Does the dose of iodine-131 influence the incidence of Graves\u27 ophthalmopathy?

BACKGROUND: Radioactive iodine-131 (RAI) is an established treatment for patients with Graves\u27 hyperthyroidism. RAI is reported to be associated with a 20-30% incidence of development or exacerbation of Graves\u27 ophthalmopathy (GO). This study compares the progression of GO in patients who had evidence or no evidence of GO before RAI therapy. PATIENTS AND METHODS: Forty-eight patients were studied. One group had no evidence whereas the other group had evidence of GO before RAI treatment. All underwent RAI therapy. Group A (27 patients, 18 women, nine men, age: 19-68 with a mean of 49 years) had pre-existing exophthalmos. Group B consisted of 21 patients (13 women, eight men, age: 30-63 with a mean of 43 years) developed exophthalmos after treatment. All patients underwent RAI therapy and followed by ophthalmologists. RESULTS: The average administered dose in group A was 24.3 mCi (range: 10-36.2 mCi) compared with group B: 25.4 mCi (range: 13-35.9 mCi), P=0.60. Ten (37%) of the 27 patients in group A experienced worsening of symptoms post-treatment. There was no significant difference between the administered dose of RAI in patients with worsening symptoms, 25.1 mCi versus patients with stable symptoms, 24.5 mCi (P=0.82). However, group A developed GO symptoms earlier than group B (4.5 vs. 9.5 months), P=0.02. CONCLUSION: RAI is known to exacerbate ophthalmopathy. Our study showed it was not dose-dependent. Patients without a previous history of GO were observed to have a significantly delayed period for the development of symptoms

HI 6 human serum albumin nanoparticles-Development and transport over an in vitro blood-brain barrier model

The standard treatment of intoxication with organophosphorus (OP) compounds includes the administration of oximes acting as acetylcholinesterase (AChE) reactivating antidotes. However, the blood-brain barrier (BBB) restricts the rapid transport of these drugs from the blood into the brain in therapeutically relevant concentrations. Since human serum albumin (HSA) nanoparticles enable the delivery of a variety of drugs across the BBB into the brain, HI 6 dimethanesulfonate and HI 6 dichloride monohydrate were bound to these nanoparticles in the present study. The resulting sorption isotherms showed a better fit to Freundlich's empirical adsorption isotherm than to Langmuir's adsorption isotherm. At the pH of 8.3 maximum drug binding capacities of 344.8g and 322.6g per mg of nanoparticles were calculated for HI 6 dimethanesulfonate and HI 6 dichloride monohydrate, respectively. These calculated values are higher than the adsorption capacity of 93.5g/mg for obidoxime onto HSA nanoparticles determined in a previous study. In vitro testing of the nanoparticulate oxime formulations in primary porcine brain capillary endothelial cells (pBCEC) demonstrated an up to two times higher reactivation of OP-inhibited AChE than the free oximes. These findings show that nanoparticles made of HSA may enable a sufficient antidote OP-poisoning therapy with HI 6 derivatives even within the central nervous system (CNS)