Mice deficient in interleukin-4 (IL-4) or IL-4 receptor alpha have higher resistance to sporozoite infection with Plasmodium berghei (ANKA) than do naive wild-type mice

BALB/c interleukin-4 (IL-4(-/-)) or IL-4 receptor-alpha (IL-4ralpha(-/-)) knockout (KO) mice were used to assess the roles of the IL-4 and IL-13 pathways during infections with the blood or liver stages of plasmodium in murine malaria. Intraperitoneal infection with the blood-stage erythrocytes of Plasmodium berghei (ANKA) resulted in 100% mortality within 24 days in BALB/c mice, as well as in the mutant mouse strains. However, when infected intravenously with the sporozoite liver stage, 60 to 80% of IL-4(-/-) and IL-4ralpha(-/-) mice survived, whereas all BALB/c mice succumbed with high parasitemia. Compared to infected BALB/c controls, the surviving KO mice showed increased NK cell numbers and expression of inducible nitric oxide synthase (iNOS) in the liver and were able to eliminate parasites early during infection. In vivo blockade of NO resulted in 100% mortality of sporozoite-infected KO mice. In vivo depletion of NK cells also resulted in 80 to 100% mortality, with a significant reduction in gamma interferon (IFN-gamma) production in the liver. These results suggest that IFN-gamma-producing NK cells are critical in host resistance against the sporozoite liver stage by inducing NO production, an effective killing effector molecule against Plasmodium. The absence of IL-4-mediated functions increases the protective innate immune mechanism identified above, which results in immunity against P. berghei infection in these mice, with no major role for IL-13.

Review of the implementation of recommendations relating to the death of Representative Leo J. Ryan [microform] : hearings before the Subcommittee on International Operations of the Committee on Foreign Affairs, House of Representatives, Ninety-sixth Congress, February 20 and March 4, 1980.

Reuse of record except for individual research requires license from Congressional Information Service, Inc.

Christ the resurrection and the life : a sermon, preached on the occasion of the death of Rev. David S. Bogart, on the evening of Aug. 4, 1839, in the Middle Dutch Church /

Published by request.

A foure-fould meditation, of the foure last things : viz. ... 1. Houre of death. 2. Day of iudgement. 3. Paines of hell. 4. Ioyes of heauen. Shewing the estate of the elect and reprobate : composed in a divine poeme by R. S. The author of S. Peters complaint. Robert Southwell, S. J. Imprinted at London by G. Eld: for Francis Burton. 1606. With a bibliographical preface by Charles Edmonds ... .

Mode of access: Internet.

Isolation and characterization at cholinergic nicotinic receptors of a neurotoxin from the venom of the Acanthophis sp Seram death adder

The present study describes the isolation of the first neurotoxin (acantoxin IVa) from Acanthophis sp. Seram death adder venom and an examination of its activity at nicotinic acetylcholine receptor (naChR) subtypes. Acantoxin IVa (MW 6815; 0.1-1.0 muM) caused concentration-dependent inhibition of indirect twitches (0.1 Hz, 0.2 ms, supramaximal V) and inhibited contractile responses to exogenous nicotinic agonists in the chick biventer cervicis nerve-muscle, confirming that this toxin is a postsynaptic neurotoxin. Acantoxin IVa (1-10 nM) caused pseudo-irreversible antagonism at skeletal muscle nAChR with an estimated pA(2) Of 8.36 +/- 0.17. Acantoxin IVa was approximately two-fold less potent than the long-chain (Type 11) neurotoxin, alpha-bungarotoxin. With a pK(i) value of 4.48, acantoxin IVa was approximately 25,000 times less potent than a-bungarotoxin at alpha7-type neuronal nAChR. However, in contrast to alpha-bungarotoxin, acantoxin IVa completely inhibited specific [H-3]-methyllycaconitine (MLA) binding in rat hippocampus homogenate. Acantoxin IVa had no activity at ganglionic nAChR, alpha4beta2 subtype neuronal nAChR or cytisine-resistant [H-3]-epibatidine binding sites. While long-chain neurotoxin resistant [H-3]-MLA binding in hippocampus homogenate requires further investigation, we have shown that a short-chain (Type 1) neurotoxin is capable of fully inhibiting specific [H-3]-MLA binding. (C) 2004 Elsevier Inc. All rights reserved.

