Citations

OBJECTIVESCD62L was evaluated as a determinant of human pre‐effector T cells.STUDY DESIGN AND SETTINGPhenotype and cytokine secretion profiles of CD62L cells were determined based on activation status.RESULTSCD62LLow T cells demonstrated significantly higher secretion of interleukin (IL)‐10 and interferon (IFN)‐Γ than did CD62LHigh T cells. After activation, the majority of cells expressed high levels of the CD62L surface marker. Postactivation levels of IL‐10 production remained elevated or unchanged. In a murine B16 melanoma model, freshly isolated CD62LLow tumor draining lymph nodes (TDLN) T cells showed increased secretion of IL‐2 and IL‐4 but not of IL‐10 or IFN‐γ. The surface expression of CD62L and cytokine secretion patterns were maintained after activation with concomitant increases in IL‐10.CONCLUSIONOur results provide evidence that CD62LLow T cells in TDLNs of progressively growing squamous cell carcinoma of the head and neck differ phenotypically and functionally from those of mouse origin.SIGNIFICANCECharacterization of this human CD62LLow T cell population provides initial insight regarding novel surface markers in TDLN T cells that might correlate with antitumor reactivity.

OBJECTIVE:Recent studies have identified the capacity of transforming growth factor‐α (TGF‐α) to stimulate mammalian labyrinthine hair cell regeneration after acute ototoxic damage. Augmenting hair cell regeneration with such growth factors may have a role in potentiation of recovery of cochlear function after hair cell injury. Transtympanic application of aqueous solutions to the round window membrane (RWM) has proved successful as a drug delivery route. The purpose of this study was to test the permeability of the mammalian RWM to TGF‐α in an inexpensive and reliable in vitro model.METHODS:Guinea pig RWM niches were harvested and transferred to a 2‐chamber apparatus, and TGF‐α was applied to the middle‐ear side of the chamber. ELISAs of TGF‐α were measured at intervals during a 96‐hour period.RESULTS:Aliquots taken during a 96‐hour interval demonstrated passage of TGF‐α in concentrations sufficient to stimulate hair cell regrowth.CONCLUSIONS:The apparatus allows study of RWM permeability to other substances and provides a basic model for study of RWM physiology. TGF‐α is able to pass through a mammalian RWM.