WSJ --The Food and Drug Administration warned Abbott Laboratories’ diabetes unit about manufacturing violations involving the company’s blood-glucose monitoring systems. The July 2 letter stemmed from a March inspection of an Abbott Diabetes Care Inc. facility in Alameda, Calif., that makes the FreeStyle glucose-monitoring and the Navigator continuous-monitoring systems. The devices are used by people with diabetes to monitor their blood-glucose, or blood-sugar, levels. The letter was posted on FDA’s website Tuesday.