MTV Networks Intl. will bow a local-language version of Nickelodeon in Poland on June 1 as it continues to ramp up its presence in Central and Eastern Europe.Nickelodeon Poland will carry U.S. content plus original local productions and acquisitions. It joins MTV Nets Intl.’s MTV, Viva, VH1 and Comedy Central, which was the first local Comedy Central service to launch outside the U.S. Elsewhere in the region, MTV Nets Intl. and Russia’s Prof-Media have appointed Alexey Efimov as general manager of MTV Russia, which Prof-Media operates under license. Based in Moscow, Efimov was general manager of Channel One Russia.