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MCB Exam 4
Dr.Ashgari Exam 4- Viruses
310
Microbiology
Professional
04/16/2011

Additional Microbiology Flashcards

 


 

Cards

Term
T/F: Most viruses are smaller than 0.45 nm, so are detected by electron microscopy.
Definition
True
Term
______________ is the inactive form of a virus. Once inside host it becomes active.
Definition
Virion
Term
What are the general virus characteristics?
Definition

1. Sub-Microscopic

2. Obligate intracellular parasite

3. Host specificity

4. Needs host 4 energy n protein synthesis

 

Term
List the components that make up the virus structure.
Definition

1. Nucleic acid

2. Capsid

3. Envelope

4. Spikes

Term
T/F:  Not all viruses have to have nucleic acids.
Definition
False; all must have it!
Term
What is the function of the virus capsid?
Definition

1. Protects DNA/RNA against damage

2. Involved in recognizing the host surface

3. Facilitates nucleic acid penetration

 

Term
What 2 structures must all virus have?
Definition

Nucleic acids

Capsids

Term
What are virus envelops composed of?
Definition
Host lipids and viral proteins
Term
What are virus spikes used for?
Definition
Recognition and attachment to host
Term
What types of infection can occur with virus?
Definition

1. Lytic = kills host

2. Persistant = small amounts of virus, host lives

3. Transforming = changes genetics, causes cancer

4. Latent = hides in host, no effect on host

Term
What are some of the ways the virus damages the host?
Definition

1. Cell lysis

2. Cell transformation can lead to cancer

3. Produces toxic products

4. Alters host structure such as nuclear or cytoplasm

Term
What is the major virulence factor for viruses?
Definition
The presence of the virus in the cell
Term
What are some ways that viruses can entry into host tissues?
Definition

1. Directly by trauma or insect bite

2. Thru mucous membranes of the resp. tract or alimentary tract.

Term
Where is the most common entry site for viruses?
Definition
Respiratory tract
Term
Define viremia
Definition
When the virus reaches the blood system
Term
What are some of the reasons why viruses are able to grow inside hosts?
Definition

1. Fast action

2. Adapts to host biochemical conditions

3. Able to resist host defense mechanisms

Term
Describe the virus replication cycle.
Definition

1. Attachment

2. Penetration

3. Un coating

4. Provision of energy

5. synthesis of Low MW compounds

6. Nucleic acid and protein synthesis

7. Assembly

8. Release

Term
What are some ways the virus evades the immune responses of the host?
Definition

1. Inhibits the MHC I restricted Ag Presentation so no CD8 response

2. Inhibits MHC II restricted Ag presentation so no Ab, or Ag memory

3. Downregulates CD4 (T-helper cells)

4. Inhibits NK cell lysis

5. Intereferes with apoptosis

6. Evasion of humoral immunity

7. Inhibits cytokine action

 

Term
List the different types of virus-cell interactions.
Definition

1. Permissive or productive infection

2. Abortive or non-productive

3. Persistent

4. latent

5. Cytopathic effects (CPE)

Term
During permissive (productive) infection, the virus is produced and some cells are infected due to _____________.
Definition
Receptors
Term
This type of virus-cell interaction leads to entry of the virus but no further expression occurs after a few genes are turned on.
Definition
Abortive or nonproductive infection
Term
Which virus-cell interaction leads to the production of few viruses from few cells.  Most the cells are infected but they do not die.
Definition
Permissive
Term
During this virus-cell interaction, the virus does not produce itself. Rather it hides within the host.
Definition
Laten infection
Term
The virus-cell interaction that you can visually see under the microscope are CPEs.  What things can you see?
Definition

1. Plaque formation in phage

2. Nuclear/cytoplasm enlargement

3. Nucleus changes

4. Cell fusion, syncytia formation

5. Lysosomes leaking

6. Viral budding, fibroblast

7. Changes in membranes

Term
What are the stages of the One - Step Growth cycle of the virus?
Definition

1. Attach/adsorb to the cell

2. Penetration by fusion or endocytosis

3. Eclipse period

4. Rise = virus particles are detectable

Term
What is the Eclipse period of the One-Step Growth cycle of a virus?
Definition
A phase in the proliferation of viral particles during which the virus cannot be detected in the host.  Penetration, uncoating, and synthesis occurs here.
Term
Define receptor mediated endocytosis.
Definition
Once the virus is inside it attaches to a clathrin coated pit and forms a coated vesicle. It now requires a low pH to cause fusion of virus to endosome and uncoats to release the virus.
Term
T/F: Some viruses use cellular transcriptase and some use viral transcriptase.
Definition
True
Term
Define viral syndrome. And give some examples.
Definition

It is the pathogenic manifestations of a viral infection.

 

1. Flu like and systemic symptoms

2. Infection of the eye, oral, resp. tract

3. Gastroenteritis

4. Hepatitis

5. STDs

6. Hemorrhagic fevers

 

Term
What is the difference between cytopathology and immunopathology? 
Definition

Cytopathology = Branch of pathology that studies and diagnoses diseases on the cellular level.

 

Immunopathology = Branch of medication that deals with the immune response associated w/the disease.  It includes the study of  the pathology of an organism, organ system, or disease w/ respect to the immunity/response.

Term
T/F: Rubella is caused by cytopathology.
Definition
False; it is not cytopathic (CPE) so the infection does not end in cell lysis.
Term
How many different types of Hepatitis are there?  Which is considered to be Serum Hepatitis? What about Infectious hepatitis?
Definition

A = Infectious Hepatitis

B = Serum Hepatitis

C

D

E

Term
These forms of Hepatitis are transmitted via percutaneous and permucosal.
Definition
Type B, C and D
Term
These forms of Hepatitis is transmitted via fecal-oral route.
Definition
A and E
Term
Which types of Hepatitis virus can lead to a chronic infection?
Definition
B, C, and D
Term
Out of all the Hepatitis types, which is ones  do not have a vaccine available to it?
Definition
Hepatitis C and E
Term
Which types of Hepatitis are associated with liver cancer?
Definition
Hep. B and C
Term
This type of Hepatitis has a reverse transcriptase, DNA Poly. and RNAse H.  Also has ds and ss DNA and is in an enveloped icosahedron.
Definition
Hep. B
Term
What are the modes of transmission for Hep. B?
Definition

