The Journal of surgical research
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Sentinel node biopsy (SNB) for melanoma, with its intradermal (ID) injection, has a higher success rate than SNB for breast cancer, which is typically performed with a subcutaneous (SC) or peritumor injection. It is hypothesized that this is in part due to a slower transit time of lymphatic mapping agents through the parenchymal lymphatics of the breast. No study has investigated differences in transit time between different tissues to account for this clinical observation. The goal of the study was to compare transit time between ID and SC injections with common agents used in lymphatic mapping. ⋯ Tc99 ID injections were significantly faster than SC injection. The slowest and fastest SC injection agents were unfiltered Tc99 and IB, respectively. Dermal injections provide faster transit of lymphatic agents and may improve the identification rate when applied to patients with breast cancer.
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During reepithelialization, keratinocytes must become activated in order to migrate over the provisional extracellular matrix of the wound. Previously we have shown that focal adhesion kinase (FAK) is induced in activated keratinocytes. The mechanisms responsible for keratinocyte activation are unknown. ⋯ We conclude that FAK is up-regulated in keratinocytes in this whole skin explant model. Furthermore FAK up-regulation and keratinocyte activation are not confined to the migrating cells but are found in cells some distance from the skin margin. These data suggest that (1) cell migration, contact with wound matrix molecules, loss of cell-cell contact, or loss of basement membrane contact is not necessary for FAK up-regulation or keratinocyte activation; and (2) tyrosine kinase signaling pathways are important for reepithelialization.
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In the mid-1990s, the Department of Veterans Affairs (DVA) implemented the Veterans Equitable Resource Allocation (VERA), a new financial model developed to attempt to better distribute the approximately $18 billion annual budget among roughly 170 Veterans Administration Medical Centers (VAMCs). VERA is based on a Health Maintenance Organization (HMO) model. VERA provides reimbursement to each of the 22 regional Veterans Integrated Service Networks (VISNs), and subsequent VISN distribution to individual VAMCs is based on an individual medical center's enrollment of unique social security numbers (uniques). In HMO vocabulary these are individual "covered lives." ⋯ In the VERA model, the reward of a larger annual budget for an individual VAMC or the regional VISN is realized when staffing of VAMCs is minimized, overall provided medical services (especially costly tertiary services) are limited, and the number of covered lives is maximized. A VAMC staffing system that equates medical services delivered in a tertiary VAMC setting based on an HMO model like VERA (where the user population is skewed toward the sicker, older patient) shows decreased correlation when compared with VAMC workload model parameters.