Triple collision tumor comprising Merkel cell carcinoma with an unusual immunophenotype, squamous cell carcinoma in situ, and basal cell carcinoma.

Merkel cell carcinoma (MCC) is a rare, aggressive primary cutaneous neuroendocrine cancer which almost always exhibits the cytokeratin (CK)20+/thyroid transcription factor (TTF)-1- immunophenotype. MCC may occur concurrently with squamous cell carcinoma, Bowen disease, and/or basal cell carcinoma (BCC), with some evidence that MCCs which occur in conjunction with other neoplasms exhibit different immunophenotypes compared to pure MCC cases. We present a case of CK20-/TTF-1+ MCC concurrent with Bowen disease and BCC, and discuss possible differences in the pathogenesis of pure vs combined MCC.

Optimization of an augmented Prosperetti-Lezzi bubble model.

Three enhancements are introduced for predicting the violent collapse and rebound of a spherical bubble with the matched-asymptotic-expansion model of Prosperetti and Lezzi [(1986). J. Fluid Mech.

Electron Ionization-Induced Release of Coded Isotopic Reporter Ions in an Zone of Minimal Interference for Quantifiable, Multiplexed GC-MS Analyses.

We describe an isotope coding strategy that enables simultaneous GC-MS analysis of multiple samples for substrate identification and quantification. The method relies on direct measurement of isotopic ethyl carbenium ions serving as mass spectral tags in a zone of minimal interference (ZMI) at m/z 31-37. Sample aldehyde and ketone mixtures were reacted with isotopic 2-aminooxyethyl propionates to illustrate the method, which determined the relative abundance of the mixed compounds with an average 95% accuracy.