Paul Donahoe (Davison, Mich.) placed fourth at 50 kg/110 lbs. at the Junior World Freestyle Wrestling Championships in Istanbul, Turkey, Saturday, August 30.    The Junior World Championships feature the world's best wrestlers who are 17-20 years old.    Donahoe lost both of his bouts to fall short of winning a medal. In the semifinals, he was defeated by eventual champion Bahrami Farzan of Iran. In the bronze-medal match, he dropped a 6-4 decision to Maksim Petrov of Bulgaria.    Three weight classes were completed with medal matches on Saturday. At 74 kg/163 lbs, Don Reynolds (New Lenox, Ill./Overtime WC) placed seventh after being eliminated on Friday in the quarterfinals. At 60 kg/132 lbs., Nate Gallick (Tucson, Ariz./Cyclone WC) just missed earning a top 10 placement, taking 11th in his division. He was also eliminated on Friday.    Two U.S. wrestlers remain alive in the hunt for medals in their divisions: Andy Simmons (Williamston, Mich./Michigan WC) at 66 kg/145.5 lbs. and Kurt Backes (Neshanic Station, N.J./Cyclone WC) at 84 kg/185 lbs.    Simmons won all three of his pool matches by technical fall, crushing Salvis Pudovs of Latvia, 15-5, Scott MacGregor of New Zealand, 10-0 and Goran Atanosa of Macedonia, 10-0. He will face Abbas Rangbar of Iran in the quarterfinals.    Backes, who won two bouts on Friday, claimed his pool competition by pinning pin Navender Kumar of India for his third straight win. Backes will face Georgy Tibilov of Russia in the quarterfinals.    Three other U.S. wrestlers were eliminated from medal contention by losing matches in their pool competitions: Mike Silengo (Colorado Springs, Colo./Dave Schultz WC) at 55 kg/121 lbs., 96 Nathan Moore (Indianapolis, Ind./Purdue) at kg/211.5 lbs. and Cole Konrad (New London, Wis./Minnesota Storm) at 120 kg/264.5 lbs.    The U.S. athletes are being coached by Terry Steiner, who lives in Madison, Wis., along with Donny McPherson of Portland, Ore.    JUNIOR WORLD CHAMPIONSHIPS  At Istanbul, Turkey, August 30    Medal winners from the first three divisions    50 kg/110 lbs. - Gold - Bahrami Farzhan (Iran); Silver - Zhassulan Mukhtabekuly (Kazakhstan); Bronze - Maksim Petrov (Bulgaria)    60 kg/132 lbs. - Gold - Makhach Murtazaliev (Russia); Silver - Meiremzhan Baisebayev (Kazakhstan); Bronze - Gergoe Waller (Hungary)    74 kg/163 lbs. - Gold - Sergey Vitkovsiy (Russia); Silver - Misan Amini (Iran); Bronze - Gabor Hatos (Hungary)    U.S. Junior World Freestyle Team results    50 kg/110 lbs. - Paul Donahoe (Davison, Mich.), 4th - tech. Fall over Frank Osei Mensah (Canada), 10-0; dec. Evgeni Nikanorov (Israel), 9-8; lost dec. to Bahrami Farzan (Iran); lost dec. to Maksim Petrov (Bulgaria), 6-4    55 kg/121 lbs. - Mike Silengo (Colorado Springs, Colo./Dave Schultz WC) - lost dec. to Anil Kumar (India), 7-3; lost dec. to Malkhaz Kurdiani (Georgia), 8-6    60 kg/132 lbs. - Nate Gallick (Tucson, Ariz./Cyclone WC), dnp/11th - dec. Luis Ortiz (Puerto Rico), 8-2; tech. fall Bevilacqua Cianmarco (Italy), 10-0; lost dec. to Koba Kakaladze (Georgia), 4-0    66 kg/145.5 lbs. - Andy Simmons (Williamston, Mich./Michigan WC) - tech. fall over Salvis Pudovs (Latvia), 15-5; tech. fall Scott MacGregor (New Zealand), 10-0; tech. fall Goran Atanosa (Macedonia), 10-0    74 kg/163 lbs. - Don Reynolds (New Lenox, Ill./Overtime WC), 7th - dec. Sanjar Shodmanov (Uzbekistan), 8-0; dec. Tyler Marghetis (Canada), 6-1; lost dec. to Sergey Vitkovsky (Russia), 6-0    84 kg/185 lbs. - Kurt Backes (Neshanic Station, N.J./Cyclone WC) - won by inj. Dft. Over Imants Lagodskis (Latvia); tech. fall Jonathan Rioux (Canada), 11-1; pin Navender Kumar (India)    96 kg/211.5 lbs. - Nathan Moore (Indianapolis, Ind./Purdue) - lost dec. to Andre Podsevalnicov (Moldova) 7-6; lost dec. to Dragomir Stoychev (Bulgaria), 3-1; lost dec. to Yacheni Zabela (Belarus), 3-2    120 kg/264.5 lbs. - Cole Konrad (New London, Wis./Minnesota Storm) - dec. Petro Raychev (Ukraine), 5-2; lost dec. to Jamerlan Piliev (Russia), 5-0    Coaches: Troy Steiner (Madison, Wis.), Don McPherson (Portland, Ore.)