Treatment of recurrent previously coiled anterior circulation aneurysm with minimally invasive keyhole craniotomy: report of two cases.

The use of minimally invasive techniques has not yet been reported for the treatment of recurrent aneurysms after coil embolization. A 47-year-old man with a long history of headaches had an anterior communicating aneurysm that had previously been coil embolized. Three-year follow-up angiography showed a significant recurrence. A 50-year-old woman with subarachnoid hemorrhage and acute visual loss underwent coil embolization of a large ophthalmic artery aneurysm, which recurred 3 months later. In both cases, a keyhole fronto-orbital one-piece craniotomy was performed. In the first patient, the aneurysm was clip ligated. The coil mass, which had eroded through the dome, was excised. In the second patient, the anterior clinoid was removed and the aneurysm was clip ligated. Postoperative angiography showed no residual aneurysm and no evidence of branch or parent vessel compromise in either patient. Both patients had an uncomplicated postoperative course. Recurrent previously coiled aneurysms are technically challenging to treat. A minimal fronto-orbital craniotomy provides a sufficiently capacious working space for successful treatment of some recurrent aneurysms of the anterior circulation.

Interferon enhances the activity of the anticancer ribonuclease, onconase.

Interferons (IFN) are biologic agents involved in the antiviral response and the inhibition of tumor growth. Biochemical pathways of IFN action include the double-stranded RNA-activated oligoadenylate synthetase, RNase L, and double-stranded RNA-dependent protein kinase (PKR). Extracellular ribonucleases, especially onconase, also display antiviral and antitumor properties and involve degradation of RNA. We find that IFN increases the anticancer activity of onconase. These two agents work synergistically, and the effect is seen at the level of translation probably because of the degradation of tRNA.

Skeletal muscle-specific immunotoxin for the treatment of focal muscle spasm.

Intramuscular injection of botulinum toxin type A (BTX) is used to treat many disorders characterized by muscular spasms. The utility of BTX, however, is limited by its short duration of action, the development of resistance after repeated injections, and cross-reactivity with autonomic neurons. To overcome these limitations, we engineered an immunotoxin (ITX) to damage skeletal muscle fibers selectively by chemically linking a monoclonal antibody against the nicotinic acetylcholine receptor to the toxin ricin. In vitro, the ITX was 20,000-fold more toxic to myotubes than myoblasts, consistent with the degree of acetylcholine receptor expression. The gastrocnemius muscles of 30 rats were unilaterally injected with a series of protein toxins at various concentrations and examined histopathologically 7 and 30 days later. ITX produced destructive myopathic changes at a dose 300-fold less than the maximum tolerated dose. Assessment of rat muscle strength after unilateral gastrocnemius injections showed that ITX was more effective and had a longer duration of action than BTX. ITXs may have potential for the treatment of involuntary muscle spasms.