From kestrel91316 on Democratic Underground:
Wednesday, 3/21/07 5:46 PM
New Etiological Info on Pet Food Contamination Incident…
Toxicologists have tentatively ruled out ochratoxin, a fungal toxin that was initially suspected, though mycotoxins can be extraordinarily difficult to detect. They also have ruled out common chemical toxins like antifreeze and the types of solvents and cleaning agents used in the plant.
Interest seems to be centering now on the mysterious crystals being found in some of the victims’ urine samples, and in large quantities in kidney tissue of some deceased victims (postmortem findings). We do not know what these crystals are, and different types of crystals appear to be found in different patients (????). Some appear to be “sulfa” crystals. Some appear to be urate crystals. Still more appear to be oxalate crystals.
I am baffled. But then, I’m not a pathologist.
Wednesday, 3/21/07 6:27 PM
Post from a Veterinary Pathologist in Georgia:
A cat was presented to the University of Georgia Veterinary Teaching Hospital this morning with suspicion of food-related toxicosis. The urinalysis revealed crystals with the appearance of broken dinner plates with coarse striations. These crystals were not readily recognized by the newer medical technologists, residents, and faculty.
The appearance of the crystals was suggestive of sulfa crystals to me (images). The presence of sulfa crystals subsequently was verified by the lignin test. A positive test result produces a bright orange color (image). The patient’s sample is on the left and the positive control is on the right.
The lignin test is simple and inexpensive. It is performed with a piece of used newsprint, urine sediment, 25% HCl solution, and a positive control (sulfa capsule suspension in water). The test is performed as follows. Apply one drop of urine sediment to the newsprint. In a different area, apply one drop of the sulfa suspension(positive control). Then apply a drop of HCl to the urine sediment and a second drop to the newsprint. A third drop of HCl applied to another area of the newsprint will serve as a negative control. Test results are as follows: positive control = bright orange spot, negative control = no reaction, patient sample turns orange if sulfa crystals are present.
Dr. L—– (omitted so he doesn’t get swamped by pet owner phone calls)
Department of Pathology
University of Georgia