Search results for "MICE"
showing 10 items of 6027 documents
Human interleukin-6 facilitates hepatitis B virus infection in vitro and in vivo.
2000
Abstract Background and aim. Research on hepatitis B virus (HBV) infection in vivo has been limited due to the absence of a suitable animal model. We have developed a human–mouse radiation chimera in which normal mice, preconditioned by lethal total body irradiation and radioprotected with SCID mouse bone marrow cells, are permissive for engraftment of human hematopoietic cells and solid tissues. This resulting human–mouse model, which comprises three genetically disparate sources of tissue, is therefore termed Trimera. This study was aimed at assessing the effect of human IL-6 on HBV infection in vivo in Trimera mice. Methods. Trimera mice were transplanted with human liver tissue fragment…
Germinal center B cells govern their own fate via antibody feedback
2013
High-affinity antibodies reenter germinal centers (GCs) and limit antigen access, thus causing sustained directional evolution in GCs toward higher-affinity antibody production.
Localization and interactions of melatonin in dry cholesterol/lecithin mixed reversed micelles used as cell membrane models
2005
The state of melatonin confined in dry cholesterol/lecithin mixed reversed micelles dispersed in CCl4 was investigated using 1H-NMR and FT-IR spectroscopies as a function of the melatonin to lecithin molar ratio (R(MLT)) and of the cholesterol to lecithin molar ratio (R(CHL)). An analysis of experimental results leads to the hypothesis that, independent of R(MLT) and as a consequence of anisotropic melatonin/lecithin, melatonin/cholesterol and cholesterol/lecithin interactions, melatonin is totally solubilized in reversed micelles. Melatonin is mainly located in and oriented in the nanodomain constituted by the hydrophilic groups of cholesterol and lecithin. A competition of melatonin and c…
A plasma protein corona enhances the biocompatibility of Au@Fe3O4 Janus particles
2015
AbstractAu@Fe3O4 Janus particles (JPs) are heteroparticles with discrete domains defined by different materials. Their tunable composition and morphology confer multimodal and versatile capabilities for use as contrast agents and drug carriers in future medicine. Au@Fe3O4 JPs have colloidal properties and surface characteristics leading to interactions with proteins in biological fluids. The resulting protein adsorption layer (“protein corona”) critically affects their interaction with living matter. Although Au@Fe3O4 JPs displayed good biocompatibility in a standardized in vitro situation, an in-depth characterization of the protein corona is of prime importance to unravel underlying mecha…
Retinoids as a Perspective in Treatment of Alzheimer’s Disease
2010
<i>Background:</i> In the past, we demonstrated that the disintegrin metalloproteinase ADAM10 has α-secretase activity in vitro and in cultured cells. We also found out that moderate overexpression of this proteinase inhibits Aβ peptide production and prevents the formation of amyloid plaques in an Alzheimer’s disease (AD) mouse model. Moreover, it corrects early hippocampal defects like LTP impairment and increases cortical synaptogenesis. <i>Objective:</i> Upregulation of ADAM10 might be an alternative approach concerning AD therapy. Our current research therefore focuses on substances and/or pathways which regulate ADAM10 gene expression. <i>Methods:</i&g…
A common virulence plasmid in biotype 2 Vibrio vulnificus and its dissemination aided by a conjugal plasmid.
2007
ABSTRACT Strains of Vibrio vulnificus , a marine bacterial species pathogenic for humans and eels, are divided into three biotypes, and those virulent for eels are classified as biotype 2. All biotype 2 strains possess one or more plasmids, which have been shown to harbor the biotype 2-specific DNA sequences. In this study we determined the DNA sequences of three biotype 2 plasmids: pR99 (68.4 kbp) in strain CECT4999 and pC4602-1 (56.6 kb) and pC4602-2 (66.9 kb) in strain CECT4602. Plasmid pC4602-2 showed 92% sequence identity with pR99. Curing of pR99 from strain CECT4999 resulted in loss of resistance to eel serum and virulence for eels but had no effect on the virulence for mice, an anim…
Prolactin supplementation to culture medium improves beta-cell survival
2010
OBJECTIVES.: Recent studies demonstrated that prolactin (PRL) has beneficial effects on β cells for islet transplantation. We examined the effect of human recombinant PRL (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. MATERIALS AND METHODS.: Each human islet isolated from 14 deceased multiorgan donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500 μg/L) for 48 hr. β-Cell survival and proliferation (BrdU and Ki-67) were determined by laser scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester…
Expression and regulation of mPer1 in immortalized GnRH neurons.
2003
Hypothalamic GnRH (gonadotropin-releasing hormone) neurons play a critical role in the initiation and maintenance of reproduction competence. Using the mouse GnRH neuronal cell line, GT1-7, we have characterized the expression of the gene mPer1, a recognized key element of the mammalian circadian clockwork. Both mPer1 transcripts and the 136 kDa mPER1 gene product could be detected in these cells. Immunocytochemical analysis also confirmed expression of mPER1 both in vitro and in vivo in GnRH neurons. Activation of cyclic AMP signalling pathways in vitro elevated GnRH secretion as well as mPer1 expression and nuclear mPER1 immunoreactivity. As mPER1 is known to feedback on transcriptional a…
Pro-enkephalin opioid peptides are abundant in porcine and bovine splenic nerves, but absent from nerves of rat, mouse, hamster, and guinea-pig spleen
1995
The opioidergic innervation of the mammalian spleen and possible species differences were investigated. Light-microscopic immunohistochemistry revealed that splenic nerves of bovine and porcine spleen, but not of rat, mouse, hamster and guinea-pig spleen contained proenkephalin-derived opioidergic innervation. Immunoreactivity to both prodynorphin and pro-opiomelanocortin was absent from splenic nerves. In bovine and porcine spleen, fibers immunoreactive for met-enkephalin, met-enkephalin-Arg-Phe, met-enkephalin-Arg-Gly-Leu, leu-enkephalin and peptide F formed perivascular plexus, traveled in trabecular connective tissue, and extended into the capsule. Spatial relationships with immune cell…
Transgenic overexpression of corticotropin releasing hormone provides partial protection against neurodegeneration in an in vivo model of acute excit…
2008
Abstract Corticotropin releasing hormone (CRH) is the central modulator of the mammalian hypothalamic–pituitary–adrenal (HPA) axis. In addition, CRH affects other processes in the brain including learning, memory, and synaptic plasticity. Moreover, CRH has been shown to play a role in nerve cell survival under apoptotic conditions and to serve as an endogenous neuroprotectant in vitro . Employing mice overexpressing murine CRH in the CNS, we observed a differential response of CRH-overexpressing mice (CRH-COE hom -Nes) to acute excitotoxic stress induced by kainate compared with controls (CRH-COE con -Nes). Interestingly, CRH-overexpression reduced the duration of epileptic seizures and pre…