Extensive tracheal defects may pose a life-threatening dilemma. Although tracheal transplantation may represent a reconstructive solution, very little is known regarding the immunobiology and behavior of tracheal allografts. The objective of this study was to assess the pattern and kinetics of re-epithelialization of orthotopic tracheal allografts in immunosuppressed recipients. Thirty-eight age-matched mice were randomly assigned to five experimental groups. BALB/c donor tracheal segments were orthotopically transplanted into either syngeneic BALB/c or MHC mismatched allogeneic C57BL/6 recipients with and without immunosuppression. On post-transplant days 7, 14, 28, 48, and 62, animals from each group were evaluated by serial histology, electron microscopy, and serial immunohistochemical analysis for mucosal phenotype, re-epithelialization pattern, and lymphocyte subpopulations. Nonimmunosuppressed recipients underwent recipient-derived basal cell re-epithelialization by Day 48, with differentiation into a sparse population of ciliated columnar epithelium by Day 62, whereas immunosuppressed recipients underwent basal cell re-epithelialization 28 d after transplantation and differentiation into a dense population of ciliated columnar epithelium by Day 48. The re-epithelialization process occurred in a definable pattern that was significantly enhanced with the addition of immunosuppression. Orthotopic tracheal transplants undergo progressive re-epithelialization with recipient-derived basal cells that differentiate into ciliated columnar epithelium in a definable pattern that is enhanced with the addition of immunosuppression.

Airway obliteration characteristic of rejecting heterotopic tracheal allografts does not occur in the orthotopic allografts. Migration of recipient mucosa into the donor allograft appears to prevent airway obliteration in the orthotopic allografts. These findings suggest that the orthotopic tracheal transplantation model more accurately represents the biological behavior of clinical tracheal allografts than the traditional heterotopic model.

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Critically ill patients with ataxia-telangiectasia have complex, multisystem diseases. In this case series, the most common intensive care unit admission diagnosis was respiratory failure. Suspected or confirmed bacterial infections were prevalent. Neuropathologic autopsy findings were similar to those previously reported. Special considerations for the critical care of patients with ataxia-telangiectasia are discussed.

To introduce and assess a system for the delivery of fibroblast growth factor to autologous cartilage grafts using fibrin sealant and analyze whether this "enhancement" results in reduced rates of cartilage resorption and greater preservation of normal architectural features compared with "unenhanced" cartilage grafts. Methods: Auricular cartilage segments measuring 1 cm 2 were harvested from 12 New Zealand white rabbits, morselized, and implanted into the subcutaneous dorsum of the upper back for 3 months. The conditions included (1) cartilage alone; (2) cartilage + fibrin sealant; (3/4) cartilage+acidic or basic fibroblast growth factor (aFGF or bFGF); and (5/6) cartilage + fibrin sealant +aFGF or bFGF. Subsequent to graft harvest, gross and microscopic assessments were performed to assess size, structural integrity, and architectural features, with comparisons performed between each of the conditions. Results: The mean areas of the harvested cartilage grafts treated with fibrin sealant+aFGF or bFGF were 1.23 cm 2 and 1.19 cm 2 , respectively, while the corresponding value

There are currently no descriptions of neonatal tongue anatomy. Therefore, there have been no reports on the morphological differences between it and the adult tongue that would suggest its suitability for suckling. Serial coronal sections of a neonatal tongue were used to create a 3-dimensional model that was compared to that of the adult tongue. Compared to the adult human tongue, the neonatal tongue was found to contain 1) considerably less fat and soft tissue; 2) a thinner mucosa; 3) relatively enlarged extrinsic musculature; 4) a less-developed superior longitudinal muscle, resulting in a flat dorsal surface; and 5) attachments between the extrinsic muscles and the transverse muscle group that have not been identified in the adult tongue. The particular structure of the neonatal tongue suggests how the neonatal tongue is specialized for suckling.

Gene and protein expression are different and distinct between cells treated with docetaxel and cells treated with cisplatin. This finding provides evidence that different molecular pathways leading to cell death are targeted by docetaxel and cisplatin. Future studies focusing on these differentially expressed genes and proteins may improve our understanding, at the molecular level, of the mechanisms responsible for docetaxel-induced apoptosis in cisplatin-resistant HNSCC. Furthermore, these differentially expressed genes and proteins can be exploited as useful surrogate endpoint biomarkers in future clinical trials using docetaxel.

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