1. Sexual

2. Parenteral injecting

3. Perinatal

Term
Where is the [M+] of Hep. B the highest in the body?
Definition
In blood, serum, wound exudates
Term
How can you prevent Hep. B?
Definition

1. Prevent perinatal HBV transmission

2. Routine vaccines for all infants

3. Vaccinate

Term
Hep. C is in the _______________ family and has _________________ genome.
Definition

Flaviviridae

+ss RNA

Term
How is Hep. C transmitted?
Definition

1. Blood transfusions

2. IV drug users

3. Sex

Term
T/F: Only Hep. B is associated with liver cancer.
Definition
False; Hep. B and C are associated with liver cancer
Term
What does Percutaneous and permucosal mean? Both Hep. B and C undergo this type of route of transmission.
Definition

Percutaneous

1. Injecting drug use

2. Transfusion

3. Contaminated equipment

4. Needlestick

5. Clotting factors b4 viral inactivation

 

Permucosal

1. Perinatal

2. Sexually

Term
Which route of transmission of Hep. C is the most common?
Definition
Injection from drug users
Term
What are some nosocmial transmission of Hep. C?
Definition

1. Contaminated equipment

2. Unsfae injection practices such as multiple dose medication vials

Term
When does perinatal transmission of Hep. C occur?
Definition

Only when women HCV-RNA positive at delivery

 

(higher incidence in HIV women)

Term
T/F: Men to men is the more effiecient sexual transmission of Hep. C.
Definition
False; male to female transmissio more efficient.  (indicative of sexual transmission)
Term
Which type of transmission of Hep. C accounts for 15-20% of acute and chronic infections in the U.S.  Also serves as a large chronic reservoir that provides hihger risk.
Definition
Sexually transmitted
Term
Can household transmission of Hep. C occur? If so provide an example how?
Definition
Yes, it can.  Sharing contaminated razors, toothbrushes, etc.
Term
How can you prevent Hep. C?
Definition

1. Avoid direct exposure to blood

2. Cover cuts and sores on skin

3. Do not share items that may have blood on them

4. Do not donate blood, body organs, etc

Term
T/F: Hep. C can be transmitted by kissing.
Definition
False; not spread by kissing, hugging, sneezing, coughing, sharing utensils
Term
What are some ways to prevent sexual transmission of Hep. C?
Definition

1. Use condoms

2. Limit # of partners

3. Get vaccinated against Hep. B

 

Term
What can remove the envelope of Hep. B?
Definition
Alcohol
Term
Out of all the Hep. types, which one is considered to be a retrovirus?
Definition

Hep. B

It has reverse transcriptase

Term
Provide an example of a contaminated equipment and unsafe injection practice that contribute to the nosocomial transmission of Hep. C.
Definition

Contaminated equip = Hemodialysis

 

Unsafe injection = plasmapheresis

Term
What 2 drugs when co-administered together help to treat Hep. C?
Definition
Interferon and Ribavirin
Term
What are important features of Hep C transmission via injecting drug use?
Definition

1. Hihgly efficient amoung injection drug users

2. Rapidly acquired after initiation

3. 4x more common then HIV

5. Prevalence 60-90% after 5 years

Term
Ribavirin is a analogue of ___________, with an incomplete base ring and an available 3'-OH grp.
Definition
Guanosine
Term
What are the sites of activity for Ribavirin?
Definition

1. Inhibits nucleoside biosynthesis

2. Inhibits capping of mRNA

3. Inhibits RNA Poly.

Term
Which Hep. (B or C) has more cases of symptomatic infections?  Which has the most cases of death from chronic liver disease?
Definition

Sympt = B (70K-160K  vs 3K- 54K)

 

Liver = C (8K-10K vs 5K-6K)

Term
Describe the Herpes Virus structure.
Definition

1. Enveloped icosahedral capsid 100 nm

2. 9 Glycoproteins

3. 30 structural proteins, but codes for 120

4. Tegument is amorphous

5. No common family antigen

Term
What are the 3 subfamilies of Herpesviridae?
Definition

1. Alphaherpsesvirinae

2. Betaherpesvirinae

3. Gammaherpesvirinae

Term
Subfamily Alphaherpresvirinae include which 2 genus? What virus does each genus include?
Definition

1. Genus Simplex virus = HSV1 and 2, B virus

2. Genus Varicella virus = varicella-zoster virus (chicken pox)

Term
The subfamily Betaherpesvirinae includes these 2 genus?
Definition

Genus Cytomegalovirus

Genus Roseolovirus

Term
What genus does the human herpes 6 and 7 belong to?
Definition
Genus Roseolovirus
Term
Which subfamily of Herpres includes the genus Lymphocyrptovirus? And is associated with the Epstein-Barr virus?
Definition
Subfamily Gammaherpesvirus
Term
The herpes virus had ___________________ DNA and naked DNA is ____________.
Definition

Double stranded linear

infectious

Term

AlphaHerpes is _____________-tropic

BetaHerpes is ________________ tropic

Gammaherpes is ______________-tropic

Definition

Neuro

Salivary gland

Lympho

Term
Describe the multiplication cycle of the Herpes virus.
Definition

1. Attachment - glycoproteins on viral envelope fuses with cell P.M.

2. Penetration - direct or endocytosis

3. Envelopes are acquired at inner nuclear membrane

4. Virions are released by reverse phagocytosis

5. Cell is not killed, but the functions are taken over by the virus

Term
When does latency of the Herpes virus occur?
Definition
With persistant infected cells in which no infectious virus is formed because the multiplication cycle is stopped at some stage.
Term
What are some characteristics of HSV1?
Definition

1. Fever blisters

2. Occurs early in life

3. Primary infection is 8-10 days

4. Latent infection is asymptomatic

 

Term
In HSV1 where does the viral DNA reside?
Definition
In the sensory ganglia
Term
When do recurrent infections occur in HSV1?
Definition
When the virus replicates and travels down the nerve fiber to infect epithelial cells.
Term
HSV2 is sexually transmitted. Where does the virus reside during latency?
Definition

In the nerves of the lower back

(sacral plexus)

Term
When does recurrent infections occur in HSV2?
Definition
5 or more times per year
Term
T/F: Prego women cannot transmit HSV2 during childbirth.
Definition
False, they can
Term
List the viral syndromes caused by HSV1.
Definition

