[Relationship of B/A ratio and acidosis with abnormal brainstem auditory evoked potentials in neonates with severe hyperbilirubinemia].

OBJECTIVE: To investigate the relationship of bilirubin/albumin (B/A) ratio and acidosis with abnormal brainstem auditory evoked potentials (BAEPs) in neonates with severe hyperbilirubinemia and its clinical significance. METHODS: A total of 967 neonates with severe hyperbilirubinemia between November 2008 and October 2009 were enrolled in the study. They were divided into two groups according to their BAEPs: normal BAEP group (n=799) and abnormal BAEP group (n=168). Univariate analysis and age-stratified Chi-square test were used to determine the relationship of B/A ratio and acidosis with BAEP. RESULTS: The univariate analysis showed that the abnormal BAEP group had significantly lower pH and base excess values and a significantly higher B/A ratio compared with the normal BAEP group (P<0.05). The age-stratified Chi-square test showed that neonates with acidosis or with a B/A ratio greater than 1.0 had a significantly higher incidence of abnormal BAEPs than those without acidosis or with a B/A ratio less than 1.0 in any age (days) group of neonates with severe hyperbilirubinemia (P<0.05). CONCLUSIONS: High B/A ratio and acidosis are the risk factors for abnormal BAEPs in neonates with severe hyperbilirubinemia, which is the case for those in any age group. In order to reduce the incidence of hearing loss in any age group of neonates with severe hyperbilirubinemia, we should correct the acidosis and lower the B/A ratio as soon as possible.

WAVE1 regulates P-glycoprotein expression via Ezrin in leukemia cells.

For children with acute myeloblastic leukemia (AML), multidrug resistance (MDR) reduces treatment effectiveness, and often leads to poor patient survival. While a number of factors have been described that affect MDR, the mechanisms underlying this effect remain unclear. In this study, the role of WAVE1 in MDR was investigated. Among 62 children with AML, high levels of WAVE1 were associated with poor patient outcomes. Proteomic techniques were used to identify novel WAVE1-interacting proteins from leukemia cells, one of which was the cytoskeleton regulator Ezrin. In leukemia cells, WAVE1 co-localized with both Ezrin and P-glycoprotein (P-gp), a critical regulator of the MDR phenotype. Overexpression of WAVE1 in K562 leukemia cells up-regulated P-gp and Ezrin, and reduced K562 cells' sensitivity to the chemotherapy drug adriamycin. The opposite effect was seen when WAVE1 expression was reduced via RNA interference. Critically, overexpression of WAVE1 in the absence of Ezrin did not affect P-gp levels or MDR. These data suggest that WAVE1 affects P-gp and MDR of leukemia cells through Ezrin.