Millipore Sigma Vibrant Logo
 

qc


93 Results Erweiterte Suche  
Suchergebnisse
Produkte (0)
Dokumente (9)
Seiten (84)

Suche eingrenzen Grenzen Sie Ihre Suche mit den nachstehenden Filtern ein

Dokumententyp

  • (6)
  • (3)
Finden Sie nicht, was Sie suchen?
Kontaktieren Sie bitten
den Kundenservice

 
Benötigen Sie Hilfe, um ein Dokument zu finden?
  • Verwenden Sie die Dokumentensuche, um nach Analysenzertifikaten, Qualitätszertifikaten oder Sicherheitsdatenblättern zu suchen.
  • Wenn Sie bei der Suche einer Gebrauchsanleitung oder eines Benutzerhandbuchs Hilfe benötigen, kontaktieren Sie bitte den Kundenservice.
  • «
  • <
  • 1
  • >
  • »

  • Distinct glutaminyl cyclase expression in Edinger-Westphal nucleus, locus coeruleus and nucleus basalis Meynert contributes to pGlu-Abeta pathology in Alzheimer's disease ... 20383514

    Glutaminyl cyclase (QC) was discovered recently as the enzyme catalyzing the pyroglutamate (pGlu or pE) modification of N-terminally truncated Alzheimer's disease (AD) Abeta peptides in vivo. This modification confers resistance to proteolysis, rapid aggregation and neurotoxicity and can be prevented by QC inhibitors in vitro and in vivo, as shown in transgenic animal models. However, in mouse brain QC is only expressed by a relatively low proportion of neurons in most neocortical and hippocampal subregions. Here, we demonstrate that QC is highly abundant in subcortical brain nuclei severely affected in AD. In particular, QC is expressed by virtually all urocortin-1-positive, but not by cholinergic neurons of the Edinger-Westphal nucleus, by noradrenergic locus coeruleus and by cholinergic nucleus basalis magnocellularis neurons in mouse brain. In human brain, QC is expressed by both, urocortin-1 and cholinergic Edinger-Westphal neurons and by locus coeruleus and nucleus basalis Meynert neurons. In brains from AD patients, these neuronal populations displayed intraneuronal pE-Abeta immunoreactivity and morphological signs of degeneration as well as extracellular pE-Abeta deposits. Adjacent AD brain structures lacking QC expression and brains from control subjects were devoid of such aggregates. This is the first demonstration of QC expression and pE-Abeta formation in subcortical brain regions affected in AD. Our results may explain the high vulnerability of defined subcortical neuronal populations and their central target areas in AD as a consequence of QC expression and pE-Abeta formation.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • ROW1 maintains quiescent centre identity by confining WOX5 expression to specific cells. 25631790

    The quiescent centre (QC) in the Arabidopsis root apical meristem is essential for stem cell organization. Here we show that the loss of REPRESSOR OF WUSCHEL1 (ROW1), a PHD domain-containing protein, leads to QC failure, defects in cell differentiation and ectopic expression of WUSCHEL-RELATED HOMEOBOX 5 (WOX5) in cells that normally express ROW1. The wox5-1/row1-3 double mutants show similar phenotypes to wox5-1 indicating that WOX5 is epistatic to ROW1. ROW1 specifically binds trimethylated histone H3 lysine 4 (H3K4me3) in the WOX5 promoter region to repress its transcription. QC expression of ROW1 results in a wox5-1-like phenotype with undetectable WOX5 transcripts. We propose that ROW1 is essential for QC maintenance and for stem cell niche development through the repression of WOX5 in the proximal meristem.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • Selective hippocampal neurodegeneration in transgenic mice expressing small amounts of truncated Aβ is induced by pyroglutamate-Aβ formation. 21900558

    Posttranslational amyloid-β (Aβ) modification is considered to play an important role in Alzheimer's disease (AD) etiology. An N-terminally modified Aβ species, pyroglutamate-amyloid-β (pE3-Aβ), has been described as a major constituent of Aβ deposits specific to human AD but absent in normal aging. Formed via cyclization of truncated Aβ species by glutaminyl cyclase (QC; QPCT) and/or its isoenzyme (isoQC; QPCTL), pE3-Aβ aggregates rapidly and is known to seed additional Aβ aggregation. To directly investigate pE3-Aβ toxicity in vivo, we generated and characterized transgenic TBA2.1 and TBA2.2 mice, which express truncated mutant human Aβ. Along with a rapidly developing behavioral phenotype, these mice showed progressively accumulating Aβ and pE3-Aβ deposits in brain regions of neuronal loss, impaired long-term potentiation, microglial activation, and astrocytosis. Illustrating a threshold for pE3-Aβ neurotoxicity, this phenotype was not found in heterozygous animals but in homozygous TBA2.1 or double-heterozygous TBA2.1/2.2 animals only. A significant amount of pE3-Aβ formation was shown to be QC-dependent, because crossbreeding of TBA2.1 with QC knock-out, but not isoQC knock-out, mice significantly reduced pE3-Aβ levels. Hence, lowering the rate of QC-dependent posttranslational pE3-Aβ formation can, in turn, lower the amount of neurotoxic Aβ species in AD.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    MAB377
    Produktbezeichnung:
    Anti-NeuN Antibody, clone A60

