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951.
MR Roberts KS Cooke AC Tran KA Smith WY Lin M Wang TJ Dull D Farson KM Zsebo MH Finer 《Canadian Metallurgical Quarterly》1998,161(1):375-384
TCR- and IgG-binding Fc receptors (Fc gamma R) mediate a variety of critical biologic activities including cytolysis via the structurally related zeta- and gamma-chains. In previous studies, we have described chimeric immune receptors (CIR) in which the ligand-binding domain of a heterologous receptor or Ab is fused directly to the cytoplasmic domain of the TCR zeta-chain. Such zeta-CIRs efficiently trigger cytotoxic function of both T and NK cells in a target-specific manner. In this report, we compared the ability of both zeta- and gamma-CIRs to activate the cytolytic function of two distinct classes of Fc gamma R-bearing effectors, NK cells and neutrophils. Mature neutrophils expressing zeta- and gamma-CIR were generated in vivo from murine hemopoietic stem cells following transplantation of syngeneic mice with retrovirally transduced bone marrow or in vitro from transduced human CD34+ progenitors following differentiation. Both zeta- and gamma-based CIRs were capable of activating target-specific cytolysis by both NK cells and neutrophils, although the zeta-CIR was consistently more efficient. The experimental approach described is a powerful one with which to study the role of nonlymphoid effector cells in the host immune system and permits the rational design of immunotherapeutic strategies that rely on harnessing multiple immune cell functions via CIR-modified hemopoietic stem cells or progenitors. 相似文献
952.
Islet cell ontogeny will define adult beta-cell mass and will consist of a balance of islet cell birth and death. We have investigated the ontogeny of factors that may be related to developmental apoptosis in the islets, insulin-like growth factor II (IGF-II) and inducible nitric oxide synthase (iNOS), in pancreata of young Wistar rats. Pancreata were collected from rats of 21 days gestation to 29 days postnatal age. In situ hybridization and immunohistochemistry showed that IGF-II was expressed and present in fetal and neonatal islet cells, but declined rapidly 2 weeks after birth. Little IGF-I was associated with fetal or postnatal islets. Apoptosis in islet cells was visualized by molecular histochemistry for DNA breakage in tissue sections. Apoptosis was low in the fetus, but increased in incidence postnatally so that 13% of islet cells were undergoing apoptosis on postnatal day 14, with the incidence declining thereafter. Immunohistochemistry for iNOS showed that it was expressed within beta-cells and was most abundant 12 days after birth. When islets were isolated from rat pancreata 20-22 days after birth, islet cell viability, DNA synthetic rate, and insulin release were reduced after incubation with interleukin-1beta, tumor necrosis factor, or interferon-gamma. An increased rate of islet cell survival was found after simultaneous incubation with IGF-I or -II. Cytokine-mediated islet cell death involved the induction of apoptosis. Islets isolated from neonatal rats were not killed after exposure to these cytokines at the same concentrations, but cytokine-induced cell death was seen when neonatal islets were incubated with a neutralizing antibody against IGF-II. These experiments show that a peak of islet cell apoptosis that is maximal in the rat pancreas 14 days after birth is temporally associated with a fall in the islet cell expression of IGF-II. IGF-II was shown to function as an islet survival factor in vitro. The induction of islet cell apoptosis in vivo may involve an increased expression of iNOS within beta-cells. 相似文献
953.
E Plassart-Schiess A Gervais B Eymard A Lagueny J Pouget JM Warter M Fardeau TJ Jentsch B Fontaine 《Canadian Metallurgical Quarterly》1998,50(4):1176-1179
Autosomal-dominant and -recessive myotonia congenita are caused by mutations in the skeletal muscle voltage-gated chloride channel gene (CLCN1). We searched for mutations in this gene in 20 unrelated families with myotonia congenita. We identified 11 different mutations in 10 families. Two of five new mutations (Ala313Thr and Ile556Asn) were both autosomal recessive and dominant with either reduced penetrance or incomplete dominance. Mutations in the CLCN1 gene do not therefore necessarily behave in a classic Mendelian manner. 相似文献
954.
Pediocin PA-1 bound to anionic lipid vesicles with saturated or unsaturated fatty acid chains in a lipid concentration-dependent fashion. Little change in binding parameters was observed for zwitterionic lipid vesicles. Decreasing the anionic lipid content of the vesicles gave a higher relative dissociation constant for the peptide-lipid interactions and further supports the electrostatic interaction model of binding. 相似文献
955.
956.
Dinkel J. A. Daniels R. E. Das S. K. Martin J. H. Simanton J. R. Teng L. C. 《IEEE transactions on nuclear science》1965,12(3):27-30
In this paper, we investigate the beam phase damping techniques employed in the ZGS. Phase oscillation frequencies have been measured at various times during acceleration. Response data taken on all systems involved with phase and radial position measurement have been used to calculate the phase and radial position responses. These results compare favorably with responses measured on the ZGS with accelerated beam. 相似文献
957.
Map positions of pet9, pep1 and pdr4 with respect to CEN2. 总被引:2,自引:0,他引:2
958.
959.
J. B. M. Coppock N. W. R. Daniels P. W. Russell Eggitt 《Journal of the American Oil Chemists' Society》1965,42(7):652-656
Lipid extracted from unyeasted wheat flour doughs had earlier yielded hitherto unidentified methyl esters using boron trifluoride
interesterification when the lipid was isolated from aged or chemically oxidized flours or doughs. The identity of one unknown
constituent is shown to be methyl methoxy stearate which could also be an artifact of the interesterification process. Conditions
of formation of the artifact have been carefully studied and statistical analysis of the yields of this substance from the
lipid of naturally aged flour doughs maintains our view of a reversible lipid oxidation stage being involved in natural and
chemical flour maturing in the presence of oxidants in doughmaking. 相似文献
960.
D David M Naito EL Michelson J Morganroth TJ Mardelli T Blenko 《Canadian Metallurgical Quarterly》1981,48(3):468-472
Simultaneous hemodynamic and echocardiographic recordings were used to demonstrate mechanical atrial alternans during programmed atrioventricular (A-V) pacing in five open chest dogs. Each animal was studied in two stages, first with the A-V conduction system intact (phase I) and later after the experimental induction of complete A-V block (phase II). Atrial alternans was demonstrated during rapid atrial stimulation at cycle lengths ranging from 250 to 120 ms. During phase I, rapid atrial pacing resulted in complex combinations of variable A-V conduction disturbances with superimposed atrial and ventricular alternans. During phase II, atrial alternans could be observed during a programmed prolonged pause in ventricular activity. It is anticipated that this method will facilitate recognition of atrial alternans in various clinical situations and shed further light on its possible hemodynamic significance. 相似文献