Virology Flashcards

Question

HHV-5 (CMV): eye

Answer 1

* Pink eye due to adenovirus (HHV-5) infection * chorioretinitis associated w CMV in newborns * most prevalent viral cause of congenital disease * Affected newborns show: * small size, thrombocytopenia, microcephaly, intracerebral calcification, jaundice, hepatosplenomegaly (HSM), and rash

Answer 2

* Hep B, C, G, D * HIV * HTVL-1 * HHV-5 (CMV) * HHV-4 (EBV) * W. Nile encephalitis virus

Answer 3

* rounding * inclusion bodies * Ebola virus inection: liver inclusion bodies * GI hemorrhage due to CMV: stomah * cell lysis, necrosis, apoptosis * syncytia formation * transformation * Giant cells *

Answer 4

* HPV -\> cancers of cervix & oral cavity * HBV & HCV -\> HCC * EBV -\> Gastric cancer, nasopharyngeal carcinoma, non-Hodgkin's lymphoma, Hodgkin's lymphoma

Answer 5

* loss of growth control * reduced adhesion * motility * invasion * ability to form tumours * Transformed cells frequently exhibit chromosomal aberrations * Lytic stage -\> Late proteins Transformed -\> early proteins -\> stopped -\> then undetectable

Answer 6

* Papilloma: oncoproteins E6 & E7 * E6 modifies p53 & hTERT * E7 modifies pRB * Polyoma: large T and small T antigen * polyoma virus have ds circular DNA - both early and late proteins expressed during lytic - only late proteins expressed in transformation * Adenovirus: E1A and E1B * BK virus: Large T * SV-40: Large T

Answer 7

* \>90% of EBV-infected people intermittentl shed the virus for life (even asymptomatic) * approx. 70% of the US population infected by age 30 * causally associated w endemic Burkitt's lymphoma (AfBL), Hodgkin disease, nasopharygneal carcinoma (NPC) * has 3 potential outcomes: * replicate in B cells or epithelial cells permissive or EBV replication * cause latent infection of B cells in presence of competent T cellls -\> Downey cell association (atypical T cells, enlarged cell & nucleus) * stimulate and immortalize B cells * Note: both B- & T-cells required for antigenpresentation

Answer 8

* tumour of bv wall * rare in people not infected w HIV * common in HIV+ people frequently detected tumour in AIDS Pt * pink, red, or purple lesions on skin and mouth

Answer 9

* Merkel cell carcinoma (MCC) highly aggressive neuroendocrine carcinoma of skin w a high propensit of recurrence and metastasis * 5-year disease-specific survival rate ~60% * MCV associated w most MCC cases (subset of MCC, 20 - 30%, do not harbour MCV and apparently have a distinct pathoetiology)

Answer 10

* each of the hepatitis viruses infects and damages the liver * classic sx of jaundice and release of liver enzymes * spread by blood or needles, sex, and perinatally; also in tears, semen, vaginal. * median incubation period of ~ 3 mo, after which icteric sx start * chronic hep follows in 55 to 10% * 1/3 of world's pop has been infected w HBV -\> 1 to 2 million deaths/r * incidence of HBV is decreased (development, use HBV vaccine) * strict tissue tropism to liver * HBV produces HBx protein to regulate apoptosis, proliferation, genetic instability to stay in host liver and produce small amounts of virus continuously * can integrate into host chromosome

Answer 11

* HCV transmission -\> develop cancer 10 to 50 years (median 30 years) * flavivirus (class IV) w (+) ss RNA genome * Exception: only flavivirus not transmitted thru insects * continual liver repair, induction of cell growth during chronic HCV infection

Answer 12

* some retroviruses have oncogenes in addition to regular genes * retroviruses - particularly oncovirinae * Ex. HTLV-1 -\> leukemia * cause cancer after \>30 y latency * promote cell growth in more indirect ways than oncogene-encoding viruses * associated w non-neoplastic neurologic disorders and other disease * adult acute T-cell lymphocytic leukemia (ATLL) & HTLV-1 associated myelopathy (tropical spastic paraparesesis) * Tax: transcriptional regulator -\> activates promoters including IL-2 & IL-2R * integrates near cell growth-controlling genes

Answer 13

* viral infections: HTLV-1, Hep C, and EBV, increase the risk of developing non-Hodgkin's lymphoma

Answer 14

* produces the following proteins: * core to regulate apoptosis * NS2 -\> proliferation * N55B -\> genetic instability * HCV transmission -\> develop cancer: 10 to 50 years (median 30 years) * HCV is a flavivirus (class IV) w a (+) ss RNA genome * Exception: only flavivirus not transmitted thru insects * acute HCV infection can go 3 routes: * Recovery & clearance (15%) * Cirrhosis rapid onset (15%) * Persistent infection (70%) of which 40% asymptomatic leading to chronic hepatitis, further leading to * liver failure * cirrhosis * Primary hepatocellular carcinoma (PHC)

Answer 15

* altered (mutated) to non-pathogenic form * tropism altered -\> no longer grows at a site to cause disease * Polio (Sabin), MMR, Yellow fever, Rotavirus, Varicella

Answer 16

* rendered non-pathogenic usually by chemical treatment such as w formalin that cross-links viral proteins. * Ex. Hep A, Influenza, Polio (Salk) * influenza vaccine: trivalent inactivated vaccine (TIV), however live attenuated vaccine is more effective

Answer 17

* Virus Like Particles (VLPs) * HepB * Quadrivalent HPV 6/11/16/18 L1 VLP (Gardasil) * HPV vaccine * Recombinant L1 proteins that self-assemble into VLPs * Admin. before onset of sexual activity, then 2x after (~100%) protection from infection w vaccine HPV types. * Potential to prevent ~70% of cervical cancers, ~90% of genital warts.

Answer 18

2 ways: - take viral DNA, circularize into plasmid, plasmid coated w gold particles and injected - take viral gene and splice into another vector. ex. vaccinia virus

Answer 19

Herpessimplexvirus • Varicella-zostervirus • CMV • HIV * Influenza A and B viruses * RSV * HBV & HCV * Papillomavirus * Picornavirus

Answer 20

1. Recognition & attachment: Ab-receptor antagonists 2. Uncoating: Amantadine, Arildone, Rimantadine, Tromantadine 3. Transcription: interferon, antisense, oligomers 4. Replication: nuceloside analogues (guanosine), AZT, Acyclovir 5. Protein synthesis: interferon 6. Fusion: Tromantadine, Enfuvirtide 7. Assembly: protease inhibitors

Answer 21

nucleoside analogues: incorporated into viral genomes -\> inhibition of function of viral DNAP. * chain termination: analouges lack hydroxyl groups for linking of backbone, * Ex. Acyclovir for HHV-I & HHV-II: Guanosine analogue, must undergo TK-mediated phosphorylation (Acyclovir triphospate) * * Nucleoside inhibitors of RT * Ex. AZT * Ex2. ddl * * Non-nucleoside polymerase inhibitors * Ex. Nevirapine binds to various sites on enzyme

Answer 22

* Ex. protease inhibitors (Saquinavir) * block cleavage of polyproteins * HIV is dependent on proteolytic enzyme for full infectivity * Drug-resistant strains \> protease mutations

Answer 23

* Interferons: * IFN-alpha: active against many viral infections (Hep A, B, and C, HSV, HPV, and rhinovirs) * Imiquimod * TLR ligand, stimulates innate responses to attack the virus infection (HPV)

Answer 24

CART & Highly Active Antiviral Treatment (HAART) - multiple mechanisms to control viral diseases

Virology Flashcards

(48 cards)