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  • Mouse retina explants after long-term culture in serum free medium. 11719023

    The neonatal mouse retina remains viable as an explant in serum-supplemented growth media for more than 4 weeks. Interpretation of drug effects on this tissue is compromised by the enigmatic composition of the serum. We sought to remove this ambiguity by culturing neonatal as well as late postnatal mouse retina in serum-free nutrient medium. In this study three important observations were made, (1) there is histotypic development of neonatal as well as preservation of late postnatal mouse retinal structure during long-term culture in serum-free medium, although the late postnatal tissue tends to show some loss of cells in the outer nuclear layer. (2) Protein expression in explant photoreceptor cells was similar to that in the litter-matched ones, except for green cone opsin and interphotoreceptor retinoid-binding protein, although mRNA of the latter is present at similar amounts as in age-matched in vivo controls. (3) Cells of the inner retina stained by antibodies to calcium-binding proteins display some novel sprouting of processes. The results show that the mouse retina can be cultured as an explant for more than 4 weeks in a serum-free medium. This represents an important step forward because, (1) the possibility of interference of drug effects by unknown serum factors has been eliminated; and (2) the spent culture medium can be analyzed to investigate biomolecules released by the retina in vitro.
    Document Type:
    Reference
    Product Catalog Number:
    MAB1572
    Product Catalog Name:
    Anti-Parvalbumin Antibody

  • APP processing induced by herpes simplex virus type 1 (HSV-1) yields several APP fragments in human and rat neuronal cells. 21085580

    Lifelong latent infections of the trigeminal ganglion by the neurotropic herpes simplex virus type 1 (HSV-1) are characterized by periodic reactivation. During these episodes, newly produced virions may also reach the central nervous system (CNS), causing productive but generally asymptomatic infections. Epidemiological and experimental findings suggest that HSV-1 might contribute to the pathogenesis of Alzheimer's disease (AD). This multifactorial neurodegenerative disorder is related to an overproduction of amyloid beta (Aβ) and other neurotoxic peptides, which occurs during amyloidogenic endoproteolytic processing of the transmembrane amyloid precursor protein (APP). The aim of our study was to identify the effects of productive HSV-1 infection on APP processing in neuronal cells. We found that infection of SH-SY5Y human neuroblastoma cells and rat cortical neurons is followed by multiple cleavages of APP, which result in the intra- and/or extra-cellular accumulation of various neurotoxic species. These include: i) APP fragments (APP-Fs) of 35 and 45 kDa (APP-F35 and APP-F45) that comprise portions of Aβ; ii) N-terminal APP-Fs that are secreted; iii) intracellular C-terminal APP-Fs; and iv) Aβ(1-40) and Aβ(1-42). Western blot analysis of infected-cell lysates treated with formic acid suggests that APP-F35 may be an Aβ oligomer. The multiple cleavages of APP that occur in infected cells are produced in part by known components of the amyloidogenic APP processing pathway, i.e., host-cell β-secretase, γ-secretase, and caspase-3-like enzymes. These findings demonstrate that HSV-1 infection of neuronal cells can generate multiple APP fragments with well-documented neurotoxic potentials. It is tempting to speculate that intra- and extracellular accumulation of these species in the CNS resulting from repeated HSV-1 reactivation could, in the presence of other risk factors, play a co-factorial role in the development of AD.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Activation of the aryl hydrocarbon receptor by a component of cigarette smoke reduces germ cell proliferation in the human fetal ovary. 23979962

    Fetal life is a critical time for female fertility, when germ cells complete proliferation, initiate meiosis and ultimately form the lifetime stock of primordial follicles. Female fertility may be reduced by in utero exposure to cigarette smoke, which contains ligands for the aryl hydrocarbon receptor (AhR). The AhR is a critical regulator of ovarian germ cell survival in mice; thus activation of this receptor in the ovaries of fetuses exposed to maternal cigarette smoke in utero may provide a mechanism by which female fertility is reduced in later life. We have therefore investigated AhR expression in the human fetal ovary, and examined the effects of an AhR ligand present in cigarette smoke, on germ cells in human fetal ovaries cultured in vitro. The results showed that AHR mRNA expression increased 2-fold between first and late second trimester (P = 0.008). AhR protein was confined to germ cells at all gestations, but varied from expression in most germ cells during the first trimester, to only patchy expression by clusters of germ cells at later gestations. Culture of human fetal ovaries with the AhR ligand 9,10-dimethyl-1,2-benzanthracene-3,4-dihydrodiol (DMBA-DHD; a component of cigarette smoke) did not affect germ cell number in vitro, but significantly reduced the proportion of proliferating germ cells by 29% (as assessed by phospho-histone H3 staining (P = 0.04)). Germ cell apoptosis was not significantly affected. These results reveal that germ cells in the human fetal ovary express AhR from the proliferative stage of development through entry into meiosis and beyond, and demonstrate that AhR ligands found in cigarette smoke have the capacity to impair human fetal ovarian germ cell proliferation.
    Document Type:
    Reference
    Product Catalog Number:
    06-570
    Product Catalog Name:
    Anti-phospho-Histone H3 (Ser10) Antibody, Mitosis Marker