1. Encephalitis

2. Keatoconjunctivitis

3. Pharyngitis

4. Esophaitis

5. Gladiatorum

6. Oral

7. Genital

8. Whitlow

Term
List the viral syndromes caused by HSV2.
Definition

1. Meningitis

2. Oral

3. Pharyngitis

4. Genital

5. Perianal

6. Whitlow

Term
When it comes to the brain, HSV1 causes ________________whereas HSV2 causes ____________________.
Definition

Encephalitis

Meningitis

Term
What are some major characteristics of the Varicella-zoster virus?
Definition

1. Spread by resp. tract

2. Chicken pox = seasonal epidemics

3. Vesicular rash w/systemic infection

4. 2-2 1/2 wks long infection cycle

5. More severe in adults

6. Recurrent infection occurs

Term
Recurrent infections of varicella-zoster virus is called ___________ and is localized to a ___________.
Definition

Shingles

Specific nerve

Term
What are some major characteristics of Cytomeglavirus (CMV)?
Definition

1. Infects and causes no obvious disease

2. Prego can abort fetus

3. Transmitted by saliva

4. Virus secreted in milk, saliva and semen

5. Major problem in immunosuppressed peeps

Term
A primary infection of the EBV causes ________________and ________% of people over 40 carry this virus.
Definition

Mononucleosis

95%

Term
Which herpes virus family member causes cancer?
Definition

HHV-8 is associated with Kaposi's sarcoma in AIDS patients

 

EBV is associated with Burkitt's lymphoma in AIDS patients and related w/ nasopharngeal carinoma in Africa

Term
What does Togaviridae mean?
Definition
Covered virusees
Term
What are the 3 genera associated with Togaviridae? Which is the cause of german measles?
Definition

1. Alphavirus

2. Rubivirus = causes Measles

3. Arteriviruses

Term
Unlike other togavirus infections, Rubella causes a _____________ and can spread by ________.
Definition

Respiratory illness

Aerosols

Term
T/F:  There is an insect vector with Rubella.
Definition
False; none
Term
Why is Rubella dangerous to prego women?
Definition
If mom does not have Ab to Rubella virus (from prior infection or vaccine), then virus can replicate in placenta and spread to fetal blood supply.
Term
What are some syndromes associated with congential infection of Rubella?
Definition

1. Cataracts

2. Mental retardation

3. Deafness

Term
What are some important features of Paramyxoviridae family of viruses?
Definition

1. Encased by a fragile lipid envelope

2. Nonsegmented (-) sensed ssRNA w/ 6-10 genes separated by noncoding termination, polyadenylation and initiation signals.

3. Replication occurs in the cytoplasm

 

Term
During viral replication of the family Paramyxovivridae, what does the virion attach to and how?
Definition
Attaches to sialoglycoprotein or glycolipid receptor by the envelope glycoprotein
Term
Which 2 membrane glycoproteins are key to the pathogenicity of all paramyxoviruses?
Definition

1. H, HN or G = glycoproteins mediate cell attachment

2. F(fusion) protein = has 3 functions

Term
What do the envelope glycoproteins H, HN stand for?
Definition

H = Hemagglutinin

HN = Neuraminidase

Term
What are the 3 functions of the F (fusion) protein in all paramyxoviruses?
Definition

1. Enables virus  to fuse to cell to form syncytia

2. Enable viral penetration by fusion of viral envelope w/ P.M.

3. Allows direct intercellular spread by cell to cell fusion (can now evade the bodys circulating Ab's, and allow transfer of infectious nucleocapsids to nearby cells)

Term
What is the body's cellular immunity response to paramyxoviruses?
Definition
Elicite a neutralizing Ab that inhibts adsorption of virus to cell receptors, thus inhibiting the infection. 
Term
What occurs after 6 days with Measles?
Definition
Virus spreads to all epithelial surfaces from the local blood vessels. (Viremia)
Term
What contributes to the respiratory damage, fever and early symptoms seen with Measles?
Definition
The immune system
Term
What immunity/vaccine is there for Measles?
Definition

1. Natural immunity against reinfection is effective

2. Passive immunization for the unimmunized (administer IgG)

3. Live vaccine

Term
T/F:  Severity of measles is affected by young age, low socioeconomic status and malnutrition.
Definition
True
Term
List some complications that can occur with Measles.
Definition

1. Subacute Sclerosing Panencephalitis

2. Subacute Measles Encephalitis

3. Acute Postinfectious Measles Encephalitis

Term
Why is Subacute Scelrosing Panencephalitis (comp. of Measles) fatal?
Definition
Manifests years after acute disease and fatal because of the slow spread of the virus into the brain.
Term
Why does Subacute Measles Encephalitis occur only in immunocompromised children?
Definition
Becuase there bodies fail to eliminate virus-infected cells as the body lack cytotoxic T cells. (CD8)
Term
Out of the 3 Measles complications that can occur, which is the most dangerous affecting 1 in 1000 older children. With a fatality of 15%.?
Definition
Acute Postinfectious Measles Encephalitis
Term
How are Mumps transmitted?
Definition
By saliva or other respiratory fluids
Term
What are some clinical features of Mumps?
Definition

1. Distorted face

2. Edematous enlargement of the salivary glands

3. Infants often asymptomatic or as a resp. infection.

Term
What complications can occur with Mumps?
Definition
Mumps Encephalitis that can result in unilateral nerve deafness
Term
_____________________ provides protective levels of the Ab by a single injection for at least 90% of those injected over a 20 yr period.  This decreased Mumps by 98%.
Definition
MMR vaccine
Term
What are the common features of families in the order Mononegavirales?
Definition

1. Non-segmented, (-) sensed ssRNA

2. Helical nucleocapsid

3. Virion associated RNA-dependent RNA Poly

4. Similar gene order

5. Single 3' promoter

Term
Which families are classified within the order Mononegavirales; which means they have common features of it.
Definition

Filoviridae = Ebola

Paramyxoviridae = Measles, mumps

Rhabdoviridae = Rabies

Term
What is some important features of the rabies virus?
Definition

1. Can infect all warm blooded animals

2. Causes acute, contagious infection of the CNS

3. 100% fatal once symptoms show

4. Occurs worldwide except Hawaii, Japan, Great Britian and smaller islands

Term
What are the principles rabies hosts today?
Definition
Wild carnivores and bats infected with several virus variants
Term
What are the vectors of transmission of the rabies virus?
Definition

