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covalently closed circular DNA

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covalently closed circular DNA (CCC-DNA)

completely double-stranded circular DNA with no breaks or NICKS. It often adopts a supercoiled conformation, (see SUPERCOILED DNA). Compare OPEN CIRCULAR DNA.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
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References in periodicals archive
(rc-DNA = relaxed circular DNA; HBV = hepatitis B virus; cccDNA = covalently closed circular DNA; pgRNA = pre-genomic RNA.)
(HBV = hepatitis B virus; rcDNA = relaxed circular DNA; HBsAg = hepatitis B surface antigen; cccDNA = covalently closed circular DNA; pgRNA = pre-genomic RNA.)
Current and future directions for the management of hepatitis B
(V.) panamensis is an active endonuclease able to degrade covalently closed circular DNA, demonstrating that these regions are not critical to the functioning of this enzyme.
Leishmania (Viannia) panamensis expresa una nucleasa molecular y bioquimicamente similar a la Endonucleasa G de eucariotas superiores
However, the challenge of antiviral therapy is to clear the HBV covalently closed circular DNA (cccDNA) pool.
The Effectiveness of Antiviral Treatments for Patients with HBeAg-Positive Chronic Hepatitis B: A Bayesian Network Analysis
In the mid-1970s, interferon-alpha began to be used to treat chronic hepatitis B (CHB), but the response rate to interferon-alpha treatment was low.[sup][2] After 1998, five nucleos(t)ide analogs (NAs)-lamivudine (LAM), adefovir dipivoxil (ADV), telbivudine (LdT), entecavir (ETV), and tenofovir disoproxil fumarate (TDF) were successively introduced, leading to a continuous virologic suppression and control of disease progression in CHB patients.[sup][3] NAs can inhibit viral replication by suppressing the process of reverse transcription, but they have a small effect in reducing intrahepatic covalently closed circular DNA (cccDNA).[sup][4] Therefore, long-term treatment might be beneficial to achieve the ultimate goal of clearance of hepatitis B surface antigen (HBsAg).[sup][5]
One-year entecavir or lamivudine therapy results in reduction of hepatitis B virus intrahepatic covalently closed circular DNA levels.
Dynamic Characteristics of Serum Hepatitis B Surface Antigen in Chinese Chronic Hepatitis B Patients Receiving 7 Years of Entecavir Therapy
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