Syndecan-1 expression has prognostic significance in head and neck carcinoma

The syndecans are a family of cell-surface heparan sulphate proteoglycans that regulate cell behaviour by binding extracellular matrix molecules such as growth factors. The syndecan family has four members, of which syndecan-1 is the most studied and best characterized. We have studied the prognostic significance of syndecan-1 expression in squamous cell carcinoma (SCC) of the head and neck treated with surgery and post-operative radiotherapy. Paraffin-embedded tissue samples taken from 175 patients with primary SCC, followed up from 2 to 15 years after surgery, were studied for expression of syndecan-1 by immunohistochemistry. A low number (≤50%, the median value) of syndecan-1-positive tumour cells was associated with low histological grade of differentiation (P < 0.0001), a large primary tumour size (T1–2 vs T3–4, P = 0.02), positive nodal status (N0 vs N1–3, P = 0.0006), and high clinical stage (stage I or II vs III or IV, P < 0.0001). Low syndecan-1 expression was also associated with unfavourable overall survival in a univariate analysis (P = 0.001). In a multivariate survival analysis, the clinical stage and syndecan-1 expression were the only independent prognostic factors. We conclude that syndecan-1 is a novel prognostic factor in SCC of the head and neck treated with surgery and post-operative radiotherapy. © 1999 Cancer Research Campaig

Why do people use portable air purifiers? Evidence from occupant surveys and air quality monitoring in homes in three European cities

One of the most widely available technologies to clean the air in homes of particulate matter of less than 2.5 µm in diameter (PM2.5), known to have negative health impacts, are portable home air purifiers (HAPs). This paper presents research which (1) explored the effectiveness of HAPs in real-world conditions in 57 homes in three European cities; (2) examined if HAPs affect users’ perceptions of the indoor air quality (IAQ) at home; and (3) considered the motivations for occupants’ operation of HAPs. Results from this study found that PM2.5 concentrations in bedrooms were reduced by 45% to 69%; perceptions of IAQ were not correlated with measured high PM2.5 levels; occupants reported the HAPs to have a ‘cooling’ effect, which may explain why the predominant driver of HAP use was thermal comfort, rather than IAQ, in all three cities. The latter finding was supported by a statistically significant increase in the probability of HAP use with increasing indoor temperatures. If the operation of HAPs can be managed, or fully automated, to reflect indoor air pollution levels rather than thermal conditions, better pollutant reduction would be feasible and their use to reduce PM2.5 may help mitigate the negative health effects of exposure whilst at home

Fas-Mediated Apoptosis Regulates the Composition of Peripheral αβ T Cell Repertoire by Constitutively Purging Out Double Negative T Cells

BACKGROUND: The Fas pathway is a major regulator of T cell homeostasis, however, the T cell population that is controlled by the Fas pathway in vivo is poorly defined. Although CD4 and CD8 single positive (SP) T cells are the two major T cell subsets in the periphery of wild type mice, the repertoire of mice bearing loss-of-function mutation in either Fas (lpr mice) or Fas ligand (gld mice) is predominated by CD4(-)CD8(-) double negative alphabeta T cells that also express B220 and generally referred to as B220+DN T cells. Despite extensive analysis, the basis of B220+DN T cell lymphoproliferation remains poorly understood. In this study we re-examined the issue of why T cell lymphoproliferation caused by gld mutation is predominated by B220+DN T cells. METHODOLOGY AND PRINCIPAL FINDINGS: We combined the following approaches to study this question: Gene transcript profiling, BrdU labeling, and apoptosis assays. Our results show that B220+DN T cells are proliferating and dying at exceptionally high rates than SP T cells in the steady state. The high proliferation rate is restricted to B220+DN T cells found in the gut epithelium whereas the high apoptosis rate occurred both in the gut epithelium and periphery. However, only in the periphery, apoptosis of B220+DN T cell is Fas-dependent. When the Fas pathway is genetically impaired, apoptosis of peripheral B220+DN T cells was reduced to a baseline level similar to that of SP T cells. Under these conditions of normalized apoptosis, B220+DN T cells progressively accumulate in the periphery, eventually resulting in B220+DN T cell lymphoproliferation. CONCLUSIONS/SIGNIFICANCE: The Fas pathway plays a critical role in regulating the tissue distribution of DN T cells through targeting and elimination of DN T cells from the periphery in the steady state. The results provide new insight into pathogenesis of DN T cell lymphoproliferation