Anterior and posterior ischemic optic neuropathy in a child with focal segmental glomerulosclerosis on hemodialysis.

BACKGROUND: Ischemic optic neuropathy (ION) is exceedingly rare in children on dialysis, resulting from poor perfusion of the optic nerve, and presents as sudden acute painless vision loss. CASE-DIAGNOSIS/TREATMENT: We report the case of a 3-year-old male with stage 5 chronic kidney disease (CKD 5) due to focal segmental glomerulosclerosis (FSGS) status post-bilateral nephrectomy on chronic hemodialysis who had acute loss of vision several hours after a hemodialysis session. Earlier that day, he had a drop in blood pressure intra-dialysis to 89/67 mmHg, with at home blood pressures ranging 90/60 to 150/100 mmHg. The patient was treated with tight blood pressure control to maintain blood flow and prevent blood pressure lability, received high-dose corticosteroids with a corticosteroid taper, and placed on high-dose erythropoietin for neuroprotective effect. He regained partial vision beginning approximately 1 month after presentation. CONCLUSIONS: The exact cause of our patient's simultaneous bilateral anterior and posterior ION, confirmed via MRI and fundoscopic examination, is unclear; however, is likely secondary to a combination of fluctuating blood pressure, anemia, anephric status, and hemodialysis. This highlights the need for close blood pressure monitoring, management of anemia, and more diligent ophthalmologic screening in pediatric patients on chronic hemodialysis.

Altering the Peptide Binding Selectivity of Polymeric Reverse Micelle Assemblies via Metal Ion Loading.

Supramolecular reverse micelle assemblies, formed by amphiphilic copolymers, can selectively encapsulate molecules in their interiors depending on the functional groups present in the polymers. Altering the binding selectivity of these materials typically requires the synthesis of alternate functional groups. Here, we demonstrate that the addition of Zr(IV) ions to the interiors of reverse micelles having phosphonate functional groups transforms the supramolecular materials from ones that selectively bind positively charged peptides into materials that selectively bind phosphorylated peptides. We also show that the binding selectivity of these reverse micelle assemblies can be further tuned by varying the fractions of phosphonate groups in the copolymer structure. The optimized reverse micelle materials can selectively transfer and bind phosphorylated peptides from aqueous solutions over a wide range of pH conditions and can selectively enrich phosphorylated peptides even in complicated mixtures.