1. Bite/scratch of an infected animal (99% of cases worldwide)

2. Aerosol transmission from a bat

3. Tissue transplants from infected human (eyes)

Term
T/F:  There is no viremia with the rabies virus.
Definition
True
Term
What is the course action of the rabies virus in humans?
Definition

1. Enters vody and travels w/in neurons to the CNS

2. Causes encephalitis in the brain

3. Virus travels down the nerves and multiplies in many diff. organs

 

Term
Which glands are the most important in the spread of the rabies virus from animal to humans?
Definition
Salivary glands
Term
What are some symptoms of Rabies?
Definition

1. Early = nonspecific includes fever, headache, tiredness, etc

2. Progesses = Insomnia, anxiety, confusion, paralysis, hallucinations, hypersalivation, hydrophobia, hard to swallow

3. Late = Delirium, coma, Death

Term
Which is the most definitive means of dignosis of Rabies?
Definition
Virus cultivation
Term
What vaccines are available for Rabies?
Definition

1. Preexposure Prophylaxis

2. Postexposure Prophylaxis

Term
Who should get the preexposure prophalyaxis for Rabies?
Definition
Labworkers, vets, wildlife officers, animal handlers (people at high risk)
Term
Preexposure prophylaxis for Rabies is an ____________ immunization with cell culture vaccine.
Definition
Active
Term
Which human disease is the only one that can be prevented by postexposure vaccination?
Definition
Rabies
Term
How many does of HDCV should be given for PEP of Rabies and prompt administration of what?
Definition

5 doses

Admin Rabies Immune Globulin

Term
________% mortality if treatment is given before onset of symptoms associated with Rabies virus.
Definition
0%
Term
What non-pharmacological treatment seems to reduce the spread of the Rabies virus.
Definition
Thorough wound cleansing
Term
What family does the Rotavirus belong to?
Definition
Family Reoviridae
Term
What are some important features of the Rotavirus?
Definition

1. Wheel shaped, 70 nm

2. 2 concentric icosahedral capsids surrounding an inner core

3. dsRNA, 11 segments each coding for a viral protein

4. Non-eveloped

Term
Why is the Rotavirus hard to make a vaccine for?
Definition

It has 6 serogroups (A-F)

 

Group A is the most common in humans

Term
What is the pathogenesis of the Rotavirus?
Definition

1. Infects intestinal cells and kills them

2. Initial infection most severe

3. Absorptive surface of intestine is reduced

4. Fluid accumulation in lumen = diarrhea

5. Disease is self limiting

6. Dehydration problems

Term
Which Ig is protective against Rotavirus?
Definition
IgA in colostrum (breast milk)
Term
A Rotavirus infection stimulates which Ig's?
Definition

Secretory IgA

Neutralizing IgG

Term
T/F: Maternal IgG is protective against Rotavirus.
Definition
False; no protection
Term
What is the route of transmission for Rotavirus?
Definition

Fecal-oral

(highly contagious)

 

Can survive for hrs on hands and days on surfaces!

Term
What are some clinical features of the Rotavirus?
Definition

1. 1-3 day incubation period

2. May be asymptomatic

3. Mild to severe

4. Death due to dehydration and electrolyte loss

5. Fever, vomitting, watery diarrhea

6. Lasts 3-9 days

Term
What is the common treatment for Rotavirus?
Definition

Oral Rehydration - glucose, H2O, electrolytes

If severe, IV fluid replacement

Term
What is the most common cause of gastroenteritis in children?
Definition
Group A Rotavirus
Term
How can you prevent Rotavirus?
Definition

1. Good hygiene

2. Chemical disinfections

3. Breast feed newborns

4. Vaccinations*

Term
What is the problem with the vaccine RotaShield for Rotavirus?
Definition
Blocks the intestine (intussusception)
Term
This vaccine is 98% protective against severe Rotavirus gastroenterisits.  It is a live oral vaccine.
Definition
RotaTeq Vaccine
Term
What 3 syndromes can the Influenza virus infection cause?
Definition

1. Uncomplicated Rhinotracheitis

2. Respirtatory viral infection followed by bacterial pneumonia

3. Viral pneumonia

Term
What are some major characteristics of the flu virus?
Definition

1. Higher death in young and old (decline in cellular immunity)

2. Binds to clarithin coated pit--forms a coated vesicle

3. Needs a low pH to cause fusion to endosome and uncoat

4. RNA replication occurs in cytoplasm then to nucleus

Term
What is the mechanism of action of Amantadine and Rimantadine to treat Influenza virus?
Definition

1. Ion channel blockers that inhibit the replication of influenza virus by targeting M2 protein

2. Block acidifications of endosomes which inhibits the fusion

3. Since no fusion, release of viral RNA is prevented 

Term
What is the mechanism of action of Tamiflu against Influenza virus?
Definition
It is a neuramindase inhibitor designed to attack the structures of the Influenza viruses A and B, preventing the spread of the virus w/in the body.
Term
What are some general characteristics of Piconaviruses?
Definition

1. Small ~ 30nm

2. Naked icosahedral = Infectious

3. ssRNA

4. (+) sensed

5. Replication occurs in cytoplasm

6. Can go directly into cell and be translated

Term
What are some important features of enteroviruses?
Definition

1. Stable at pH 3 so can survive passage thru stomach

2. Spreads by fecal oral route

3. Multiplies in cytoplasm

4. Produces a large precursor protein that can undergo post tranlational cleavage

5. Cause variety of diseases

Term
What is ICAM-1?
Definition
Intracellular Adhesion Molecule-1
Term
What is ICAM-1 role in virus attachment to the host?
Definition
It is a specific cellular receptor that the Rhinovirus family attaches to.
Term
What is the difference btwn primary and secondary viremia?
Definition

Primary = initial spread of virus in the blood from the the first site of infection

 

Secondary = Primary viremia that now affects  organs such as the skin, brain, muscle, liver, & meninges

Term
What happens during Poliovirus replication?
Definition

1. Adsorption to specific receptors

2. Internalization in vesicles

3. Lowering of the pH in the vesicles

4. Exposure of Hydrophobic grps on the virus

Term
List the 4 stages of polio virus infections.
Definition

1. Alimentary phase

2. Lymphatic phase

3. Viremic phase

4. Neurological phase

Term
What is a major illness of poliovirus infection progression?
Definition

Meningitis (stiffness of neck or back)

Can lead to paralysis

Term
What is IPV? OPV?
Definition

Inactivated Polio Vaccine

Oral Polio Vaccine

Term
What was used to the kill the polio virus to use in the inactivated polio vaccine?
Definition
Formaldehyde
Term
Which one (IPV or OPV) does not produce nasal and duodenal IgA protection?
Definition
IPV
Term
What is Post-Polio Syndrome?
Definition

Peeps who survived polio show muscular weakness and paralysis many yrs after infection and recovery.

