DNA

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DNA

n. scientifically, deoxyribonucleic acid, a chromonal double chain (the famous "double helix") in the nucleus of each living cell the combination of which determines each individual's hereditary characteristics. In law, the importance is the discovery that each person's DNA is different and is found in each living cell, so a hair, blood, skin or any part of the body can be used to identify and distinguish an individual from all other people. DNA testing can result in proof of one's involvement or lack of involvement in a crime scene. While recent DNA tests have proved a convicted killer on death row did not commit a crime and resulted in his release, current debate concerns whether DNA evidence is scientifically certain enough to be admitted in trials. The trend is strongly in favor of admission.

DNA

abbreviation for deoxyribonucleic acid, a chemical which is found in virtually every cell in the body and which carries genetic information. Except for identical twins, each person's DNA is unique. DNA profiling doesn't allow the examination of every single difference between people's DNA so the concentration will be on those aspects which are most likely to yield a difference. DNA can be extracted from any cells that contain a structure called the nucleus, for example, blood, semen, saliva or hair.

Mitochondrial DNA is inherited only from a person's mother. Brothers and sisters have the same mitochondrial DNA type as their mother. This feature of mitochondrial DNA can be used for body identification. The γ-chromosome is present only in men and is largely unchanged as it passes through the male line of a family. The usefulness of the technique in criminal matters is vastly enhanced by the extent to which it is possible to compare a sample with other individuals. To this end there is a National DNA Database maintained by the ASSOCIATION OF CHIEF POLICE OFFICERS and managed by the FORENSIC SCIENCE SERVICE. Techniques vary. There is a UK offence of DNA theft. It is also of assistance in paternity matters.

References in periodicals archive ?
cccDNA within infected hepatocytes could be degraded.
Protzer, "Response to comment on "specific and nonhepatotoxic degradation of nuclear hepatitis B virus cccDNA"," Science, vol.
Because the quantification of HBV DNA included single- and double-stranded DNA, it was important to explore the relationship between HBV cccDNA in liver tissues and disease progression.
There is a possibility that more effective drugs or combination therapies, which can reduce intrahepatic cccDNA effectively, will be able to shorten the therapy period in the future.
HBsAg level may reflect the transcriptional activity of cccDNA as well as integrated HBV DNA mRNA production and translation to HBsAg (truncated) rather than the absolute amount of cccDNA.
A decline in serum HBV DNA reflects a reduction in viral replication while a decline in serum HBsAg represents a reduction in the translation of mRNAs produced from transcriptionally-active cccDNA or integrated sequences.[sup][30] The viral response during treatment alone may not represent a reliable indicator of SVR to antiviral therapy, and the kinetics of HBV DNA and HBsAg level are dissociated in NA-treated patients and relapsers to PEG-IFN.
Ducroux et al., "HBx relieves chromatin-mediated transcriptional repression of hepatitis B viral cccDNA involving SETDB1 histone methyltransferase," Journal of Hepatology, vol.
Nassal, "HBV cccDNA: viral persistence reservoir and key obstacle for a cure of chronic hepatitis B," Gut, vol.
When HBV infects a host cell, the partial double-stranded DNA is repaired generating the covalently closed circular DNA (cccDNA), and then, this DNA is transcribed into different mRNAs; one is the pregenomic RNA (pgRNA).
That stops productive infection after viral entry by blocking steps needed to form covalently closed circular DNA (cccDNA) and accumulation of HBV core in the nuclei.
Viral eradication is not currently a goal of therapy, as none of the available therapeutic agents clear the highly stable covalently closed circular DNA (cccDNA) from hepatocytes.
In addition, the latest report showed that human Bocaviruscould integrate in the host genome by persisting in some infected tissues in the form of cccDNA and then contribute to the development of some lung and colorectal tumors [24].