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22 Cards in this Set
- Front
- Back
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What are 3 normal functions of hepatocytes?
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1.Bilirubin uptake/bile secretion
2.Synthesis and secretion of serum proteins 3.Drug clearance 4.Cholesterol and lipoprotein metabolism 5.CHO metabolism and storage |
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How can hepatocyte damage be detected in the blood? In the excretory products?
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*elevated ALT/AST in the blood
*urine darkened due to the presence of bilirubin *feces pale due to reduced bile |
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What is the basic difference between acute and chronic hepatitis?
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The length of symptoms - acute is less than 6 months, while chronic is greater than 6 months.
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Other than the hepatitis viruses, what viral infections can present with liver inflammation?
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*Epstein-Barr virus
*CMV *herpes simplex *adenovirus *yellow fever virus |
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How do HAV and HEV leave the hepatocyte? What about HBV, HCV, and HDV? What does this mean in terms of transmission of the viruses?
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*HAV and HEV leave through the bile and thus are shed in the feces and spread by the fecal-oral route
*HBV, HCV, and HDV are secreted into the blood and thus are transmitted in most body fluids |
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What is the structure of the HAV virion? What is the sttructure of its genome?
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HAV consists of a single molecule of (+) ssRNA in a non-enveloped, icosahedral capsid.
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Give the families of the five hepatitis viruses.
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1.HAV - picorna
2.HBV - hepadna 3.HCV - flavi 4.HDV - delta 5.HEV - calici |
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How is the HAV genome translated? Describe the 5' region of this genome.
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*the virus is translated as a single long polyprotein which is then cleaved
*there is no cap at the 5' end of the virus, but there is an IRES in the 5' end for ribosome association *VPg is also present at the 5' end |
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How is the protease activity of HAV distinct from that of poliovirus?
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The HAV viral protease does not inactiavte host cell protein that associates with capped mRNA's (as does polio viral protease)
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What effect does translation of the HAV genome have on the host cell metabolism?
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Very little - there is no eveidence that this infection metaboolically overstresses the host hepatocyte.
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Put the following in order of appearance:
IgG Anti-HAV, IgM Anti-HAV, symptoms, serum ALT, fecal HAV Ag |
1.Fecal HAV Ag
2.serum ALT and symptoms 3.IgM Anti-HAV 4.IgG Anti-HAV |
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How is a HAV infection resolved? What are the long-term sequelae of such an infection?
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IgM and later IgG assist in what is primarily a cell-mediated immune response that clears infected hepatocytes. These are replaced by new hepatocytes. There are virtually no long-term effects, other than lifelong immunity.
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What animals serve as a reservoir for HAV? How is the diease spread?
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*HAV has no non-human reservoir
*spread is thru fecal-oral transmission |
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What factors make control of HAV difficult?
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The virus is very stable in the environment (no envelope) and the virus is shed in feces for two weeks prior to the onset of symptoms. Also peds may have subclinical or asymptomatic infections, but still spread the virus.
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Which of the hepatitis viruses have a vaccine?
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HAV and HBV
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What measures can be taken to prevent HAV? What treatments are available?
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*prevention through good hygiene and vaccine
*no medications *supportive treatment and possible use of pooled gamma globulin |
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What is the genomic structure of HEV? How is it translated?
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(+) ssRNA that has three ORF's and may be translated as a single polyprotein
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The course of infection by HEV is very similar to that of HAV, except that HEV may cause fulminant infection and high mortality is one segment of the population. Who are these patients?
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There is a 20% mortality associated with fulminant HEV in pregnant women.
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Recently there has been new concern about HEV in the US. What caused this concern?
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The discovery of an HEV-related virus in domestic pigs with at least one documented case of transmission to a human.
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Describe fulminant hepatitis.
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This really a subset of acute hepatits with extremely rapid onset and course, increased severity, and high mortality.
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Chronic hepatitis can progress through at least four stages - what are they?
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1.Chronic persistant hepatitis
2.Chronic acute hepatitis 3.Cirrhosis 4.Hepatocellular carcinoma |
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Name three populations especially at risk for HAV.
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1.Food handlers
2.Homosexual males 3.Persons in a daycare or institutional setting 4.Persons receiving blood products |
