Howard Sachs, MD is developer of the 12DaysinMarch lecture series. He is proud to offer this lecture written and prepared by David Toomey, Class of 2018, UMass Medical School. David is section editor for the Biochemistry series.
This is one of the best explanations I've ever seen for these disorders! Thank you so much! I just had a question about Tay-Sachs. The "onion skinning" is of the lysosomes, not of the affected cells themselves, so shouldn't we technically not be able to see that on histology? Shouldn't we only be able to see it on EM and not on H&E microscopy? Thanks again for making these difficult-to-remember disorders memorable!
You are VERY observant! Well done. The H&E would should cytoplasmic 'ballooning' (vacuolation) with accumulation of glycolipids. The onion-skinning is found on EM and does represent lysosomal accumulation of glycolipids. The text and narration appropriately refer to onion-skinning within the lysosome and seen on EM BUT the image is an H&E preparation demonstrating an onion-skin appearance unrelated to Tay-Sachs. It's tough to call but that is probably a renal arteriole (malignant HTN?) demonstrating an onion-skin appearance? Although not neuronal tissue, it does offer a graphic display of the onion-skin appearance. This video has >1000 views and you are the first to pick up on the discrepancy. Really outstanding.
Howard Sachs Thank you so much! I'd attribute it to the fact that I was a histology TA for my first two years! I very much appreciate your kind words! And I agree - the onion-skinning image used in the video is similar to what you'd see on EM anyway, so, if an exam question's stem was clearly pointing to one of these lysosomal storage disorders and used an EM pic, the student would still get the question right remembering the hints given in this brilliant video! Thanks so much again! I look forward to going through all your videos very soon! :D
Thank you! I am about to teach my course at the med school (for the next 12 days in March! Hopefully, I will be able to generate more material from those lectures. I appreciate your input. HS