  • Coxsackievirus B exits the host cell in shed microvesicles displaying autophagosomal markers. 24722773

    Coxsackievirus B3 (CVB3), a member of the picornavirus family and enterovirus genus, causes viral myocarditis, aseptic meningitis, and pancreatitis in humans. We genetically engineered a unique molecular marker, "fluorescent timer" protein, within our infectious CVB3 clone and isolated a high-titer recombinant viral stock (Timer-CVB3) following transfection in HeLa cells. "Fluorescent timer" protein undergoes slow conversion of fluorescence from green to red over time, and Timer-CVB3 can be utilized to track virus infection and dissemination in real time. Upon infection with Timer-CVB3, HeLa cells, neural progenitor and stem cells (NPSCs), and C2C12 myoblast cells slowly changed fluorescence from green to red over 72 hours as determined by fluorescence microscopy or flow cytometric analysis. The conversion of "fluorescent timer" protein in HeLa cells infected with Timer-CVB3 could be interrupted by fixation, suggesting that the fluorophore was stabilized by formaldehyde cross-linking reactions. Induction of a type I interferon response or ribavirin treatment reduced the progression of cell-to-cell virus spread in HeLa cells or NPSCs infected with Timer-CVB3. Time lapse photography of partially differentiated NPSCs infected with Timer-CVB3 revealed substantial intracellular membrane remodeling and the assembly of discrete virus replication organelles which changed fluorescence color in an asynchronous fashion within the cell. "Fluorescent timer" protein colocalized closely with viral 3A protein within virus replication organelles. Intriguingly, infection of partially differentiated NPSCs or C2C12 myoblast cells induced the release of abundant extracellular microvesicles (EMVs) containing matured "fluorescent timer" protein and infectious virus representing a novel route of virus dissemination. CVB3 virions were readily observed within purified EMVs by transmission electron microscopy, and infectious virus was identified within low-density isopycnic iodixanol gradient fractions consistent with membrane association. The preferential detection of the lipidated form of LC3 protein (LC3 II) in released EMVs harboring infectious virus suggests that the autophagy pathway plays a crucial role in microvesicle shedding and virus release, similar to a process previously described as autophagosome-mediated exit without lysis (AWOL) observed during poliovirus replication. Through the use of this novel recombinant virus which provides more dynamic information from static fluorescent images, we hope to gain a better understanding of CVB3 tropism, intracellular membrane reorganization, and virus-associated microvesicle dissemination within the host.
    Document Type:
    Reference
    Product Catalog Number:
    AB980

  • Isolation of human embryonal carcinoma stem cells by immunomagnetic sorting. 11713341

    Embryonal carcinoma cells are pluripotent stem cells derived from germ cell tumors and can be used to study cell differentiation in vitro. This report describes an approach designed to isolate pluripotent stem cells from primary/parent stock cultures of explanted tumor material. Cells expressing the pluripotent stem cell marker, SSEA-3, were isolated from heterogeneous stock cultures of the human teratoma line, TERA2, using immunomagnetic isolation. Single cell selection was performed on isolated SSEA-3+ cells and clonal lines were established. Each line was ultimately grown as a homogeneous monolayer, independent of feeder cells and expressed high levels of markers for pluripotent stem cells. In response to retinoic acid, clone TERA2.cl.SP-12 cells displayed enhanced neural differentiation compared to previously isolated TERA2 sublines and formed both neurons and glia. Deriving human pluripotent stem cell lines that differentiate into a range of cell types will provide useful tools to understand the molecular mechanisms controlling cell differentiation in a manner pertinent to human embryonic development.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Detection of precytopathic effect of enteroviruses in clinical specimens by centrifugation-enhanced antigen detection. 11473988

