Reduction of covalently closed circular DNA with long-term nucleos(t)ide analogue treatment in chronic hepatitis B.

BACKGROUND AND AIMS: Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), a mini-chromosome essential for HBV replication, is supposed to be resistant to nucleos(t)ide analogue treatment. We investigated the effect of long-term nucleos(t)ide analogue treatment on cccDNA. METHODS: Among 129 patients who had been enrolled in previous international nucleos(t)ide analogue clinical trials and had liver biopsies at baseline and one year after treatment, we recruited 43 patients on long-term continuous treatment for 72 to 145months for a third liver biopsy. Serum HBV DNA, hepatitis B surface antigen (HBsAg) levels, total intrahepatic HBV DNA (ihHBV DNA), cccDNA, HBV pregenomic RNA (pgRNA) as well as histologic changes were examined. RESULTS: At the time of the third biopsy, serum HBV DNA levels were undetectable in all but one patient. The median levels of HBsAg, ihHBV DNA, and cccDNA were 2.88logIU/ml, 0.03copies/cell, and 0.01copies/cell, respectively. Compared to baseline levels, there was reduction of HBsAg levels by 0.54log (71.46%), ihHBV DNA levels by 2.81log (99.84%), and cccDNA levels by 2.94log (99.89%), with 49% having cccDNA levels below the detection limit. One patient had undetectable HBsAg. The median pgRNA level, measured only in the third biopsy, was 0.021copies/cell, with 40% of patients having undetectable pgRNA. CONCLUSIONS: Long-term nucleos(t)ide analogue treatment induced marked depletion of cccDNA in the majority of patients while serum HBsAg levels, though reduced, were detectable in all but one patient. Whether cccDNA depletion is sustained and associated with better patient outcome requires further study. LAY SUMMARY: It is generally presumed that a form of hepatitis B virus DNA, called covalently closed circular DNA (cccDNA), which hides inside the nuclei of liver cells of patients with chronic hepatitis B, cannot be reduced by antiviral treatment. The present study showed that with prolonged treatment (median period 126months), cccDNA can be markedly reduced, with 49% of liver biopsies having undetectable cccDNA. This suggests that viral replication capacity would be very low after prolonged antiviral treatment.

Three-dimensional stereotactic atlas of the adult human skull correlated with the brain, cranial nerves, and intracranial vasculature.

BACKGROUND: Although the adult human skull is a complex and multifunctional structure, its 3D, complete, realistic, and stereotactic atlas has not yet been created. This work addresses the construction of a 3D interactive atlas of the adult human skull spatially correlated with the brain, cranial nerves, and intracranial vasculature. NEW METHOD: The process of atlas construction included computed tomography (CT) high-resolution scan acquisition, skull extraction, skull parcellation, 3D disarticulated bone surface modeling, 3D model simplification, brain-skull registration, 3D surface editing, 3D surface naming and color-coding, integration of the CT-derived 3D bony models with the existing brain atlas, and validation. RESULTS: The virtual skull model created is complete with all 29 bones, including the auditory ossicles (being among the smallest bones). It contains all typical bony features and landmarks. COMPARISON WITH EXISTING METHOD(S): The created skull model is superior to the existing skull models in terms of completeness, realism, and integration with the brain along with blood vessels and cranial nerves. CONCLUSIONS: This skull atlas is valuable for medical students and residents to easily get familiarized with the skull and surrounding anatomy with a few clicks. The atlas is also useful for educators to prepare teaching materials. It may potentially serve as a reference aid in the reading and operating rooms.

Pharmacokinetics of LB80331 and LB80317 following oral administration of LB80380, a new antiviral agent for chronic hepatitis B (CHB), in healthy adult subjects, CHB patients, and mice.

