Evaluation of the Sysmex XN-550, a Novel Compact Haematology analyser from the XN-L® series, compared to the XN-20 system.

INTRODUCTION: The XN-550 is a new, automated, compact, haematology analyser designed to generate a full blood count with a standard five-part white blood cell differential and an immature granulocyte count, as well as an optional reticulocyte and optical platelet (PLT) counts. The aim of the study was to evaluate the performance of the XN-550 and compare it to the established XN-20 system. METHODS: We evaluated the basic parameter and special measurement channels of the XN-550, using the XN-20 (which has a similar operating system), as a reference analyser. Precision, carry-over and throughput evaluations were performed. In addition, a total of 202 samples including normal controls and various pathological samples were studied for comparability. RESULTS: Good correlations with the reference analyser were obtained for all parameters except basophils. The XN-550 offers impedance and optical PLT counts and the latter showed a better correlation and less scatter than the impedance count and was comparable to the XN-20 fluorescent count at PLT counts ≤40×109 /L. Precision was good, and no significant carry-over was detected. CONCLUSIONS: The XN-550 was simple and easy to use, while maintaining the good diagnostic sensitivity seen with high-range systems such as the XN-20, making this compact device suitable for near-patient services and smaller satellite laboratories.

An examination of MS candidate genes identified as differentially regulated in multiple sclerosis plaque tissue, using absolute and comparative real-time Q-PCR analysis.

In our laboratory, we have developed methods in real-time detection and quantitative-polymerase chain reaction (Q-PCR) to analyse the relative levels of gene expression in post mortem brain tissues. We have then applied this method to examine differences in gene activity between normal white matter (NWM) and plaque tissue from multiple sclerosis (MS) patients. Genes were selected based on their association with pathology and through identification by previously conducted global gene expression analysis. Plaque tissue was obtained from secondary progressive (SP) patients displaying chronic active, as well as acute pathologies; while NWM from the same location was obtained from age- and sex-matched controls (normal patients). In this study, we used both SYBR Green I supplementation and commercially available mixes to assess both comparative and absolute levels of gene activity. The results of both methods compared favourably for four of the five genes examined (P < 0.05, Pearsons), while differences in gene expression between chronic active and acute pathologies were also identified. For example, a >50-fold increase in osteopontin (Spp1) and inositol 1-4-5 phosphate 3 kinase B (Itpkb) levels in acute plaques contrasted with the 5-fold or less increase in chronic active plaques (P < 0.05, unpaired t test). By contrast, there was no significant difference in the levels of the MS marker and calcium-dependent protease (Calpain, Capns1) in MS plaque tissue. In summary, Q-PCR analysis using SYBR Green I has allowed us to economically obtain what may be clinically significant information from small amounts of the CNS, providing an opportunity for further clinical investigations.

Hypertolerance to morphine in G(z alpha)-deficient mice.

Our laboratory has generated a mouse deficient in the alpha (alpha) subunit of the G protein, G(z), (G(z alpha)) gene and we have examined the involvement of G(z alpha) in spinal and supraspinal analgesia and tolerance mechanisms. Spinal analgesia was tested by the response times to heat or cold tail flick times in a water bath at 50 degrees C or -5 degrees C and supraspinal analgesia was tested by the times for paw licking and jumping from a plate at 52 degrees C or 0.5 degrees C. Tolerance to morphine was induced in wild type and G(z alpha)-deficient mice over a 5 day period and the behavioral tests were performed daily. The tail flick reaction times to both hot and cold stimuli did not differ between the wild type and G(z alpha)-deficient mice. Analysis of the reaction times from the hot and cold plate tests showed the G(z alpha)-deficient mice developed tolerance to morphine to a greater degree and at a faster rate than wild type mice. Opioid binding assays were performed on synaptic membranes prepared from naive and morphine tolerant wild type and G(z alpha)-deficient brains. No changes in the affinity of morphine for its receptor or in the density of mu and delta opioid receptors were found between the two groups of mice in the naive or morphine tolerant state. This indicates that the absence of G(z alpha) does not affect opioid receptor affinity or receptor up or down regulation. Our results suggest that the presence of G(z alpha) delays the development of morphine tolerance and represents a possible therapeutic target for improving the clinical use of morphine.