    Rapid enterovirus detection is important for decisions about antibiotic administration and length of hospital stay. The efficacy of rapid antigen detection-cell culture amplification (Ag-CCA) was evaluated with monoclonal antibodies (MAbs) 5-D8/1 (DAKO) and Pan-Enterovirus clone 2E11 (Chemicon) with 10 poliovirus, echovirus, and coxsackievirus type A and B stock isolates and College of American Pathologists check samples. By using Ag-CCA technology, MAb 2E11 was more sensitive than 5-D8/1 at detecting a greater number of stock isolates at or past tube (cytopathic effect [CPE]) culture (TC) end points. The efficacy of Ag-CCA in the clinical setting was subsequently confirmed with 273 consecutively freshly collected nasopharyngeal aspirate or swab specimens, rectal swab, and cerebrospinal fluid specimens during the 1999 enterovirus season. All specimens were tested by Ag-CCA in parallel with rhesus monkey kidney (RhMk), MRC-5, and A549 conventional TCs. Approximately 60% of field specimens were additionally tested with Hep-2 and HNK conventional TCs. Sixty-two percent of the clinical specimens tested were Ag-CCA positive after 48 h. Among 51 isolates, the mean time to CPE or culture confirmation was 5.5 days (range, 2 to 18 days). After 48 h, Ag-CCA achieved sensitivity, specificity, and positive and negative predictive values of 62, 100, 100, and 93%, respectively. During the same period, TC-CPE displayed test parameters of 12, 100, 100, and 85%, respectively. After 5 days, the sensitivity and specificity of Ag-CCA increased to 92 and 98%, respectively. Within the same period, isolation attained sensitivity and specificity of 52 and 100%, respectively. Although Ag-CCA displayed slightly reduced sensitivity and reduced specificity compared with conventional cell culture after 14 days, the markedly superior 48-h enterovirus Ag-CCA detection rate supports incorporation of this assay into the routine clinical setting.
    Document Type:
    Reference
    Product Catalog Number:
    3362

  • Effectiveness of reverse transcription-PCR, virus isolation, and enzyme-linked immunosorbent assay for diagnosis of influenza A virus infection in different age groups. 12037063

    The degrees of effectiveness of reverse transcription (RT)-PCR, virus isolation, and antigen enzyme-linked immunosorbent assay (ELISA) for the detection of influenza A virus were evaluated with nasopharyngeal swabs from 150 patients (1 week to 86 years old) with influenza A virus infection. RT-PCR had a sensitivity for influenza A virus in stock virus preparations 10(3) times higher than virus isolation and 10(6) to 10(7) times higher than ELISA. The detection rate achieved by RT-PCR in clinical samples was clearly higher (93%) than that by virus isolation (80%) and ELISA (62%). Despite low overall detection rates achieved by antigen ELISA, samples from patients younger than 5 years old yielded higher-than-average rates in this rapid assay (88%). The likelihood of negative results in the ELISA increased significantly with increasing age of the patient (P 0.01). The degrees of effectiveness of RT-PCR and virus isolation were not influenced by the age of the patient. Neither influenza immunizations nor the interval between onset of symptoms and laboratory investigation (mean, 4.7 days; standard deviation, 3.3 days) affected results obtained by the three test systems. Our results demonstrate that the ELISA is reliable for rapid laboratory diagnosis of influenza in infants and young children, but for older patients application of RT-PCR or virus isolation is necessary to avoid false negative results.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple

  • Lysis of leukemic cells by human macrophages: inhibition by 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), a serine protease inhibitor. 8830789

