The Mg insertion step in chlorophyll biosynthesis.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to J D Weinstein.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Two methods to deter the rapid intrathecal degradation of idoxuridine were investigated: (a) rapid drug perfusion through the ventricular system, and (b) modification of the molecule to its uronic acid derivative, 2'-deoxy-5-iodo-5'-uridinecarboxylic acid, to make it less susceptible to enzymatic digestion. Perfusion of idoxuridine through the ventricular system (ventriculocisternal) of dogs at 0.97 ml/min saturated the metabolic pathway so that the outflow solution yielded a single spot (Rf 0.76) on TLC indicative of the intact molecule. The 125I-labeled uronic acid was synthesized from the 125I-labeled parent compound, and the labeled compounds were compared after their individual intracisternal injection in dogs. Since there was no difference in the disappearance rates, the stability of the uronic acid was, in fact, no greater than that of the parent compound in vivo. Ventricular perfusion of idoxuridine, however, seems a suitable means for increasing the amount of active drug delivered to central nervous system tumors and viral infections.
Two cases of spinal arteriovenous malformation (AVM) in young patients are presented. Symptoms were compatible with the spinal form of multiple sclerosis in both cases. The lesions were not diagnosed on initial evaluation. Subsequently they were found by myelography and arteriography, the one eight months and the other nine years after the first symptoms. The contrasting clinical courses of the two patients suggest that: (a) the diagnosis of multiple sclerosis where symptoms and signs are restricted to the spinal cord should be made only after a thorough investigation which includes myelography, to rule out the presence of a surgically correctible lesion such as an AVM; (b) myelography should be carried out in both the supine and prone positions as an AVM may be completely missed by routine prone myelography views; (c) early surgery of the resectable AVM may prevent a progressive deterioration of neurological function, making early diagnosis particularly important.