Dave Coulier is responding to fans who have pointed out his changing appearance following a battle with both tongue cancer and lymphoma.  In a video shared to the “Full House” star’s Instagram on Thursday, the 66-year-old actor explained how treatments for the cancer have impacted him.  “Hi everyone, it’s me Dave, and I haven’t posted in quite a while and  the last time I did some of you said that I look differently, and I sound differently, and I do,” he began the video. “And what you’re seeing is the side effects of extensive radiation that I went through for carcinoma in my throat.” He continued: “I haven’t been able to eat solid food in months. So I’ve lost 45 pounds, that’s what you’re seeing. And it’s affected my ability to speak, some of you have said that I speak differently.…