Overexpression of the 18A2/mts1 gene and down–regulation of the TIMP–2 gene in invasive human glioma cell lines in vitro

Invasion of the reconstituted extracellular matrix composite, Matrigel, by eight human glioma–derived cell lines and human fetal brain cells was assessed in vitro using 8 um polycarbonate filters in a modified Boyden migration chamber. With the exception of one low grade glioma derived cell line, all lines studied proved to be invasive while normal fetal brain cells failed to invade. This invasive potential was independent of the histological grade of the tumour from which the cell lines originated. In addition, the expression of the metastasis–associated gene 18A2lmts1 as well as the tissue inhibitor of metalloproteinases–2 (TIMP–2) was analysed in each of the glioma–derived cell lines. The 18A2/mtsl was expressed in all the cells studied with the exception of fetal brain cells and the low grade non–invasive glioma derived IPRK–7 cell line. The 18A2/mtsl related genes coding for the S100 subfamily of calcium binding proteins were found to be differentially and overexpressed in invasive cell lines. TIMP–2 was expressed only in noninvasive cell lines. These results suggest that the 18A2/ mtsl and TIMP–2 genes could play an important role in the invasive behaviour of human glioma cells in vitro. .     

Sonoelasticity of organs: shear waves ring a bell.

Sonoelasticity is the use of ultrasonography to visualize, in real time, the hardness of stiffness of tissues and organs by depicting the tissue's motion in response to an applied vibration source. The applied vibration source is usually of low amplitude and low frequency (less than 0.1 mm displacement and less than 2000 Hz). Under these conditions, the natural vibration response of tissues and whole organs is revealed as a standing wave pattern determined by the low-frequency elastic constants of the tissues and their boundary conditions, factors that are not related to the ultrasonic echogenicity. As a result, hard or dense isoechoic tumors that are undetectable by conventional ultrasonography often can be visualized in sonoelasticity imaging by virtue of their altered vibration response. In this report, we demonstrate the appearance of organs such as the breast, liver, and kidney during real-time, in vivo sonoelasticity imaging. The results show that the shape and location of vibration patterns are dependent on the tissues and vibration frequencies; thus, information about the basic elastic properties of tissues should be obtainable.     

Comparison of Health and Safety Executive and Cumbrian birth cohort studies of risk of leukaemia/non-Hodgkin's lymphoma in relation to paternal preconceptional irradiation.

In 1993, a case-control study by the Health and Safety Executive (HSE) assessed the risk of leukaemia and non-Hodgkin's lymphoma (LNHL) among children of fathers employed at the Sellafield nuclear installation in relation to paternal preconceptional irradiation (PPI). It concluded that the statistical association between risk of LNHL and PPI was confined to children born in the village of Seascale, where the dose-response was extremely high and very significant. In contrast, in 2002, a Cumbrian birth cohort study, investigating largely the same cases, concluded that this statistical association was not significantly different among children born inside and outside Seascale and estimated the dose-response inside Seascale to be much lower. This review makes a detailed comparison of the two studies, considering their design, data and analyses. The differences between their findings are due to: (i) differences in the distribution of offspring-years which are differential with respect to dose category and Seascale birth status, (ii) a non-Seascale high-dose case included in the Cumbrian but not the HSE study, (iii) differences between analyses using categorical and continuous PPI dose and (iv) the presence of Seascale controls with PPI over 200 mSv in the Cumbrian but not the HSE study.     

Investigation of the blood pressure levels of workers occupationally exposed to salt.

Publicity surrounding the salt and hypertension debate evoked fear in workers at a Salt Mine that their working conditions may lead to high blood pressure. A cross-sectional study was carried out to investigate the blood pressure levels of these workers. The blood pressure levels were found not to be raised in comparison with those of a similar group of workers not occupationally exposed to salt.