As if to make up for his lethargy in Mexico, Nikita came up with a bunch of new "words" while we were in NYC. Here is the current sampling:
Vocal:
mi(th): meaning unknown
bick-daba: meaning unknown, but seems to correlate with annoyance
kipke: shortened version for skripke, which means "violin" in Russian
[raspberry]: for car or other machine
Sign:
cat
banana/carrot (rubs flat hand on fist)
milk
lotion (strokes face with finger - his sign)
telephone (holds fist to face - his sign)
And two words I never thought I'd see him sign: eat, more. He's been much more behaved about food since his hospital trip.