    Proteases are known to be involved in regulation of macrophage activation and killing. We examined the effect of a serine protease inhibitor, 4-(2-aminoethyl)-benzenesulfonyl fluoride (AEBSF), on lysis of leukemic cells by human macrophages. Monocytes, isolated by Histopaque gradients and centrifugal elutriation, were cultured for 5 days in RPMI-1640 medium with 5% AB serum, and then activated with interferon-gamma (IFN-gamma; 100 U/mL) and lipopolysaccharide (LPS) (5 ng/mL), with or without AEBSF, for 2 days. On day 7, macrophages were washed, fresh medium without AEBSF added, and target cells added for 2 days. Lytic activity against two leukemic cell lines (K562 and HL-60) was assessed by an 111indium-releasing assay. Macrophages treated with IFN-gamma + LPS lysed K562 and HL-60 cells. AEBSF (50-150 microM) blocked the killing of these leukemic cells in a concentration-dependent manner. Other protease inhibitors were not effective. AEBSF was nontoxic at the concentrations used, and did not inhibit tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) secretion from the macrophages. The lytic activity against leukemic cells was inhibited by anti-TNF-alpha antibody, but not by anti-IL-1 beta, nor by superoxide dismutase or catalase. However, the leukemic cells were resistant to being killed by recombinant TNF-alpha alone in the absence of macrophages, indicating that TNF-alpha was required for killing, but that other factors that were inhibited by AEBSF were also required. Serum-free culture supernatant of activated macrophages had significant cytotoxic activity against leukemic cells. This cytotoxic activity was not altered by addition of AEBSF to the culture supernatant, suggesting that AEBSF affected macrophage activation, rather than inhibiting cytotoxic proteases secreted by the macrophages, or affecting the target cells themselves. Thus, a protease, which is susceptible to AEBSF, might be involved in the activation of macrophages, and might regulate the secretion of antitumor effector molecules other than TNF-alpha.
    Document Type:
    Reference
    Product Catalog Number:
    20-176
    Product Catalog Name:
    100X GTPγS, 10mM

  • MDM2-dependent inhibition of p53 is required for Epstein-Barr virus B-cell growth transformation and infected-cell survival. 19144715

    Epstein-Barr virus (EBV) growth transformation of primary B lymphocytes into indefinitely proliferating lymphoblastoid cell lines (LCLs) depends on the concerted activities of a subset of viral proteins expressed during latency. EBV drives quiescent B cells into S phase, and consequently, a host response is activated that includes expression of p53 and its target genes. Since LCLs retain wild-type p53, it was of interest to determine what contribution the p53 pathway may have in controlling established LCL growth and EBV-mediated transformation of primary B cells. We found that liberation of p53 through chemical antagonism of one of its major ubiquitin ligases, MDM2, using the small-molecule Nutlin-3 led to apoptosis of established LCLs and suppressed EBV-mediated transformation of primary B cells. The activation of latent p53 induced target genes associated with apoptosis. Furthermore, MDM2 antagonism synergized with NF-kappaB inhibition in killing LCLs. NF-kappaB was important to increase steady-state MDM2 protein levels rather than in affecting p53-dependent transcription, suggesting a unique mechanism by which LCLs survive in the presence of a primed p53 pathway. Nutlin sensitivity of EBV-infected cells provides a novel system for studying the pathways that dictate LCL survival and regulate EBV transformation. Finally, MDM2 antagonists may be considered for therapeutic intervention in EBV-associated malignancies expressing wild-type p53.
    Document Type:
    Reference
    Product Catalog Number:
    05-100

  • A stereological study of the numbers of neurons and glia in the primary visual cortex across the lifespan of male and female rhesus monkeys. 22430145

    Mild age-related declines in visual function occur in humans and monkeys, independent of ocular pathology, suggesting involvement of central visual pathways (Spear [1993] Vision Res 33:2589-2609). Although many factors might account for this decline, a loss of neurons in primary visual cortex (V1) could be a contributing factor. Previous studies of neuron numbers in V1 reported stability across age, but were limited in the ages and genders studied and sampled only limited parts of V1 or limited cell types, allowing for the possibility of a subtle loss of neurons. We pursued this question in 26 behaviorally tested adult male and female rhesus monkeys ranging from 7.4 to 31.0 years of age by using design-based stereology to estimate numbers of NeuN-labeled neurons and thionin-stained glia within three laminar zones, supragranular (layers II-IVB), granular (IVC), and infragranular (V-VI), across the entirety of V1. There were no significant differences between males and females on any measures, except for total brain weight (P = 0.0038). There was an average of 416,000,000 neurons in V1, but no effect of age on this total or numbers within any laminar zone. Similarly, there was an average of 184,000,000 glia in V1 (44% of the number of neurons), but no effect of age on this total. However, there was a significant age-related increase in numbers of glia in the infragranular zone, perhaps reflecting a glial response to pathology in myelinated projection fibers. This study provides further evidence that in normal aging neurons are not lost and hence cannot account for age-related dysfunction. J. Comp. Neurol. 520:3492-3508, 2012. © 2012 Wiley Periodicals, Inc.
    Document Type:
    Reference
    Product Catalog Number:
    MAB377
    Product Catalog Name:
    Anti-NeuN Antibody, clone A60