Chronic Hepatitis B Infection: Principles of Therapy

Abstract

Chronic hepatitis B is a global health concern in many resource-limited settings due to perinatal or pediatric hepatitis B virus transmission. In the United States, pediatric infection has been virtually eliminated due to maternal screening during pregnancy and the availability of an effective vaccine. However, young adults remain an at-risk group for hepatitis B virus infection due to sexual transmission and injection drug use. The frequency of progression from acute hepatitis B virus infection to chronic hepatitis B infection depends on multiple factors, including host immune function and age at time of hepatitis B virus infection. Fortunately, there are 7 currently approved therapies for chronic hepatitis B infection, and several emerging therapies that show promise. Despite the availability of these agents, many clinical questions still surround chronic hepatitis B therapy including when to start therapy, which agent is ideal for first and second line therapy, the appropriate duration of therapy, and the role of combination antiviral therapy. This review focuses on agents available for chronic hepatitis B management, including pharmacology, safety and efficacy data, monitoring parameters, and the role for each in chronic hepatitis B therapy in adult patients.

Simulations of micrometeoroid interactions with the Earth atmosphere

“…Since melting is only one of the processes included in the energy balance (8), we adopt a form of P spall that limits its value to 0.625 (the two different expressions make P spall a continuous function of T µMET , to avoid problems in the numerical integration). The assumed value for the µMET melting temperature is T melt = 1623 K. This is similar to values adopted in previous studies (Bonny & Balageas 1990;Love & Brownlee 1991;Flynn 1992;Scarsi 2004) and is the melting point of silicates that are the dominant phases in µMETs. The rate of mass loss caused by melting is thus given by…”