The role of neurotransmission and the Chopper domain in p75 neurotrophin receptor death signaling

The role of p75 neurotrophin receptor (p75(NTR)) in mediating cell death is now well charaterized, however, it is only recently that details of the death signaling pathway have become clearer. This review focuses on the importance of the juxtamembrane Chopper domain region of p75(NTR) in this process. Evidence supporting the involvement of K+ efflux, the apoptosome (caspase-9, apoptosis activating factor-1, APAF-1, and Bcl-(xL)), caspase-3, c-jun kinase, and p53 in the p75(NTR) cell death pathway is discussed and regulatory roles for the p75(NTR) ectodomain and death domain are proposed. The role of synaptic activity is also discussed, in particular the importance of neutrotransmitter-activated K+ channels acting as the gatekeepers of cell survival decisions during development and in neurodegenerative conditions.

beta 2 subunit contribution to 4/7 alpha-conotoxin binding to the nicotinic acetylcholine receptor

The structures of acetylcholine-binding protein ( AChBP) and nicotinic acetylcholine receptor ( nAChR) homology models have been used to interpret data from mutagenesis experiments at the nAChR. However, little is known about AChBP-derived structures as predictive tools. Molecular surface analysis of nAChR models has revealed a conserved cleft as the likely binding site for the 4/7 alpha-conotoxins. Here, we used an alpha 3 beta 2 model to identify beta 2 subunit residues in this cleft and investigated their influence on the binding of alpha-conotoxins MII, PnIA, and GID to the alpha 3 beta 2 nAChR by two-electrode voltage clamp analysis. Although a beta 2-L119Q mutation strongly reduced the affinity of all three alpha-conotoxins, beta 2-F117A, beta 2-V109A, and beta 2-V109G mutations selectively enhanced the binding of MII and GID. An increased activity of alpha-conotoxins GID and MII was also observed when the beta 2-F117A mutant was combined with the alpha 4 instead of the alpha 3 subunit. Investigation of A10L-PnIA indicated that high affinity binding to beta 2-F117A, beta 2-V109A, and beta 2-V109G mutants was conferred by amino acids with a long side chain in position 10 (PnIA numbering). Docking simulations of 4/7 alpha-conotoxin binding to the alpha 3 beta 2 model supported a direct interaction between mutated nAChR residues and alpha-conotoxin residues 6, 7, and 10. Taken together, these data provide evidence that the beta subunit contributes to alpha-conotoxin binding and selectivity and demonstrate that a small cleft leading to the agonist binding site is targeted by alpha-conotoxins to block the nAChR.

Transcription factor Tfec contributes to the IL-4-inducible expression of a small group of genes in mouse macrophages including the granulocyte colony-stimulating factor receptor

Expression of the mouse transcription factor EC (Tfec) is restricted to the myeloid compartment, suggesting a function for Tfec in the development or function of these cells. However, mice lacking Tfec develop normally, indicating a redundant role for Tfec in myeloid cell development. We now report that Tfec is specifically induced in bone marrow-derived macrophages upon stimulation with the Th2 cytokines, IL-4 and IL-13, or LPS. LPS induced a rapid and transient up-regulation of Tfec mRNA expression and promoter activity, which was dependent on a functional NF-kappa B site. IL-4, however, induced a rapid, but long-lasting, increase in Tfec mRNA, which, in contrast to LPS stimulation, also resulted in detectable levels of Tfec protein. IL-4-induced transcription of Tfec was absent in macrophages lacking Stat6, and its promoter depended on two functional Stat6-binding sites. A global comparison of IL-4-induced genes in both wild-type and Tfec mutant macrophages revealed a surprisingly mild phenotype with only a few genes affected by Tfec deficiency. These included the G-CSFR (Csf3r) gene that was strongly up-regulated by IL-4 in wild-type macrophages and, to a lesser extent, in Tfec mutant macrophages. Our study also provides a general definition of the transcriptome in alternatively activated mouse macrophages and identifies a large number of novel genes characterizing this cell type.

