Cell surface proteins of the neutrophil in relation to chronic myeloid leukaemia

A large number of studies now suggest that non-random chromosomal changes are associated with human cancers. Certain chromosomes are involved more frequently in rearrangements, duplications and deletions than would be expected by chance. The most consistently observed chromosome abnormality is the Philadelphia chromosome, (Ph') which is found in a number of heamopoetic cell lineages in some 90% of patients sufferring from chronic myeloid leukaemia, (CML). Despite the diagnostic significance of the Ph' chromosome virtually nothing is known about its role in the origin and development of the disease. Well established phenotypic alterations in the mature neutrophil in CML are limited to the finding of a reduced level of alkaline phophatase in these cells. However, membrane-related phenomena, including phagocytosis and lectin agglutination have been shown to be altered. This study was undertaken to determine whether simple consistent alterations in cell membrane proteins were detectable at the molecular level which might underlie the membrane-related phenomena noted above and could be related to the chromosomal changes which occur in this leukaemia. Labelling of the membrane proteins of the cell chosen for study, the neutrophil, revealed at least thirteen relatively high molecular weight polypeptides bands which were identified using the 125I-lactoperoxidase labelling technique, on SDS-PAGE. To demonstrate that the labelled polypeptides were present on the cell surface, three independent methods were used: plasma membrane isolation, trypsin sensitivity and labelling in the presence and absence of exogenous enzymes. Extraction with the non-ionic detergent, Triton X-100 considerably reduced problems of handling and proteolytic digestion associated with this cell. Evidence is presented that non-ionic detergents, (TX-100 and NP-40), extract polypeptides selectively which may have structural significance. One major coomassie blue staining band, of mol. wt. 85K, a minor band of mol. wt. 25K and one broad radiolabelled band of mol. wt. 55-60K were particularly selectively retained in a residual pellet. Experiments using Concanavalin A (Con A) affinity chromatography showed that most of the labelled polypeptides were glycosylated. One major band was unique in that it showed no binding to Con A either by affinity chromatography or by the use of 125I-Con A overlay on SDS-PAGE. It is the major cell surface receptor for Wheat Germ Agglutinin (WGA) which binds to terminal sialic acid residues. when labelled cells were treated with neuraminidase there was an apparent decrease in the mobility of this polypeptide and binding to WGA was abolished. No other labelled band showed significant alteration following neuraminidase treatment. The above evidence suggests that this glycoprotein of mol. wt. 115K approx., (Gp 115K), is the major sialoglycoprotein at the cell surface of the human neutrophil. This finding may be of general interest since it shares a number of the features, described above, with other 'glycophorin-like' sialoglycoproteins reported in the literature. The function of this unusual class of cell surface glycoproteins is not clear, but they appear to make a significant contribution to the net negative charge at the cell surface and to lack secondary or tertiary structure in the extracellular portion. Membrane related phenomena of the human neutrophil appear to undergo alterations in CML. Cell surface polypeptides were labelled directly using the 125I-LPO method and radio-labelled lectins (Con A and WGA) were overlayed on whole cell detergent extracts run on SDS-PAGE, in order to try and detect alterations in glycosylation. The results suggest that large scale alterations in the expression of glycosylated, and in particular cel1-surface, proteins do not occur. No evidence for novel gene products or marked alteration in glycosylation of neutrophils in CML was found

Effects of negative energy balance on liver gene and protein expression during the early postpartum period and its impacts on dairy cow fertility

End of project reportNegative energy balance (NEB) is a severe metabolic affecting high yielding dairy cows early post partum with both concurrent and latent negative effects on cow fertility as well as on milk production and cow health. The seasonal nature of Irish dairy production necessitates high cow fertility and a compact spring calving pattern in order to maximise grass utilisation. Poor dairy cow reproductive performance currently costs the Irish cattle industry in excess of €400 million annually. High milk yields have been associated with lower reproductive efficiency, and it has been suggested that this effect is probably mediated through its effects on the energy balance of the cow during lactation. The modern high genetic merit dairy cow prioritises nutrient supply towards milk production in early lactation and this demand takes precedence over the provision of optimal conditions for reproduction. In this study we used the bovine Affymetrix 23,000 gene microarray, which contains the most comprehensive set of bovine genes to be assembled and provides a means of investigating the modifying influences of energy balance on liver gene expression. Cows in severe negative energy balance (SNEB) in early lactation showed altered hepatic gene expression in metabolic processes as well as a down regulation of the insulin-like growth factor (IGF) system, where insulin like growth factor-1 (IGF-1), growth hormone receptor variant 1A (GHR1A) and insulin-like growth factor binding protein-acid labile subunit (IGFBP-ALS) were down regulated compared to the cows in the moderate negative energy balance MNEB group, consistent with a five-fold reduction in systemic concentrations of IGF1 in the SNEB group.Cows in SNEB showed elevated expression of key genes involved in the inflammatory response such as interleukin-8 (IL-8). There was a down regulation of genes involved in cellular growth in SNEB cows and moreover a negative regulator of cellular proliferation (HGFIN) was up regulated in SNEB cows, which is likely to compromise adaptation and recovery from NEB. The puma method of analysis revealed that 417 genes were differentially regulated by EB (P<0.05), of these genes 190 were up-regulated while 227 were down-regulated, with 405 genes having known biological functions. From Ingenuity Pathway Analysis (IPA), lipid catabolism was found to be the process most affected by differences in EB status

Polarization transfer in the 4^{4}He(e⃗,e′p⃗3(\vec{e},e' \vec{p}^{3}H reaction

Polarization transfer in the 4He(e,e'p)3H reaction at a Q^2 of 0.4 (GeV/c)^2 was measured at the Mainz Microtron MAMI. The ratio of the transverse to the longitudinal polarization components of the ejected protons was compared with the same ratio for elastic ep scattering. The results are consistent with a recent fully relativistic calculation which includes a predicted medium modification of the proton form factor based on a quark-meson coupling model.Comment: 5 pages, Latex, 2 postscript figures, submitted to Physics Letters

Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in $^{208}$Tl and $^{214}$Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 $m^2$ of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in $^{208}$Tl. After more than one year of background measurement, a surface activity of the scintillators of $\mathcal{A}$($^{208}$Tl) $=$ 1.5 $\mu$Bq/m$^2$ is reported here. Given this level of background, a larger BiPo detector having 12 m$^2$ of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of $\mathcal{A}$($^{208}$Tl) $<$ 2 $\mu$Bq/kg (90% C.L.) with a six month measurement.Comment: 24 pages, submitted to N.I.M.

Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors

We have constructed a GEANT4-based detailed software model of photon transport in plastic scintillator blocks and have used it to study the NEMO-3 and SuperNEMO calorimeters employed in experiments designed to search for neutrinoless double beta decay. We compare our simulations to measurements using conversion electrons from a calibration source of $\rm ^{207}Bi$ and show that the agreement is improved if wavelength-dependent properties of the calorimeter are taken into account. In this article, we briefly describe our modeling approach and results of our studies.Comment: 16 pages, 10 figure

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure