I was watching Newsradio on DVD and I just happened to notice that the doctor was played by the late John Ritter and when I saw him I was shocked that John Ritter guest starred on Newsradio and I didn't realize he appeared on the show until I saw it in the end credits. Was this one of John Ritter's last appearences before his ultimately death?
Bestie

No, he appeared on many more shows and movies since his "Newsradio" appearance.

"8 Simple Rules" was the show he was starring on when he died.