Isolation of riboflavin carrier proteins from pregnant human and umbilical cord serum: Similarities with chicken egg riboflavin carrier protein

A riboflavin carrier protein has been purified from human pregnancy and umbilical cord sera by affinity chromatography and fast protein liquid chromatography. This protein has a similar molecular weight to the chicken egg riboflavin carrier protein and shares other physicochemical properties, such as pI and riboflavin binding characteristics, with the avian counterpart. A high degree of immunological cross-reactivity is observed between the human and avian riboflavin binding proteins indicating the extensive conservation of this protein throughout evolution.     

Correlation between riboflavin carrier protein induction and its mRNA activity in estrogen stimulated chicken liver and oviduct

Poly A enriched RNA from either liver or oviduct of estradiol-17β treated immature chicks supported [³H]-leucine incorporation into immunoprecipitable riboflavin carrier protein in a dose-dependent manner when translated in the rabbit reticulocyte lysate system. Primary translation product of riboflavin carrier protein had a molecular weight of 38,000 which on incubation with a stripped hepatic microsomal preparation was processed to a product with a size comparable to native riboflavin carrier protein. Poly A enriched RNA from both the liver and the oviduct of estrogen-treated birds stimulated [³H]-leucine incorporation into riboflavin carrier protein and this was 2–3 fold higher during secondary stimulationvis-a-vis primary stimulation with the steroid. Poly A enriched RNA from the liver of progesteronetreated birds during secondary stimulation did not support riboflavin carrier protein synthesis. In contrast, poly A enriched RNA from the oviduct of the birds treated with progesterone during secondary (but not primary) stimulation did exhibit riboflavin carrier protein-mRNA activity which was comparable to that stimulated by estradiol-17β     

Oral Acetazolamide after Boston Keratoprosthesis in Stevens Johnson Syndrome

ABSTRACT: BACKGROUND: Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare but severe and sometimes fatal condition associated with exposure to medications; sulfamethoxazole is among the most common causes. We sought to address the safety of acetazolamide, a chemically related compound, in patients with prior SJS/TEN and glaucoma. A retrospective case series is described of patients at the Massachusetts Eye and Ear Infirmary who underwent keratoprosthesis surgery for corneal blindness from SJS/TEN, and later required oral acetazolamide for elevated intraocular pressure. FINDINGS: Over the last 10 years, 17 patients with SJS/TEN received a Boston keratoprosthesis. Of these, 11 developed elevated intraocular pressure that required administration of oral acetazolamide. One of 11 developed a mild allergic reaction, but no patient experienced a recurrence of SJS/TEN or any severe adverse reaction. CONCLUSION: Although an increase in the rate of recurrent SJS/TEN due to oral acetazolamide would not necessarily be apparent after treating only 11 patients, in our series, acetazolamide administration was well tolerated without serious sequela.     

Early pregnancy termination in rats immunized with denatured chicken riboflavin carrier protein.

Immunoneutralization of the maternal riboflavin carrier protein in the pregnant rat with antibodies to chicken egg vitamin carrier has earlier been shown to terminate their pregnancies. In order to understand the nature of the epitopic conformations capable of eliciting antibodies bioneutralizing the endogenous riboflavin carrier protein in the pregnant rat, we compared pregnancy progression in the fertile rodents following active immunization with either the native, SDS-denatured, reduced-carboxymethylated or SDS-treated reduced carboxymethylated avian egg white riboflavin carrier protein. The data revealed that despite the total antibody titers being higher in the animals immunized with the native protein, the antibodies elicited against the denatured avian vitamin carrier exhibited relatively better potencies to bioneutralize the endogenous maternal protein as evidenced by higher rates of early fetal resorption.