157 research outputs found

    The initiative and referendum in California: Historically and recently

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    Thesis (B.A.) in Political Science -- University of Illinois at Urbana-Champaign, 1989.Includes bibliographical references (leaves 54-56)Microfiche of typescript. [Urbana, Ill.]: Photographic Services, University of Illinois, U of I Library, [1989]. 2 microfiches (61 frames): negative.s 1989 ilu n

    Aquaglyceroporin PbAQP during intraerythrocytic development of the malaria parasite Plasmodium berghei

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    The malaria parasite can use host plasma glycerol for lipid biosynthesis and membrane biogenesis during the asexual intraerythrocytic development. The molecular basis for glycerol uptake into the parasite is undefined. We hypothesize that the Plasmodium aquaglyceroporin provides the pathway for glycerol uptake into the malaria parasite. To test this hypothesis, we identified the orthologue of Plasmodium falciparum aquaglyceroporin (PfAQP) in the rodent malaria parasite, Plasmodium berghei (PbAQP), and examined the biological role of PbAQP by performing a targeted deletion of the PbAQP gene. PbAQP and PfAQP are 62% identical in sequence. In contrast to the canonical NPA (Asn-Pro-Ala) motifs in most aquaporins, the PbAQP has NLA (Asn-Leu-Ala) and NPS (Asn-Leu-Ser) in those positions. PbAQP expressed in Xenopus oocytes was permeable to water and glycerol, suggesting that PbAQP is an aquaglyceroporin. In P. berghei, PbAQP was localized to the parasite plasma membrane. The PbAQP-null parasites were viable; however, they were highly deficient in glycerol transport. In addition, they proliferated more slowly compared with the WT parasites, and mice infected with PbAQP-null parasites survived longer. Taken together, these findings suggest that PbAQP provides the pathway for the entry of glycerol into P. berghei and contributes to the growth of the parasite during the asexual intraerythrocytic stages of infection. In conclusion, we demonstrate here that PbAQP plays an important role in the blood-stage development of the rodent malaria parasite during infection in mice and could be added to the list of targets for the design of antimalarial drugs

    Mesenchymal Stromal Cells Improve Salivary Function and Reduce Lymphocytic Infiltrates in Mice with Sjögren's-Like Disease

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    Non-obese diabetic (NOD) mice develop Sjögren's-like disease (SS-like) with loss of saliva flow and increased lymphocytic infiltrates in salivary glands (SGs). There are recent reports using multipotent mesenchymal stromal cells (MSCs) as a therapeutic strategy for autoimmune diseases due to their anti-inflammatory and immunomodulatory capabilities. This paper proposed a combined immuno- and cell-based therapy consisting of: A) an injection of complete Freund's adjuvant (CFA) to eradicate autoreactive T lymphocytes, and B) transplantations of MSCs to reselect lymphocytes. The objective of this was to test the effectiveness of CD45(-)/TER119(-) cells (MSCs) in re-establishing salivary function and in reducing the number of lymphocytic infiltrates (foci) in SGs. The second objective was to study if the mechanisms underlying a decrease in inflammation (focus score) was due to CFA, MSCs, or CFA+MSCs combined.Donor MSCs were isolated from bones of male transgenic eGFP mice. Eight week-old female NOD mice received one of the following treatments: insulin, CFA, MSC, or CFA+MSC (combined therapy). Mice were followed for 14 weeks post-therapy. CD45(-)/TER119(-) cells demonstrated characteristics of MSCs as they were positive for Sca-1, CD106, CD105, CD73, CD29, CD44, negative for CD45, TER119, CD11b, had high number of CFU-F, and differentiated into osteocytes, chondrocytes and adipocytes. Both MSC and MSC+CFA groups prevented loss of saliva flow and reduced lymphocytic infiltrations in SGs. Moreover, the influx of T and B cells decreased in all foci in MSC and MSC+CFA groups, while the frequency of Foxp3(+) (T(reg)) cell was increased. MSC-therapy alone reduced inflammation (TNF-α, TGF-β), but the combination of MSC+CFA reduced inflammation and increased the regenerative potential of SGs (FGF-2, EGF).The combined use of MSC+CFA was effective in both preventing saliva secretion loss and reducing lymphocytic influx in salivary glands

    The FERM and PDZ Domain-Containing Protein Tyrosine Phosphatases, PTPN4 and PTPN3, Are Both Dispensable for T Cell Receptor Signal Transduction

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    PTPN3 and PTPN4 are two closely-related non-receptor protein tyrosine phosphatases (PTP) that, in addition to a PTP domain, contain FERM (Band 4.1, Ezrin, Radixin, and Moesin) and PDZ (PSD-95, Dlg, ZO-1) domains. Both PTP have been implicated as negative-regulators of early signal transduction through the T cell antigen receptor (TCR), acting to dephosphorylate the TCRζ chain, a component of the TCR complex. Previously, we reported upon the production and characterization of PTPN3-deficient mice which show normal TCR signal transduction and T cell function. To address if the lack of a T cell phenotype in PTPN3-deficient mice can be explained by functional redundancy of PTPN3 with PTPN4, we generated PTPN4-deficient and PTPN4/PTPN3 double-deficient mice. As in PTPN3 mutants, T cell development and homeostasis and TCR-induced cytokine synthesis and proliferation were found to be normal in PTPN4-deficient and PTPN4/PTPN3 double-deficient mice. PTPN13 is another FERM and PDZ domain-containing non-receptor PTP that is distantly-related to PTPN3 and PTPN4 and which has been shown to function as a negative-regulator of T helper-1 (Th1) and Th2 differentiation. Therefore, to determine if PTPN13 might compensate for the loss of PTPN3 and PTPN4 in T cells, we generated mice that lack functional forms of all three PTP. T cells from triple-mutant mice developed normally and showed normal cytokine secretion and proliferative responses to TCR stimulation. Furthermore, T cell differentiation along the Th1, Th2 and Th17 lineages was largely unaffected in triple-mutants. We conclude that PTPN3 and PTPN4 are dispensable for TCR signal transduction

    Enhancement of Both Long-Term Depression Induction and Optokinetic Response Adaptation in Mice Lacking Delphilin

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    In the cerebellum, Delphilin is expressed selectively in Purkinje cells (PCs) and is localized exclusively at parallel fiber (PF) synapses, where it interacts with glutamate receptor (GluR) δ2 that is essential for long-term depression (LTD), motor learning and cerebellar wiring. Delphilin ablation exerted little effect on the synaptic localization of GluRδ2. There were no detectable abnormalities in cerebellar histology, PC cytology and PC synapse formation in contrast to GluRδ2 mutant mice. However, LTD induction was facilitated at PF-PC synapses in Delphilin mutant mice. Intracellular Ca2+ required for the induction of LTD appeared to be reduced in the mutant mice, while Ca2+ influx through voltage-gated Ca2+ channels and metabotropic GluR1-mediated slow synaptic response were similar between wild-type and mutant mice. We further showed that the gain-increase adaptation of the optokinetic response (OKR) was enhanced in the mutant mice. These findings are compatible with the idea that LTD induction at PF-PC synapses is a crucial rate-limiting step in OKR gain-increase adaptation, a simple form of motor learning. As exemplified in this study, enhancing synaptic plasticity at a specific synaptic site of a neural network is a useful approach to understanding the roles of multiple plasticity mechanisms at various cerebellar synapses in motor control and learning
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