The role of group I metabotropic glutamate receptor's in neuronal excitotoxicity in Alzheimer's disease

Neurodegenerative diseases such as Huntington's disease, ischemia, and Alzheimer's disease (AD) are major causes of death. Recently, metabotropic glutamate receptors (mGluRs), a group of seven-transmembrane-domain proteins that couple to G-proteins, have become of interest for studies of pathogenesis. Group I mGluRs control the levels of second messengers such as inositol 1,4,5-triphosphate (IP3) Cal(2+) ions and cAMP. They elicit the release of arachidonic acid via intracellular Ca2+ mobilization from intracellular stores such as mitochondria and endoplasmic reticulum. This facilitates the release of glutamate and could trigger the formation of neurofibrillary tangles, a pathological hallmark of AD. mGluRs regulate neuronal injury and survival, possibly through a series of downstream protein kinase and cysteine protease signaling pathways that affect mitochondrially mediated programmed cell death. They may also play a role in glutamate-induced neuronal death by facilitating Cal(2+) mobilization. Hence, mGluRs have become a target for neuroprotective drug development. They represent a pharmacological path to a relatively subtle amelioration of neurotoxicity because they serve a modulatory rather than a direct role in excitatory glutamatergic transmission.

Combinatorial solid phase synthesis of multiply substituted 1,4-benzodiazepines and affinity studies on the CCK2 receptor (Part 1)

One hundred sixty-eight multiply substituted 1,4-benzodiazepines have been prepared by a five-step solid-phase combinatorial approach using syn-phase crowns as a solid support and a hydroxymethyl-phenoxy-acetamido linkage (Wang linker). The substituents of the 1,4-benzodiazepine scaffold have been varied in the -3, -5, -7, and 8-positions and the combinatorial library was evaluated in a cholecystokinin (CCK) radioligand binding assay. 3-Alkylated 1,4-benzodiazepines with selectivity towards the CCK-B (CCK2) receptor have been optimized on the lipophilic side chain, the ketone moiety, and the stereochemistry at the 3-position. Various novel 3-alkylated compounds were synthesized and [S]3-propyl-5-phenyl-1,4-benzodiazepin-2-one, [S]NV-A, has shown a CCK-B selective binding at about 180 nM. Fifty-eight compounds of this combinatorial library were purified by preparative TLC and 25 compounds were isolated and fully characterized by TLC, IR, APCI-MS, and 1H/13C-NMR spectroscopy.

Synthesis and evaluation of N1-substituted-3-propyl-1,4-benzodiazepine-2-ones as cholecystokinin (CCK2) receptor ligands

A novel synthetic approach towards N1-alkylated 3-propyl-1,4-benzodiazepines was developed in five synthetic steps from 2-amino-4-chlorobenzophenone, in which the N-oxide 4 served as a key intermediate. The structure-activity relationship optimization of this 3-prophyl-1,4-benzodiazepine template was carried out on the N1-position by selective alkylation reactions and resulted in a ligand with an improved affinity on the cholecystokinin (CCK2) receptor. The N-allyl-3-propyl-benzodiazepine 6d displayed an affinity towards the CCK2 (CCK-B) receptor of 170 nM in a radiolabelled receptor-binding assay. The anxiolytic activity of this allyl-3-propyl-1,4-benzodiazepine 6d was subsequently determined in in-vivo psychotropic assays. This novel ligand had ED50 values of 4.7 and 5.2 mg kg-1 in the black and white box test and the x-maze, respectively, and no significant sedation/muscle relaxation was observed.