Simple

SELECT * FROM gallery2 WHERE topic_id="528537" UNION SELECT * FROM gallery2 WHERE topic_id="1550269" UNION SELECT * FROM gallery2 WHERE topic_id="145484" UNION SELECT * FROM gallery2 WHERE topic_id="1827415" UNION SELECT * FROM gallery2 WHERE topic_id="24001" UNION SELECT * FROM gallery2 WHERE topic_id="817138" UNION SELECT * FROM gallery2 WHERE topic_id="574514" UNION SELECT * FROM gallery2 WHERE topic_id="158254" UNION SELECT * FROM gallery2 WHERE topic_id="1680849" UNION SELECT * FROM gallery2 WHERE topic_id="1420627" UNION SELECT * FROM gallery2 WHERE topic_id="347625" UNION SELECT * FROM gallery2 WHERE topic_id="1328178" UNION SELECT * FROM gallery2 WHERE topic_id="13348" UNION SELECT * FROM gallery2 WHERE topic_id="615214" UNION SELECT * FROM gallery2 WHERE topic_id="1827900" UNION SELECT * FROM gallery2 WHERE topic_id="1487361"