Radiation dosimetry of iodine-123 HEAT, an alpha-1 receptor imaging agent

Biologic distribution data in the rat were obtained for the alpha-1 adrenoceptor imaging agent (+/-) 2-[beta-(iodo-4-hydroxyphenyl)ethylaminomethyl]tetralone (HEAT) labeled with [125I]. The major excretory routes were through the liver (67%) and the kidney (33%). Internal radiation absorbed dose estimates to nine source organs, total body, the GI tract, gonads, and red bone marrow were calculated for the human using the physical decay data for [123I]. The critical organ was found to be the lower large intestine, receiving 1.1 rad per mCi of [123I]HEAT administered. The total-body dose was found to be 58 mrad per mCi.     

Melorheostosis: report of two cases affecting the jaw.

Melorheostosis is a rare sclerosing bone dysplasia that is characterized by a localized, diffuse thickening of the cortical bone. This condition usually affects the appendicular skeleton and associated soft tissue and rarely affects the craniofacial complex. The etiology of this condition is obscure. Diagnosis of melorheostosis relies on clinical, radiographic, and histological correlation. Only 8 cases of melorheostosis involving the craniofacial complex have been reported. We report 2 new cases of isolated melorheostosis involving the maxilla and mandible, together with differential diagnostic considerations. To our knowledge, involvement of the maxilla only has not been previously reported.     

The significance of reduced respiratory chain enzyme activities: clinical, biochemical and radiological associations.

BACKGROUND: Mitochondrial diseases are an important group of neurometabolic disorders in children with varied clinical presentations and diagnosis that can be difficult to confirm. AIM: To report the significance of reduced respiratory chain enzyme (RCE) activity in muscle biopsy samples from children. METHODS: Retrospective odds ratio was used to compare clinical and biochemical features, DNA studies, neuroimaging, and muscle biopsies in 18 children with and 48 without reduced RCE activity. RESULTS: Children with reduced RCE activity were significantly more likely to have consanguineous parents, to present with acute encephalopathy and lactic acidaemia and/or within the first year of life; to have an axonal neuropathy, CSF lactate >4 mmol/l; and/or to have signal change in the basal ganglia. There were positive associations with a maternal family history of possible mitochondrial cytopathy; a presentation with failure to thrive and lactic acidaemia, ragged red fibres, reduced fibroblast fatty acid oxidation and with an abnormal allopurinol loading test. There was no association with ophthalmic abnormalities, deafness, epilepsy or myopathy. CONCLUSION: The association of these clinical, biochemical and radiological features with reduced RCE activity suggests a possible causative link.