LB80380, a dipivoxil ester prodrug of LB80331 (metabolite, LB80317), is a novel antiviral agent for chronic hepatitis B (CHB). The pharmacokinetics of LB80331/LB80317 were evaluated in two clinical studies and a study with mice. The clinical studies were dose-escalating pharmacokinetic studies with six healthy subjects per single-dose group and six CHB patients per repeated-dose group. The mouse study was designed to measure the amounts of the phosphorylated portions of LB80331 and LB80317 in the liver. In healthy subjects receiving a single dose of LB80380, the plasma level of LB80331 increased as the dose increased. Although a high-fat diet delayed the time to the maximum concentration in plasma (T(max)) of LB80331, the area under the concentration-time curve from time zero to infinity was similar between the subjects in the fasted group and those in the group who consumed a high-fat diet. In CHB patients, the mean T(max) of LB80331 was 1.0 to 2.0 h postdosing at steady state. The steady-state plasma concentration of LB80331 declined in a monoexponential manner, and the apparent elimination half-life was 2.5 to 3.3 h. The steady-state plasma concentration of LB80317 was maximum at 3 to 8 h postdoing and declined in a monoexponential manner; the apparent elimination half-life was 45 to 62 h at the 30- to 240-mg doses, while LB80317 was measurable in plasma only at higher doses of 120 and 240 mg after the administration of the first dose of LB80380. Forty percent of the amount of LB80331/LB80317 in the mouse liver was detected as the phosphorylated form. In conclusion, LB80380 is rapidly absorbed and converted to LB80331. LB80317 has a long half-life at steady-state, supporting the use of a once-daily dosing regimen. The ingestion of a high-fat diet delays the rate of absorption of LB80380 without affecting the extent of absorption.

Long-term lamivudine therapy reduces the risk of long-term complications of chronic hepatitis B infection even in patients without advanced disease.

BACKGROUND: Long-term effects of lamivudine treatment on chronic hepatitis B patients without advanced disease remain unknown. Our aim was to investigate the effects of long-term lamivudine treatment and lamivudine-resistant virus (YMDD) on the development of cirrhosis and hepatocellular carcinoma (HCC) in asymptomatic patients without advanced disease. METHODS: One hundred and forty-two hepatitis B e antigen (HBeAg)-positive patients (median age: 33.9 years) on long-term lamivudine (median treatment duration: 89.9 months) and 124 HBeAg-positive controls (median age: 33.4 years) were prospectively followed up. Patients were monitored for the development of cirrhosis and HCC, liver biochemistry, hepatitis B virus (HBV) DNA levels, HBeAg seroconversion and hepatitis flares. YMDD mutations (YMDD-MT) were determined annually. RESULTS: Lamivudine-treated patients had a significantly lower cumulative rate of development of cirrhosis and/or HCC compared with controls (P = 0.005). YMDD-MT occurred in 76.3% of patients after 8 years of lamivudine treatment. When compared with controls and patients with YMDD-MT, patients without YMDD-MT had the greatest reduction of HBV DNA and bilirubin levels, slowest decline of albumin level, highest rate of HBeAg seroconversion and lowest risk of hepatitis flare. Patients with YMDD-MT still had a lower risk for developing cirrhosis and/or HCC (P = 0.024) and a greater HBV DNA reduction (P = 0.001) in comparison with controls. Patients with YMDD-MT and controls had a similar chance of hepatitis flares and hepatic decompensation. CONCLUSIONS: Long-term lamivudine treatment was associated with a reduced chance of developing cirrhosis and HCC in patients without advanced disease. Although YMDD-MT reduced the benefits from lamivudine therapy, the outcome of these patients was still better than untreated patients.

One-year entecavir or lamivudine therapy results in reduction of hepatitis B virus intrahepatic covalently closed circular DNA levels.

Entecavir and lamivudine are potent nucleoside analogues that can suppress hepatitis B virus (HBV) replication. However, the effects of these two antiviral agents on intrahepatic total HBV DNA and covalently closed circular DNA (cccDNA) are not known. In this study, we aimed to assess the effect of 48 weeks of entecavir/lamivudine therapy on intrahepatic total HBV DNA and cccDNA levels. Forty chronic hepatitis B patients, participating in two Phase III entecavir trials at our centre, were randomized to receive 48 weeks of either 0.5 mg once daily of entecavir (n = 21) or 100 mg once daily of lamivudine (n = 19). Their serological, virological and biochemical responses, as well as intrahepatic HBV DNA levels were monitored. There was no significant difference between entecavir and lamivudine therapy in terms of post-treatment serological, virological and biochemical responses. Both nucleoside analogues reduced serum viral load, intrahepatic total HBV DNA, and cccDNA by about 4.8 logs, 2 logs, and 1 log respectively. An increase in the proportion of intrahepatic HBV DNA in the form of cccDNA was seen after 48 weeks of therapy. In conclusion, both entecavir and lamivudine can successfully reduce intrahepatic HBV DNA and cccDNA. CccDNA becomes the dominant form of HBV DNA during viral suppression and is possibly responsible for viral rebound after short-term antiviral therapy.

