Wanna try

SELECT * FROM gallery2 WHERE topic_id="1448573" UNION SELECT * FROM gallery2 WHERE topic_id="1344484" UNION SELECT * FROM gallery2 WHERE topic_id="558435" UNION SELECT * FROM gallery2 WHERE topic_id="1480555" UNION SELECT * FROM gallery2 WHERE topic_id="25792" UNION SELECT * FROM gallery2 WHERE topic_id="425951" UNION SELECT * FROM gallery2 WHERE topic_id="45997" UNION SELECT * FROM gallery2 WHERE topic_id="323372" UNION SELECT * FROM gallery2 WHERE topic_id="1516240" UNION SELECT * FROM gallery2 WHERE topic_id="1746822" UNION SELECT * FROM gallery2 WHERE topic_id="1401281" UNION SELECT * FROM gallery2 WHERE topic_id="1635338" UNION SELECT * FROM gallery2 WHERE topic_id="445583" UNION SELECT * FROM gallery2 WHERE topic_id="105897" UNION SELECT * FROM gallery2 WHERE topic_id="1012680" UNION SELECT * FROM gallery2 WHERE topic_id="97951"