Study of Heterozygous Mice
In humans, it is generally known that unless a patient has both recessive CSTB genes (are homozygous recessive), they will not express ULD symptoms. A recent study has attempted to characterize the effects, if any, seen in mice that carry only one recessive CSTB gene (are heterozygous). The researchers analyzed normal and heterozygous mice by having them perform various tasks. The study found that heterozygous mice performed similar to normal mice when the task was started, but as the task continued or became more complex they were more likely to fail. While the results for the heterozygous mice were not remarkably different from the normal mice, they do indicate that carrying just one recessive CSTB gene may have adverse effects, at least in mice. Analysis of EEG as ULD Progresses
Currently, electroencephalography (EEG) is not very effective as a diagnostic tool for Unverricht–Lundborg disease. This study instead looks to characterize the change in EEG of ULD patients as the disease progresses. The researchers studied twenty-five patients with ULD and monitored their EEG over time. The results show that certain brain waves that are present at the beginning of ULD progression and are also present in unaffected individuals, including spontaneous generalized spike or polyspike wave discharges and photoparoxysmal response, tend to decrease after 10 to 15 years. References
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A viral disease (or viral infection) occurs when an organisms body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. Structural Characteristics
Basic structural characteristics, such as genome type, virion shape and replication site, generally share the same features among virus species within the same family. Double-stranded DNA families: three are non-enveloped (Adenoviridae, Papillomaviridae and Polyomaviridae) and two are enveloped (Herpesviridae and Poxviridae). All of the non-enveloped families have icosahedral capsids. Partly double-stranded DNA viruses: Hepadnaviridae. These viruses are enveloped. One family of single-stranded DNA viruses infects humans: Parvoviridae. These viruses are non-enveloped. Positive single-stranded RNA families: three non-enveloped (Astroviridae, Caliciviridae and Picornaviridae) and four enveloped (Coronaviridae, Flaviviridae, Retroviridae and Togaviridae). All the non-enveloped families have icosahedral nucleocapsids. Negative single-stranded RNA families: Arenaviridae, Bunyaviridae, Filoviridae, Orthomyxoviridae, ParamyxoviridaeParamyxoviridae and Rhabdoviridae. All are enveloped with helical nucleocapsids. Double-stranded RNA genome: Reoviridae. The Hepatitis D virus has not yet been assigned to a family, but is clearly distinct from the other families infecting humans. Viruses known to infect humans that have not been associated with disease: the family Anelloviridae and the genus Dependovirus. Both of these taxa are non-enveloped single-stranded DNA viruses. Pragmatic Rules
Human-infecting virus families offer rules that may assist physicians and medical microbiologists/virologists.As a general rule, DNA viruses replicate within the cell nucleus while RNA viruses replicate within the cytoplasm. Exceptions are known to this rule: poxviruses replicate within the cytoplasm and orthomyxoviruses and hepatitis D virus (RNA viruses) replicate within the nucleus.