 

Term
How does Post-Polio Syndrome develop?
Definition

Caused by death of individual nerve terminals in the motor units that remain after the initial polio attack. 

Maybe due to possible deterioration of nerves that are required to function for damanged nerves. (degeneration of motor neurons)

Term
Which type of meningitis is more common?
Definition
Viral
Term
List the viruses that cause viral meningitis.
Definition

1. Measles

2. Mumps

3. Enterviruses (Polio, Cox B and Cox A7/9)

4. HSV

Term
T/F:  Viral Meningitis is more severe than bacterial and recovery is almost none.
Definition
False; recovery is almost always complete and is less severe. (the above describes Bacterial)
Term
How is Viral Meningitis spread?
Definition
By coughing, sneezing and poor hygiene
Term
Can you use antibiotics for viral meningitis treatment?
Definition
No
Term
Is there a cure for Post-Polio Syndrome?
Definition
No, can treat the symptoms such as muscle weakness
Term
By the end of 2007, how many people had HIV? How many died?
Definition

33 million had it

2 million died from it

Term
 What are the clad, groups, and subtypes of HIV?
Definition

Groups=

 M (Major)

 N (Non-O/ Non-M)

O (Outlier)

 

Clads = A, B, C, D, H, G, J, K

 

Subtypes = look at figure

Term
How can HIV be transmitted?
Definition

1. Sex

2. Inoculation of infected blood/blood products

3. Mother to child

Term
HIV enters via mucosal linings during sexual contact, the first cells to become infected are ___________________. 
Definition
Mucosal Dendritic cells (MDC)
Term
Can you transmit HIV during nursing, if it is infected milk?
Definition

Yes

Transmission can occur before, during or after birth

Term
What is the likelihood of infection after a single exposure for the 3 routes of transmission of HIV?
Definition

Sex = 0.01-1.0%

Blood Transfusion = >90%

Mom = 12-50%

Term
Globaly, which route of transmission has the highest frequency although it is the least efficient route of transmission?
Definition

Sexual contact.

Likihood after 1st exposure = 0.1-1%, but globaly accounts for 65-80 (73%) % of all cases

Term
Which route of HIV transmission is the most effective?
Definition
Blood transfusion. >90% likelihood of infection after single exposure
Term
Which type of heterosexual transmission is the greatest?
Definition
2x-5x risk from male:female>> female:male
Term
What are some features of the HIV structure?
Definition

1. Reverse transcritpase that converts ssRNA to dsDNA

2. Has integrase that allows it genome to get into host DNA

3. Viral envelope proteins

4. Has a viral core w/proteins (M protein, Capsid, Nucleoprotein)

5. Accessory proteins

Term
What immune response occurs during the primary infection, clinical latency, Symptomatic stage of an HIV infection?
Definition

Primary = Slight increase in the # of CD8+ T cells  in wk 6, but returns back down by wk 9.

CD4+ T cells decrease

Anti-gp120 dramatically increases from 0.

 

Clinical = CD8, CD4 and Anti-gp stay fairly the same, hence the latency. This occurs for ~ 6yrs

 

Symptomatic = Slight decrease in Anti-gp, Decrease in 1/2 # of CD8

Dramatic decline in CD4 in 2 yrs. By year 8 nearly 0 CD4 T cells. This is when AIDs will develop

Term
After how many years of HIV infection, will AIDs develop in? What is nearly 0?
Definition

After 8 yrs

CD4 T cells are nearly 0 at this time.

Term
What is the pathogenesis of HIV?
Definition

1. High turnover of HIV and infected CD4 T cell loads

2. Persistant Immune activation

3. Destruction of host immune system

Term
What is persistant immune activation that occurs with HIV infection?
Definition
Exhaustion and death of immune cells
Term
What 4 symptoms of an acute HIV infection did he say to remember?
Definition

1. Fever

2. Lymphadenopathy (enlarged lympth nodes)

3. Pharyngitis

4. Rash

Term
During which clinical stage of HIV, has the highest plasma vRNA, Infectious particles, and infected PBMC?
Definition

During the Acute infection

vRNA = 5 x 10^6

IP = 2,500

HIV-PBMC = >30,000

Term
According to the CDC, a CD4+ T amount of < _____________ is classified as having AIDs.
Definition
400
Term
Describe the replication cycle for HIV.
Definition

1. Adsorption to specific receptor

2. Penetration

3. Reverse transcriptase

4. vRNA transit

5. Integration into host DNA

6. Transcription

7. Transcript processsing

8. Translation/ Post translational processing

9. Capsid assembly/ budding

10. Capsid processing

Term
Which steps of the HIV replication cycle can therapy work on to prevent the disease?
Definition

1. Antibodies to prevent attachment

2. Fusion Protein inhibitor

3. RT Inhibitors, so cant make viral DNA

4. Integrase inhibitor so cant incorportate viral DNA into host DNA

5. Protease inhibitors so no posst translational processing

6. Zinc finger inhibitors to stop capsid assembly and processing

Term
What is important about Anti-HIV nucleoside Analogs?
Definition
They look similar to the nucleotides so they get incorporated into the DNA, but they dont function properly.  They prevent further elongation of the vDNA.
Term
How do Non-nucleoside reverse transcriptase inhibitors work?
Definition
Directly bind to the enzyme and interefers with the enzyme functions. Cant convert to viral dsDNA.
Term
What is HAART?
Definition

Highly Active Anti-Retroviral Therapy

 

Many anti-HIV drugs to treat HIV+ peeps.

