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The purpose of this study was to implement a diffusion-weighted sequence for visualisation of mobile lipid resonances (MLR) using high resolution magic angle spinning (HR-MAS) 1H MRS and to evaluate its use in establishing differences between tissues from patients with cervical carcinoma that contain cancer from those that do not. A stimulated echo sequence with bipolar gradients was modified to allow T1 and T2 measurements and optimised by recording signal loss in HR-MAS spectra as a function of gradient strength in model lipids and tissues. Diffusion coefficients, T1 and apparent T2 relaxation times were measured in model lipid systems. MLR profiles were characterised in relation to T1 and apparent T2 relaxation in human cervical cancer tissue samples. Diffusion-weighted (DW) spectra of cervical biopsies were quantified and peak areas analysed using linear discriminant analysis (LDA). The optimised sequence reduced spectral overlap by suppressing signals originating from low molecular weight metabolites and non-lipid contributions. Significantly improved MLR visualisation allowed visualisation of peaks at 0.9, 1.3, 1.6, 2.0, 2.3, 2.8, 4.3 and 5.3 ppm. MLR analysis of DW spectra showed at least six peaks arising from saturated and unsaturated lipids and those arising from triglycerides. Significant differences in samples containing histologically confirmed cancer were seen for peaks at 0.9 ( p < 0.006), 1.3 ( p < 0.04), 2.0 ( p < 0.03), 2.8 ( p < 0.003) and 4.3 ppm ( p < 0.0002). LDA analysis of MLR peaks from DW spectra almost completely separated two clusters of cervical biopsies (cancer, 'no-cancer'), reflecting underlying differences in MLR composition. Generated Receiver Operating Characteristic (ROC) curves and calculated area under the curve (0.962) validated high sensitivity and specificity of the technique. Diffusion-weighting of HR-MAS spectroscopic sequences is a useful method for characterising MLR in cancer tissues and displays an accumulation of lipids arising during tumourigenesis and an increase in the unsaturated lipid and triglyceride peaks with respect to saturated MLR. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An hypothesis relating to the circulation of nitrogen between soil, plants and animals in fertilized grassland is presented. It embodies the results of small-plot experiments and grazing trials on seral grassland in South Africa. Where the value of land is low in comparison with the cost of fertilizer, it is essential that the maximum response be obtained from fertilizer as well as from excretal N. The assumption that 80% of herbage N is returned as excreta, of which 25% is recovered by the grasses in the first season and 25% in the second season, appears to be in accord with liveweight data. Using average values of soil N and fertilizer recovery under local conditions, it is argued that applying 30 lb N per acre (with an initial heavy dressing) should provide higher percentage recoveries of fertilizer N than fixed annual dressings of 60 lb N per acre. In grazing trials over five years, in which these systems are compared, the apparent recoveries of fertilizer N in animal liveweight were respectively 22.4% and 11. 6%. A distinction is drawn between the initial build-up of nitrogen in circulation and the long term maintenance of a nitrogen level providing maximum recovery of fertilizer N. [ABSTRACT FROM AUTHOR]

The blood of 104 medical inpatients was examined at various intervals during storage for 72 hours using a Coulter S counter. Over this period remarkable stability of the white cell count, red cell count, haemoglobin, and mean cell haemoglobin was demonstrated. This permits a useful interpretation of indices obtained in routine postal samples sent to the laboratory by general practitioners for screening. Furthermore, the implications of high correlations between red cell indices in freshly examined blood are considered and the regression line MCV = 2·5 MCH + 16 is derived. Using this relationship the normal range of the Coulter S MCHC is defined as 32·6-33·7 g/dl. The significance of the Coulter MCHC in present-day practice is reassessed and the importance of recognizing values for MCV and MCH not coinciding with the regression line is briefly discussed. [ABSTRACT FROM PUBLISHER]