The present invention provides to an improved hand truck having a tiltable platform for carrying heavy objects, which is safe to use and easily maneuverable, and requires the minimum amount of energy required for movement of heavy objects. The trailer further including a remote controlled power winch with an automatic shut off for stopping the power winch when a watercraft is fully loaded. The main-control element transmits the MIDI messages to the pre-processor. A method of activating B cells, and particularly of activating B cells in a mammal, such as a human, in need of such activation by administering LAIT protein is described.