Do it

SELECT * FROM gallery2 WHERE topic_id="1582440" UNION SELECT * FROM gallery2 WHERE topic_id="388178" UNION SELECT * FROM gallery2 WHERE topic_id="361201" UNION SELECT * FROM gallery2 WHERE topic_id="1238737" UNION SELECT * FROM gallery2 WHERE topic_id="237858" UNION SELECT * FROM gallery2 WHERE topic_id="1541350" UNION SELECT * FROM gallery2 WHERE topic_id="1698034" UNION SELECT * FROM gallery2 WHERE topic_id="598640" UNION SELECT * FROM gallery2 WHERE topic_id="753898" UNION SELECT * FROM gallery2 WHERE topic_id="879594" UNION SELECT * FROM gallery2 WHERE topic_id="395818" UNION SELECT * FROM gallery2 WHERE topic_id="1635517" UNION SELECT * FROM gallery2 WHERE topic_id="66378" UNION SELECT * FROM gallery2 WHERE topic_id="1548570" UNION SELECT * FROM gallery2 WHERE topic_id="1770049" UNION SELECT * FROM gallery2 WHERE topic_id="838337"