Dr. Teepu Siddique, a professor of neurology at Northwestern’s Feinberg School of Medicine, is pictured in his lab in Chicago on Friday, Aug. 19, 2011. Siddique has discovered a possible cause for ALS. (Keri Wiginton/ Chicago Tribune) B581489339Z.1 ….OUTSIDE TRIBUNE CO.- NO MAGS, NO SALES, NO INTERNET, NO TV, NEW YORK TIMES OUT, CHICAGO OUT, NO DIGITAL MANIPULATION…