  • Water quality in patient testing Water quality in patient testing

    Sophisticated diagnostic equipment is designed to improve quality, increase throughput, and manage continued labor shortages. All diagnostic manufacturers can provide the end user with software specifications that simplify automatic sampling and predilution; ensure workflow efficiency with high-speed throughput and performance; provide accuracy in testing with precision optical systems; deliver real-time access and alerts for patient and QC packages; and offer mechanical alerts to any possible instrumentation failures. Additionally, troubleshooting instrumentation, even with the above solution, creates unique challenges for medical technologists. Instrumentation can alert, flag, and warn that something is problematic, but it takes an experienced medical technologist to determine the root cause. One parameter, even though utilized by each end user on any kind of diagnostic instrument, has not been considered: water. Used in a variety of assays, water is a major reagent in clinical chemistry and immunoassay testing. Analytical factors linked to water quality need to be controlled and optimized to reduce the number of test failures. The water quality delivered to the analyzer is as important as any other reagent. Control of bacteria and its by-products with Elix technology and Biopak filters provides the highest quality water to be used in assays sensitive to these contaminants. Control of the water quality eliminates frequent decontamination. This optimizes analyzer performance and reduces downtime that can be costly to the customer and analyzer manufacturer.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    Mehrere
    Produktbezeichnung:
    Mehrere

  • Evaluation of the NucliSens EasyQ HIV-1 v1.1 and RealTime HIV-1 kits for quantitation of HIV-1 RNA in plasma. 19576640

    Human immunodeficiency virus type-1 (HIV-1) RNA viral load is an important biomarker to evaluate the therapeutic efficacy of antiretroviral drugs and to monitor disease progression in HIV-infected individuals. We compared HIV-1 RNA quantitation between two different kits, the NucliSens EasyQ HIV-1 v1.1 (EasyQ, bioMérieux) and RealTime HIV-1 (RealTime, Abbott), using HIV-1 RNA quality control (QC) materials, cell-cultivated viruses, and the plasma samples of 104 patients with HIV. Correlation between the two kits for HIV RNA-1 quantitation with clinical samples was high (R=0.91). Based on results obtained with quality control standards, the reproducibility of the RealTime kit was higher than the EasyQ kit: the viral load value and coefficient of variation of each kit was 4.11+/-0.136 and 3.3% for EasyQ and 3.55+/-0.042 and 1.2% for RealTime, respectively (P0.002). This is the first comparative analysis of the detection limit and reproducibility of two different quantitation kits using clinical plasma samples from Korean HIV-1-infected patients. It will serve a useful reference to determine correction values for each HIV-1 RNA quantitation kits and to choose an appropriate assay kit for each laboratory.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    3110

  • The intermediate filament protein peripherin is the specific interaction partner of mouse BPAG1-n (dystonin) in neurons. 9971739

    The dystonia musculorum (dt) mouse suffers from severe degeneration of primary sensory neurons. The mutated gene product is named dystonin and is identical to the neuronal isoform of bullous pemphigoid antigen 1 (BPAG1-n). BPAG1-n contains an actin-binding domain at its NH2 terminus and a putative intermediate filament-binding domain at its COOH terminus. Because the degenerating sensory neurons of dt mice display abnormal accumulations of intermediate filaments in the axons, BPAG1-n has been postulated to organize the neuronal cytoskeleton by interacting with both the neurofilament triplet proteins (NFTPs) and microfilaments. In this paper we show by a variety of methods that the COOH-terminal tail domain of mouse BPAG1 interacts specifically with peripherin, but in contrast to a previous study (Yang, Y., J. Dowling, Q.C. Yu, P. Kouklis, D.W. Cleveland, and E. Fuchs. 1996. Cell. 86:655-665), mouse BPAG1 fails to associate with full-length NFTPs. The tail domains interfered with the association of the NFTPs with BPAG1. In dt mice, peripherin is present in axonal swellings of degenerating sensory neurons in the dorsal root ganglia and is downregulated even in other neural regions, which have no obvious signs of pathology. Since peripherin and BPAG1-n also display similar expression patterns in the nervous system, we suggest that peripherin is the specific interaction partner of BPAG1-n in vivo.
    Dokumententyp:
    Referenz
    Produkbestellnummer:
    MAB1527
    Produktbezeichnung:
    Anti-Peripherin Antibody, clone 8G2
  • «
  • <
  • 1
  • >
  • »