Who is Nikolai Stephanych from Stories of Anton Chekov and what is their importance?

Nikolai Stephanych's name is very popular and respected. He is a famous professor of medicine and a councillor. Stephanych is very old, with false teeth and wrinkled face. Stephanych describes his failing memory and his growing propensity toward insomnia. Even though he has aged and becoming decrepit, he is very disappointed that his wife aged as well. He looks at his fat, ungainly wife and tries to find in her the slender beauty he married. She only worries about poverty and bargains.