Usually includes 1 NS Analog, 1 protease inhibitor and a non-nucleoside RT inhbitor or another NS analog

Term
What precursor does viral protease create? What things arise from this precursor?
Definition

Gag-Pol precursor

 

Capsid

Matrix

Nucleoprotein

Protease

RT

Integrase

Term
What precursor arises from a cellular protease during HIV post translational processing?  Then what things can that precursor make?
Definition

Env Precursor

 

Surface Env

Transmembrane

Term
What do HIV protease inhibitors do?
Definition
They prevent the HIV protease from cleaving the Gag-Pol precusor polyproteins into the individual viral structural proteins (capsid, matrix, nucleoprotein) and viral enzymes (RT, PR, IN)
Term
What evaluations should be performed before starting treatement for HIV?
Definition

1. Complete history and physical

2. CBC and chemistry profile (include transaminases and lipid)

3. CD4+ T cell count

4. Plasma HIV RNA measurement

Term
What are the goals of HIV therapy?
Definition

1. Maximal and durable suppression of virus load

2. Restoration or preservation of immunologic function

3. Improvement of quality of life

4. Reduction of HIV related morbidity and mortality

Term
________________ uses probes to detect selected mutations that are known to confer drug resistance.
Definition
Genotyping Resistance tests
Term
___________________ measures the ability of the virus to grow in various concentrations of antiretroviral drugs.
Definition
Phenotyping Resistance Tests
Term
Why is it important to thoroughly evaluate an HIV patient before starting treatment?
Definition

To decide whether or not treatment is needed.

If has a/symptomatic AIDs then treat.

 If Asymptomatic HIV then treatment should be offered (CD4 200-350).

If CD4 > 350 w/ RT-PCR > 55K then varies on treatment option. Now have >30% chance of getting AIDs.

If CD4 >350 but RT-PCR <55K then many would defer treatment. 

Term
What are the major reasons for treatment failure in HIV patients?
Definition

1. Resistance to drug = 70%

2. Low Drug [M+] at the viral replication site = 25%

3. Progressive decline of the immune system

Term
What are causes of treatment regimen failure in HIV peeps?
Definition

1. Patient factors such as age, co morbidities, etc

2. No compliance, miss clinical appts

3. Drug side effects and toxicity

4. Pharmacokinetics factors such as metabolism is fast, food/fasting, drug-drug interactions, etc

5. Potency of antiretroviral regimen

Term

When does resistance occur for the following drugs that treat HIV?

NRTIs = Nucleoside RT Inhibitors

PIs = Protease inhibitors

NNRTs = Non nucleoside RT Inhibitors

Definition

NRTIs = 6-12 months

PIs = 2-3 months

NNRTIs = days-weeks

Term
When do you change an antiretroviral regimen for suspected drug failure?
Definition

When 1 or more of the following occur:

1. Incomplete virologic response (failure to decrease HIV RNA)

2. Virologic rebound (Re-appearance of viremia after suppression. Shows resistance)

3. Immunologic failure (Persistant decline in CD4 T cell count)

4. Clinical failures (deterioration after 3 mo)

Term
What is the global distribution of HIV-1 subtypes?
Definition

Highest cases were in Sub-Saharan Africa (Accounts for 70% of all cases and about 58% of all women in Africa have it), SE Asia and South America.

In 2003, the global total = 40 million have it and 3 million deaths from it and 5 million new infections.

 

Term
Why is it so difficult to develop a vaccine for HIV?
Definition

RT is a high error prone enzyme that causes many mutations thus variations. 

The disease can spread by many different routes.

There are many different Clads and subtypes of HIV, hard to make 1 that fits all.  All have diff. properties/genes

Term
What is important about AZT?
Definition
It is a nucleoside analog. So it looks like regular NT but instead of 3'OH it has a N3.  This causes chain termination so no further elongation of viral DNA.
Term
What is important about RT?
Definition
It is the viruses reverse transcriptase.  This allows ssRNA to become dsDNA that way it can then go into the hosts DNA.
Term
What stage of HIV infection has the highest titer of virus?
Definition
Acute (Primary) infection
Term
During which stage does persistant immune activation occur?
Definition
During the Primary infection where your body is constantly trying to fight off the virus
Term
What is cross resistance?
Definition
If develop for resistance to 1 drug then become resistant to other drugs that have a similar mechanism of action (ex. if in same drug class)
Term
Which HIV drugs has the highest frequency of cross resistance?
Definition
NNRTI > PIs > NRTI
Term
What is meant by Acute Fulminant Hepatitis?
Definition
Acute liver failure
Term
Which Hepatitis virus causes Fulminant Hepatitis?
Definition

Hep B.

 

(I'm not too sure, Hep A has 100 deaths a yr from this and Hep D has 35 deaths a yr. But Hep B is 150 deaths a year).

Term
Which herpes virus is more problematic for AIDS patients?
Definition
Herpes Simplex
Term
What are the 2 main routes by which enteroviruses may reach blood?
Definition

1. Fecal oral route (ingested)

2. Respiratory

 

(I'm like 90% positive about this)

Term
Once an enterovirus is in the blood, where does it go after that?
Definition

Can go to the CNS and affect the brain.

Or can cause secondary viremia and affect other organs such as the skin, liver, muscle.

Term
What is the % of people who previously had Polio will develop Post Polio Syndrome? And when do symptoms appear?
Definition

1. 25-50% of people

2. Symptoms occur 15-30 yrs after the original infection

Term
The highest number of Hep. C positive peeps are found among ____________ and _____________.
Definition
Black and Hispanic
Term
What are some features of fungi?
Definition

1. Affected by Geography & environment ( with damp areas)

2. Associated w/ soil

3. Produce endospores for reproduction

4. Are usually inhaled

5. Recycle organics

6. Opportunistic

7. Major antibiotic producers

6.

Term
Fungi can be divided into ______________ and _______________.
Definition

Yeast

Mold

Term
Yeasts are typically ____________ and reproduce by ____________. Give an example of one.
Definition

Round/oval

Budding

 

Ex: Candida

Term
Molds are composed of ____________ that grow _______________ and _____________ extensions.
Definition

Hyphae

Branching

Longitudinal

Term
Give an example of a mold.
Definition
Aspergillus
Term
T/F: Some fungi are dimorphic; both yeast and mold like
Definition
True
Term
T/F: Candida is part of the normal flora.
Definition
True
Term
What is responsible for one of the first manifestations of AIDs?
Definition
Candida infections
Term
What infections can Candida cause?
Definition

1. Thrush

2. Yeast infection

3. Skin and Mucosal infections

Term
Thrush is characterized by white pustules in the ___________ and _____________.
Definition
Mouth and throat
Term
Give an example of a dimorphic fungus.
Definition
Histoplasma
Term
Where does the fungus Histoplasma reside and how is it acquired?
Definition

Resides inside macrophages and neutrophils.

