Polioencephalitis Polioencephalitis Polioencephalitis is a viral infection of the brain, causing inflammation within the grey matter of the brain stem. The virus has an affinity for neuronal cell bodies and has been found to affect mostly the midbrain, pons, medulla and cerebellum of most infected patients. The infection can reach up through the thalamus and hypothalamus and possibly reach the cerebral hemispheres. The infection is caused by the poliomyelitis virus which is a single-stranded, positive sense RNA virus surrounded by a non-enveloped capsid. Humans are the only known natural hosts of this virus. The disease has been eliminated from the U.S.
Medulla (hair) The medulla's presence in human hair and its patterns differ both from person to person and from strand to strand on a single person's head. One hair may have an absent medulla while another from the same person may have a complete or fragmented medulla. For this reason, medulla patterns are not very useful as forensic evidence and are typically only used for determining the species of the subject. The medulla contains large amounts of mitochondrial (as opposed to nuclear) DNA. Mitochondrial DNA is passed from the mother to her offspring. As such, mtDNA may be of forensic value. Medulla