Term
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Definition
| polyomaviridiae, along with BK virus and Simian Virus 40 |
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Term
| JCV is the opportunistic infectious agent of the fatal demyelinating disease ________. |
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Definition
| progressive multifocal leukoencephalopathy |
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Term
| What percent of the population has JCV? |
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Definition
| 80%, infection is thought to be subclinical and occur in early childhood |
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Term
| What percent of HIV-1 infected patients will exhibit neurological disorders? what percent will develop PML? |
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Definition
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Term
| What are the symptoms of PML? |
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Definition
| multiple neurologic signs and symptoms reflecting the multifocal areas of demyelination: motor weakness, visual disturbances including double vision, subcortical dementia, slowed motor function, limb paralysis, rigidity and sensory disturbances. |
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Term
| Where in the brain does PML develop? |
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Definition
| white matter of any part of the CNS including the brainstem and the cerebellum although the cerebral hemispheres are most commonly involved. For unknown reasons, the optic nerves and spinal cord are virtually never involved (helps with differential diagnosis) |
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Term
| What characterizes PML histopathologically? |
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Definition
| multiple areas of demyelination with axonal preservation, located in the sub-cortical white matter. Contain several enlarged oligodendrocytes with intranuclear eosinophilic inclusion bodies accompanied by a reactive astrocytosis. Astrocytes might be enlarged an bizzare with irregularly lobulated hyperchromatic nuclei. Perivascular cuffs of lymphocytes and microglial nodules can be found |
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Term
| Describe the JC virus genome: |
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Definition
| fxnally divided into 3 regions; regulatory (noncoding) region (viral origin of DNA replication and bidirectional promotor), early coding region and a late coding region. |
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Term
| Viral late genes of JCV encode... |
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Definition
| structural capsid proteins (VP-1, VP-2, and VP-3), as well as the accessory protein Agno |
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Term
| How does JCV destroy myelin sheath? |
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Definition
| it infects the oligodendrocyte, replicates, lyses and destroys the oligodendrocyte and thereby the myelin sheath |
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Term
| Describe the T antigen of JC virus. |
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Definition
| 79% homology with SV40 T antigen. Large. Nuclear localization signal, regions responsible for DNA binding, pol, helicase, ATPase activity. |
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Term
| What is the most highly conserved domain among all polyomavirus T antigens? What is the significance of this? |
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Definition
| ATPase domain which partially overlapse with the region important for complex formation with the cellulartumor suppressor protein, p53 |
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Term
| Is T antigen an early or late protein? |
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Definition
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Term
| What is the function of T-antigen? |
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Definition
| multifunctional protein that contains ATPase and helicase activity and can bind to DNA, alpha polymerase and cell cycle regulators such as p53 and Rb |
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Term
| What diseases does JCV cause in animal models? |
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Definition
| tumors of neuroendocrine origin |
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Term
| What is the only polyomavirus that induces tumor formation in non-humna primates? |
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Definition
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Term
| T/F T antigen in teh absence of JC virus and therefore viral replication, can alter myelin formation to induce dysmelination. |
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Definition
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Term
| Is JCV associated with human brian tumors? |
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Definition
| there have been several reports of this |
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Term
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Definition
| a member of the inhibitors of apoptosis family which is abundantly expressed during embryonic development in proliferating tissues, but is normally absent. There is increased expression in the intranuclear includsion bodies of JCV infected oligodendrocytes and teh cytoplasm of bizarre astrocytes. |
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