Familiarity with the normal CT appearance of the distal thoracic duct can be helpful in differentiating a normal duct from pathologic lesions of the lower neck, such as lymphadenopathy.

The reductive lithiation of alkyl and vinyl phenyl thioethers by aromatic radical anions is shown to be the most general method yet known for preparing organolithiums capable of intramolecular carbometalation of unactivated alkenes to produce five-membered rings and in one case a four-membered ring (in a far higher yield than known cases). The relative rates of cyclization for alkyllithiums are secondary > tertiary > primary, and the yields are very high. In the secondary case, the stereoselectivity is extremely high, producing a cyclopentylmethyllithium with a trans-2-alkyl substituent. A remarkable finding is that for all of the organolithiums a lithium oxyanionic group in the proximal allylic position to the alkene greatly accelerates the cyclization and leads almost exclusively to a trans relationship between the CH(2)Li group and the OLi group, the opposite relationship from that observed in intramolecular carbolithiations by allyllithiums. A mechanistic rationale for this divergence is discussed. One of the two types of proximal homoallylic lithium oxyanions exerts an analogous effect. An intriguing limitation, even occurring with the highly reactive secondary organolithium and in the presence of an allylic oxyanionic group, is the failure of intramolecular carbolithiation when a methyl group is at the terminus of the alkene.

BACKGROUND AND PURPOSE:Prior descriptions of imaging after failed stapes procedures for otosclerosis predated currently available CT technology and/or failed to assess commonly used metallic implants. The purpose of this study was to correlate temporal bone CT findings with clinically and intraoperatively determined causes of surgical failure.

In-office needle arthroscopy offers the potential advantage of reduced injury to intervention time, without the need for advanced imaging. It is particularly appropriate for those with contraindications to advanced imaging and also may reduce the risk of incorrect diagnoses in those situations in which imaging is associated with low sensitivity/specificity. The purpose of this article is to provide a standardized diagnostic approach to needle arthroscopy of the shoulder.

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