAV

Answer 33

fever, fatigue, nausea, loss of appteite, abdominal pain, dark urine, jaundice

Question 34

When do IgM and IgG kick in?

Answer 34

When symptoms start, IgM peaks
At 8 weeks we have specific IgG
Virus is in feces for first 3-4 weeks

Question 35

Treatment for Hep A

Answer 35

prophylaxis with immune globulin serum for those who have been in contact with HAV individual
Killed HaV vaccine for travelers

Question 36

4 functions of Polyermase enzyme

Answer 36

Primer
Reverse Transcription
RNAase (can degrade RNA)
DNA dependent DNA pol (Make + strand of DNA)

Question 37

Hep B spread in body and symptom appearance

Answer 37

source is blood, semen, milk, vaginal and menstrual secretions, amniotic fluid
can take 45 days for symptoms to appear

Question 38

Stages of Hep B

Answer 38

90% resolution
9% become chronic where some resolve, some are asymptomatic carries, some have chronic persistent hep which causes disase, and some are chronic active hep which causes cirrhosis and hepatic cell carcinoma

Question 39

Hep B treatments

Answer 39

Prophylaxis with immune globulin serum
Chronic is treated with lamivudine (reverse transcriptase inhibitor)
Adefovir, dipivoxil, and famciclovir block viral genome rep
take for one year

Question 40

How many hep C infections become chronic?

Answer 40

70-80%

Question 41

How does HCV progress

Answer 41

very slowly, 10 to 20 yeears post infection before symptoms appear

Question 42

Outcomes of HCV

Answer 42

70% have persisent infection that has half asymptomatic while some have liver failure, cirrhosis, or carcinoma

Question 43

How does HCV infect liver cells?

Answer 43

expresses the CD81 surface receptor. Uses the lipoprotein receptor facilitate uptake into hepatocytes. HCV proteins hihibit celullar apotosis and interferon alpha action

Question 44

Treatment for HCV

Answer 44

protease inhibitors

interferon alpha

Question 45

major causes of viral gastroenteritis

Answer 45

rotavirus

norwalk virus

Question 46

Rotavirus family

Answer 46

reoviridae

Question 47

How does rotavirus attack?

Answer 47

Virus enters body through mouth
VP4 proteins attach virus to gut
Enters cytoplasm and infects
fluid and othe rmatter leave as watery diarhea

Question 48

Rotavirus vaccine

Answer 48

rotarix