 

Acquired by inhalation

Term
Do antibiotics work against fungi?
Definition
No.  Use Amphotericin B
Term
________________ are molds and the causative agent of ringworm.
Definition
Dermatophytes
Term
If the dermatophytes primarily infects animals it is called ______________, if it affects only humans then it is called _________.
Definition

Zoophilic

Antrhopophilic

Term
Dermatophytosis tend to infect which kinds of sites?
Definition

Scalp

Feet

Skin

Groin

Term
This dermatophytes primarly affects the groin area and causes Jock itch.
Definition
Tinea Cruris
Term
Which dermatophyte causes ringworm in legs and trunks?
Definition
Tenia Corporis
Term
____________ causes ringworm of the scalp.
Definition
Tinea Capatis
Term
Which dermatophytes causes a fungal infection of the nails.
Definition
Onychomycosis
Term
Tenia Pedis is seen in young teens and is common in bathing facilities.  It affects ____________ and the main symptom is __________.
Definition

Toes

Itching

Term
How does the mold Aspergillus enter the body?
Definition
Inhalation of spores. But can also enter thru traumatized skin
Term
What are some features of Protozonal infections?
Definition

1. Eukaryotic, unicellular

2. In 2 forms: cysts or trophoziote

3. Classified based on there locomation

4. Fecal-oral route

5. H2O borne also

6. Anaerobic

Term
Trichomonas vaginalis is a _____________ parasite with no known cyst form.
Definition
Flagellated
Term
T/F: Men cannot get Trichomanas Vaginalis.
Definition
False; they are also infected
Term
The cell wall of fungis have _______________ which is a target for anti-fungal drugs.
Definition
Ergosterol
Term
Which form of a parasite is infectious? which is the growing form?
Definition

Infectious = Cyst form

Growing = Trophozoite

Term
What oral agent is used when scalp and nail infections dont respond to topical therapy?
Definition
Griseofulvin
Term
What is the significance of Metroniazide in treating anaerobic infections?
Definition
It forms an "electron sink" and inhibits the anerobic respiration and the double helix structure
Term
Which protozoan infection could be considered an STD?
Definition
Scabies
Term
What is Scabies?
Definition
Highly contagious parasitic skin infection caused by mites that are host specific to humans and completes its entire life cycle on human skin.
Term
What are important clinical features of infection by Histoplasmosis?
Definition

1. Severe infections resemble ARDS

2. Causes large pulmonary lesions that become nodules = Histoplasmoma

3. Granuolmatosis and fibrosis that infects lymph nodes

4. If chronic have diseased upper lobes of lung

5. Progressive is usually fatal

6. Can infect choroid

7. African version selectively affects skin, soft tissues and bone not lungs.

Term
Which body fluids have the lowest amount of Hep. B?
Definition

Urine

Feces

Sweat

Tears

Breastmilk

Term
Which body fluids have moderate amounts of Hep. B?
Definition

Semen

Vaginal

Saliva

Term
List some ways to prevent Scabies?
Definition

1. Wash bedding in very hot water (125 F)

2. Avoid sex w/ infected peeps

3. Dry clean clothing

4. Vacuum living room

5. Dont share clothes/towels/bedding

6. Notify school

Term
Malaria is caused by ______________, and use ________________ as there insect vector to transmit to humans.
Definition

Plasmodium

Female Anopheles Mosquitoes

Term
Which cycle in the mosquito is it when the protozoan turns into the cyst form?
Definition
During the Sporogonic cycle
Term
Once the cyst form of Malaria bites a human, what cycle does it enter and what organ does it affect?
Definition

Enters the Exo-Erythrocytic Cycle

 

It affects the liver

Term
What happens during the trophozoite form of Malaria?
Definition
The protozoan is in the liver. It ruptures and leaves the liver to go to the RBCs.  The RBCs can then rupture and regenerate the protozoan.
Term
During which stage of Malaria infection is responsible for clinical manifestations of the disease?
Definition
Erythrocytic Cycle
Term
_____________________ is the morphological form which develops in the mosquito salivary gland.  It is injected when the mosquito feeds.
Definition
Sporozoite (cyst form)
Term
What are the typical clinical manifestations of Malaria?
Definition

1. Recurrent high fever

2. Chills

3. Headache

4. Anemia

5. Splenomegaly

6. Weakness

Term
What can Malarial organism also cause, that will ultimately lead to death? Why does this occur?
Definition

Can cause Splenomegaly.

The Red pulp of the spleen is the cemetary for RBC.  The spleen enlarges because it has alot of dead RBCs.

Term
How many new infections of Malaria are there a yr and what is the best means of controlling mosquito pop.?
Definition

600 million/yr

Use DDT

Term
How many deaths per year are associated with Malaria?
Definition
3 million
Term
Which protozoan invades RBCs?
Definition
Malaria
Term
Which 2 protozoan infections are associated with HIV infection?
Definition

1. Leishmaniasis

2. Malaria

Term
Which protozoan infects Reticuloendothelial cells?
Definition
Visceral Leishmaniasis
Term
Which protozoan is the causative agent for Amoebiasis, and 100,000 deaths/yr?
Definition
Entamoeba Histolytica
Term
Which protozoan caused flask-shaped lesions in the colon and causes bloody diarrhea?
Definition
Entamoeba Histolytica
Term
What % of people w/E.Histolytica are asymptomatic?
Definition
85-90%
Term
How is E.Histolytica transmitted?
Definition

Fecal-ral

Sexual

Term
What are some important features of Giardiasis?
Definition

1.  (4pairs of flagella) Flagellated protozoan parasite

2. 1 celled organism

3. Lack ER, Mito, GA and Lyso

4. Protective outer shell

5. Anaerobic

6. Aerotolerant

Term
Cyst form of Giardia is ingested with contaminated water and food and is passed in ___________.
Definition
Feces
Term
What animal serves as a reservoir of Giardia?
Definition
Beavers
Term
________________ causes very distinct, smelly, greasy, frothy diarrhea.
Definition
Giardia Lamblia
Term
Which protozoan has a very low ID50 and cuases a diarrheal disease?
Definition
Cryptosporidium parvum
Term
How is Cryptosporidium spread?
Definition

