In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: The incidence and predictors of spontaneous hepatitis B surface-antigen (HBsAg) seroclearance in patients with chronic hepatitis B virus (HBV) were evaluated.', 'A total of 1427 patients with chronic HBV infection, who were followed between 1994 and 2013, were investigated in this retrospective study. All data were extracted from patient files.', 'Spontaneous HBsAg seroclearance occurred in 84 patients during 8798 person-years of follow-up. The patients were categorized into 3 groups at follow-up based on HBV DNA features as continuously <100 copies/mL (Group A), 0-10,000 copies/mL (Group B), and 0 to >10,000 copies/mL (Group C). Alanine aminotransferase features in the 2 groups were categorized as continuously normal (<40 U/L) and 0 to >40 U/L. Spontaneous HBsAg seroclearance was seen primarily in patients with Group A HBV DNA features, and continuously low HBV DNA values were the main predictor of HBsAg seroclearance (P < 0.001).\Question: Is a persistently low HBV DNA level a predictor of spontaneous HBsAg clearance in patients with chronic hepatitis B?
These results suggest that a continuously low viral load is the most important factor affecting spontaneous HBsAg seroclearance.

Context: Matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9) play a key role in tissue remodelling after processes such as joint destruction in rheumatoid arthritis. Their expression may reflect the disease activity and they could therefore represent a useful marker to assess the efficacy of therapy. In this study MMP-2 and MMP-9 serum were evaluated in patients with chronic arthritis during therapy with the anti-TNFalpha mAb, infliximab.', 'Fifty patients with chronic arthritis, 26 with rheumatoid arthritis and 24 with undifferentiated chronic arthritis, were recruited and treated with infliximab (3 mg/kg). Serum concentrations of MMP-2 and MMP-9 were serially measured by gelatine zymography at baseline and after two and fourteen weeks of infliximab therapy. DAS-28 and ACR response criteria were applied to assess disease activity and clinical improvement. Twenty-four healthy donors were included in the study as controls.', 'Although therapy with infliximab induced a statistically significant reduction of the DAS-28 score and improvement of the ACR clinical response, MMP-2 and MMP-9 serum concentrations were not modulated during therapy with infliximab.\Question: Does infliximab therapy modify MMP-2 and MMP-9 serum concentrations in chronic arthritis?
Our study provides further evidence that blocking TNFalpha by infliximab is a powerful tool in the management of chronic arthritis. Nevertheless, infliximab does not seem to be able to modify the serum expression of MMP-2 and MMP-9, probably because modification of these enzymes is restricted to the site of joint inflammation and serum detection can not truly mirror the local situation. Additional soluble factors correlating with joint damage should be investigated as possible markers for monitoring anti-TNFalpha therapy.

Context: Polo-like kinase 1 (PLK1) controls the main cell-cycle checkpoints, suggesting utility of its inhibition for cancer treatment, including of highly proliferative pediatric cancer. This preclinical study explored the selective PLK1 inhibitor volasertib (BI 6727) alone and combined with chemotherapy in pediatric malignancies.', 'Inhibition of proliferation was explored in vitro using dimethylthiazol carboxymethoxyphenyl sulfophenyl tetrazolium (MTS) assay. Mice bearing human xenografts were treated with weekly intravenous injections of volasertib.', 'Volasertib inhibited proliferation in all 40 cell lines tested, with a mean half-maximal growth inhibitory concentration of 313 nmol/l (range: 4-5000 nmol/l). Volasertib was highly active against RMS-1 alveolar rhabdomyosarcoma xenografts, resulting in 100% tumor regression. Activity was associated with complete and prolonged G2/M arrest and subsequent apoptotic cell death. Volasertib showed synergistic activity with vincristine but antagonistic effects with etoposide.\Question: Does polo-like Kinase Inhibitor Volasertib exhibit Antitumor Activity and Synergy with Vincristine in Pediatric Malignancies?

These findings support the further exploration of volasertib for pediatric malignancies, particularly alveolar rhabdomyosarcoma, and its combination with mitotic spindle poison.