Long-term entecavir therapy results in falls in serum hepatitis B surface antigen levels and seroclearance in nucleos(t)ide-naïve chronic hepatitis B patients

Entecavir (ETV) is reported to result in suppression of hepatitis B virus DNA (HBV DNA) replication with minimal drug resistance. However, information on the long-term effect of such therapy on serum hepatitis B surface antigen (HBsAg) level and elimination of HBsAg is not available. ETV therapy was started in 553 nucleos(t)ide-naïve patients with chronic hepatitis B infection (HBeAg positive: 45%) in our hospital. Serum HBsAg levels were measured serially by the Architect assay. The median baseline HBsAg was 2180 IU/mL (0.12-243 000 IU/mL), and median follow-up period was 3.0 years, with 529, 475, 355, 247 and 163 patients followed-up for 1, 2, 3, 4 and 5 years, respectively. At year 5, the mean log HBsAg decline from baseline was -0.48 log IU/mL, and the cumulative HBsAg clearance rate was 3.5%. Multivariate analysis identified HBV DNA level at baseline (<3.0 log copies IU/mL, odd ratio = 10.2; 95% confidence interval = 1.87-55.5, P = 0.007) and HBsAg level (<500 IU/mL, odd ratio = 29.4; 95% confidence interval = 2.80-333, P = 0.005) as independent predictors of HBsAg seroclearance. These results indicate that although serum HBsAg level declines gradually during ETV therapy, HBsAg seroclearance remains a rare event.

Numerical observation of the rescattering wave packet in laser-atom interactions

We present a full-quantum nonperturbative method to study the electron rescattering process in the intense laser-atom interactions. We separate the ionized wave function from the background by solving the time-integral equation. Imposing the incoming boundary condition on the wave function, we reproduce the motion of the rescattering wave packet predicted by the rescattering theory. Our calculated rescattering energies differ significantly from the semiclassical ones. The difference would be substantial for the evaluation of the rescattering induced dynamics such as the molecular dissociation.

[Sudden exacerbation in atypical syringomyelia with a unilateral superficial sensory disorders as the principal manifestation]

We report a 22 year-old woman with syringomyelia, who complained of a sudden abnormal sensation in the left neck and upper extremity after maintaining her neck in flexion for sometime. Neurologic examination revealed superficial hypesthesia on the left from C2 down, but normal motor function. The mode of onset in our patient was atypical. The clinical manifestations of syringomyelia are usually slowly progressive. On the basis of X-P film of the cervical spine and cranial MRI, a diagnosis of syringomyelia with Chiari malformation (type 1) was made. The syrinx cavity extended from C1 to L1. On the transaxial image of the cervical cord, the syrinx cavity was demonstrated in the posterior horn area ipsilateral to the sensory disturbance. The CSF flow-void sign was present in the syrinx cavity, probably reflecting pulsation of the syrinx fluid. An abnormally high signal intensity area adjacent to the syrinx cavity on T2-weighted sequences indicated damaged cord. We speculate that dynamic factors produced by neck flexion and fluid pulsation explain the sudden exacerbation in our patient.