A randomized placebo-controlled, dose-finding study of oral LB80380 in HBeAg-positive patients with chronic hepatitis B.

BACKGROUND: LB80380 is potent antiviral agent against hepatitis B virus (HBV) in vitro and in the woodchuck model. It has an excellent preclinical safety profile including lower potential for renal toxicity than adefovir. It is effective against both wild-type and YMDD mutant HBV. LB80380 is converted to its parent drug, LB80331, after oral absorption, and further metabolized to its active form, LB80317. AIMS/METHODS: This randomized placebo-controlled Phase I/II clinical study of LB80380 was conducted to assess the safety, antiviral activity and pharmacokinetics of its parent drug LB80331 and its active form LB80317 in 29 Asian adults with chronic hepatitis B positive for hepatitis B e antigen in four escalating dose groups (30, 60, 120 and 240 mg once per day) for 4 weeks with a 12-week follow-up period. RESULTS: The mean maximum HBV DNA reduction was 3.05, 4.20, 3.67 and 3.68 log10 copies/ml for 30, 60, 120 and 240 mg per day, respectively. Viral dynamic analysis suggested a high degree of inhibition of HBV replication at doses of 60 mg or higher per day. LB80380 was well tolerated at all dose groups, and no dose-related clinical or laboratory adverse event was reported. CONCLUSION: LB80380 is shown to be a potent and safe antiviral agent for HBV. Marked HBV DNA suppression was observed in all dose groups. The HBV DNA suppression was approximately constant at doses of 60 mg and higher over the 28-day dosing period. The dose response of LB80380 will be evaluated further in large clinical studies.

Characterization of Actinobacillus actinomycetemcomitans isolated from young Chinese aggressive periodontitis patients.

OBJECTIVE: This study characterized Actinobacillus actinomycetemcomitans isolates from young Chinese aggressive periodontitis patients. METHODS: Subgingival plaque samples (two/subject) were collected from diseased subjects < 25 years old (n = 9, mean age 21.1 +/- 1.6 years) and age-matched periodontitis-free controls (n = 47, mean age 22.0 +/- 1.1 years). Selective and anaerobic culture were used. The serotype, leukotoxin gene (ltx) operon promoter and the cytolethal distending toxin (cdt) genes complex of the A. actinomycetemcomitans isolates were investigated. Effects of the isolates on non-keratinizing periodontal ligament epithelial cells monolayer were studied. RESULTS: Diseased subjects had significantly higher full-mouth bleeding score (p = 0.002) and total viable counts from plaque samples (7.2 x 10(6) vs. 2.1 x 10(5) CFU/paperpoint, p < 0.005). A. actinomycetemcomitans was isolated from 67%/56% or 6%/4% of diseased or controls subject/sites, respectively (p < 0.001). The proportion of A. actinomycetemcomitans isolatable from aggressive periodontitis or periodontitis-free associated subgingival plaque was low (0.7% vs. 0.1%, p < 0.02). The serotype of the isolates was characterized. All isolates possessed 652-like ltx gene promoter and all but one serotype c isolate from a diseased patient had intact cdtABC genes. That particular strain appeared to confer the least cellular damages on periodontal ligament epithelial monolayer compared to others. CONCLUSION: This preliminary study confirmed the notion of increased prevalence and quantity of A. actinomycetemcomitans associated with aggressive periodontitis in young patients. The overall ltx promoter and cdt characteristics of the A. actinomycetemcomitans isolates, however, were similar among the diseased and control groups. A strain lacking the cdtABC gene appeared to be less damaging to a periodontal ligament epithelial cell model. Further studies therefore are warranted to clarify the pathogenic role and potentials of A. actinomycetemcomitans in aggressive periodontitis.