Fecal oral

Water/food borne

Term
What are the 3 types of Cryptosporidiosis that can occur?
Definition

Intestinal

Pulmonary

tracheal

Term
How is Leishmaniasis transmitted?
Definition
Via the bite of female sand flies
Term
Which is the most severe form of Leishmaniasis and is related to HIV?
Definition
Visceral Leishmaniasis (VL)
Term
There is a _______% mortality rate in VL if untreated and __________% of adult cases are related to HIV.
Definition

100%

25-75%

Term
What is a possible outcome for G.Lamblia infection? And who is at risk for this disease?
Definition
Found in day cares. Can lead to chornic symdrome of diarrhea that contributes to malabsorption and weight loss. (35-70%)
Term
Which protozoans are capable of causing skin infections?
Definition
Leishmaniasis and Scabies
Term
Which protozoan can cause both a skin and systemic infection?
Definition
Leishmaniasis
Term
What are the signs and symptoms of Leishmaniasis infection?
Definition

1. Persistent fevers, may cycle

2. Night sweats

3. Fatigue

4. Weakness

5. Appetite loss

6. Weight loss

Term
What are the 3 basic principles of antimicrobial therapy?
Definition

1. Selective toxicity (kill organism not man)

2. Reach the site of infection at inhibitory [M+]

3. Penetrate and bind to target (avoid inactivation and extrusion)

Term
List the target sites/activities for Antibacterial agents (antibiotics).
Definition

1. Cell wall synthesis (we lack this)

2. Protein synthesis (ribosomes)

3. Nucleic acid synthesis

4. Cell membrane function

Term
What is murein?
Definition
Means cell wall composed of 2 monomers NAG and NAM that is cross linked.
Term
Which classes of antibiotics affect the cell wall synthesis?
Definition

1. Clycoserine

2. Glycopeptides

3. Bacitracin

4. Beta lactams

Term
What is the mechanism of action of Beta Lactam antibiotics?
Definition
Penicillin Binding Proteins (PBPs) are enzymes involved with cross linking bacterial cell wall components.  Beta Lactams bind to them and inhibit the enzyme from catalyzing the cross link. 
Term
What are the classes of antibiotics that target protein synthesis mechanism?
Definition

1. Aminoglycosides

2. Tetracyclines

3. Chloramphenicol

Term
List different Aminoglycosides.
Definition

1. Gentamicin

2. Streptomycin

3. Amikacin

4. Neomycin

Term
Penicillin is considered to be _________________ because it kills growing bacteria.
Definition
Bacteriostatic
Term
Why is it harder to achieve selective toxicity with drugs targeting viral diseases and eukaryotic diseases than prokaryotic?
Definition
The cells of viral and eukaryotic diseases are similar to the host.  Targeting these cells can accidentally damage the host cells also. 
Term
What is selective toxicity?
Definition
Exploiting differences in structure/metabolism of pathogens and host cells in order to kill the microrganism and not the human host.
Term
Most antibiotics acting upon the ribosome are ______________, but aminoglycosides are ____________.
Definition

Bacteriostatic

Bactericidal

Term
What are some general properties of Aminoglycosides?
Definition

1. Treatment for severe sepsis

2. Needs O2 for entry into cells

3. Fat insoluble = not absored orally

4. Toxic to kidney and inner ear

Term
What is the mechanism of action for Tetracyclines?
Definition
Inhibits protein synthesis by preventing amino acyl transfer RNA from entering the A site on the ribosome.
Term
How does Chloramphenicol inhibit protein synthesis?
Definition

It has a nitrobenzene nucleus that blocks peptidyl transferase blocking the protein synthesis.

 

(Bacteriostatic)

Term
What are some drugs that act on inhibiting precursor synthesis of nucleic acids?
Definition

1. Trimtethoprim

2. Sulfonamides

Term
_______________ is used as a DNA replication inhibitor because it affects _____________, so the bacteria is unable to 'pack' DNA into the cell.
Definition

Quinolones

DNA gyrase

Term
Which antimicrobial agent affects DNA-dependent RNA polymerase, thus blocks mRNA so no nucleic acid is made.
Definition
Rifamycins
Term
Which drugs affect cell membranes?
Definition

1. Azoles = no synthesis of ergosterol

2. Polyenes (Amp.B) = binds to sterols and causes leakage of components then causes cell death.

Term
What does Metronidazole do to DNA?
Definition
When it is reduced it can bind to DNA, oxidize it and then cause strand breakage.  Works for anerobic infections.
Term
How can resistance disseminate?
Definition

1. Chromosomally mediated resistance= mutant selection

2. Plasmid mediated resistance = spread of ressitance plasmid

3. Plamid mediated resistance on transposon = spread of resistance gene

Term
What is plasmid?
Definition
Molecules of DNA which replicate independenly of the bacterial chromosomes.
Term
What are some ways bacteria can make antibiotics ineffective?
Definition

They can physically and chemically remove the drug.

 

1. Alter target = lowers affinity for antibacterial

2. Alter the uptake = pump drug out of cell

3. Drug inactivation = enzyemes that kill the antibacterial agent

Term
How can humans prevent development of antibiotic resistance bacteria?
Definition

1. Dont dispense antibiotics w/out Rx

2. Control misuse of antibiotics

3. Antibiotic policies

4. Surveillance of use coupled w/ monitoring emerging patterns of resistance

5. Control use in industry

Term
Which organism is responsbile for stomach ulcers?
Definition
H.Pylori
Term
T/F:  H.Pylori and Strep. Mutans are not part of the normal flora.
Definition
False; both are in normal flora
Term
What are the virulence factors for H.Pylori?
Definition

1. Flagella

2. Adhesins (attaches to stomach lining)

3. Urease enzyme (neutralizes acid so bacteria can grow)

Term
How do you treat stomach ulcers?
Definition
Lifestyle changes and acid reducers
Term
What causes plaque and tooth decay?
Definition
Strep. Mutans
Term
How does Strep. Mutans soften enamel?
Definition

Bacteria can turn sucrose into Glucan (polymer).

Glucan allows the formation of biofilm.

Biofilm covers bacteria and provides anaerobic growing conditions for bacteria.

Fermentation occurs w/ sucrose.

This decreases pH

Decreased ph softens enamel

Term
T/F: Strep. Mutans have pilli for attachment.
Definition
True
Term
List viral infections for which a vaccine is available.
Definition

1. Hep A and B

2. Influenza

3. Measles, Mumps, Rubella (MMR)

4. Polio

5. Rabies

6. Smallpox

7. Varicella-Zoster

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