Searching the Resource Information Network

Our searching services are busy right now. Please try again later

  • Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

This service exclusively searches for literature that cites resources. Please be aware that the total number of searchable documents is limited to those containing RRIDs and does not include all open-access literature.

Search

Type in a keyword to search

On page 72 showing 1421 ~ 1440 papers out of 56,254 papers

Fluorescence competition assay for the assessment of green leaf volatiles and trans-β-farnesene bound to three odorant-binding proteins in the wheat aphid Sitobion avenae (Fabricius).

  • Tao Zhong‎ et al.
  • Journal of insect physiology‎
  • 2012‎

Odorant-binding proteins (OBPs) are important parts of insect olfactory systems, and sensitive olfaction is vital for phytophagous insects in host foraging. Electrophysiological studies are helpful in understanding olfactory sensing in Sitobion avenae (Hemiptera: Aphididae), but the functions of odorant-binding proteins in this insect are poorly understood. In this study, we used fluorescence competition assays to measure the binding specificities of SaveOBPs. The results showed that both SaveOBP2 and SaveOBP3 were superior to SaveOBP7 in binding green leaf volatiles. It was unexpected that SaveOBP7 bound trans-β-farnesene strongly, which was known as alarm pheromone of this species. Host volatiles were recognized much more easily by SaveOBP2, and the observed binding activity of SaveOBP2 equaled for tested green leaf volatiles. Our results imply that SaveOBP7 might play a more important role in aphid alarm pheromone discrimination.


Identification of Rhit as a novel transcriptional repressor of human Mpv17-like protein with a mitigating effect on mitochondrial dysfunction, and its transcriptional regulation by FOXD3 and GABP.

  • Reiko Iida‎ et al.
  • Free radical biology & medicine‎
  • 2012‎

Mpv17-like protein (M-LP) is a protein that has been suggested to be involved in the metabolism of reactive oxygen species. To elucidate the molecular basis of M-LP expression, we recently searched for regulatory elements of M-LP and identified a novel mouse KRAB-containing protein, Rhit (regulator of heat-induced transcription), as a repressor of the transcriptional regulation of M-LP. In this study, we identified zinc-finger protein 205 as a candidate human Rhit (RhitH) and subsequently confirmed its participation in transcriptional regulation of human M-LP (M-LPH). To clarify the functions of RhitH and M-LPH, we searched for cis-regulatory elements in the promoter region of RhitH and identified two transcription factors: forkhead box D3, as a negative regulatory element, and GA-binding protein, one of the key regulators of the mitochondrial electron transport system, as a positive regulatory element. Additionally, it was demonstrated that knockdown of RhitH or overexpression of M-LPH reduces the generation of intracellular H(2)O(2) and loss of mitochondrial membrane potential caused by an inhibitor of the respiratory chain, antimycin A. These results suggest that M-LPH functions to protect cells from oxidative stress and/or initiation of the mitochondrial apoptotic cascade under stressed conditions.


Expression of retinoid X receptor β is induced in astrocytes during corpus callosum demyelination.

  • René König‎ et al.
  • Journal of chemical neuroanatomy‎
  • 2012‎

The experimental activation of retinoid receptors reduces pathological symptoms in animal models of multiple sclerosis. In order to assess the involvement of endogenous retinoid signaling during the process of demyelination we investigated retinoic acid synthesizing enzymes and nuclear receptors using the mouse model of cuprizone toxicity. The initiation of myelin degradation in the corpus callosum was accompanied with a local increase of retinaldehyde dehydrogenase (RALDH) immunoreactivity. On the level of receptors we observed a striking increase in protein expression of the retinoid X receptor (RXR)-β in the affected corpus callosum. The RXRβ immunoreactivity appeared exclusively in astrocytes, where it reached a maximum at five weeks of treatment, following the RALDH response. In the cerebral cortex and basal ganglia of affected mice RXRβ was also observed in neurons. Among nuclear receptor antigens RARα showed a cuprizone associated increase in the corpus callosum. Quantitative RT-PCR revealed strong basal expression of RXRβ and a significant, over 20-fold upregulation of the peroxisome proliferator-activated receptor-γ during demyelination. The results indicate that compensatory mechanisms during central demyelination may engage nuclear receptor dimers with an RXRβ partner.


Genetic variation in TRPS1 may regulate hip geometry as well as bone mineral density.

  • Cheryl L Ackert-Bicknell‎ et al.
  • Bone‎
  • 2012‎

Trps1 has been proposed as a candidate gene for a mouse bone mineral density (BMD) QTL on Chromosome (Chr) 15, but it remained unclear if this gene was associated with BMD in humans. We used newly available data and advanced bioinformatics techniques to confirm that Trps1 is the most likely candidate gene for the mouse QTL. In short, by combining the raw genetic mapping data from two F2 generation crosses of inbred strains of mice, we narrowed the 95% confidence interval of this QTL down to the Chr 15 region spanning from 6 to 24cM. This region contains 131 annotated genes. Using block haplotyping, all other genes except Trps1 were eliminated as candidates for this QTL. We then examined associations of 208 SNPs within 10kb of TRPS1 with BMD and hip geometry, using human genome-wide association study (GWAS) data from the GEFOS consortium. After correction for multiple testing, six TRPS1 SNPs were significantly associated with femoral neck BMD (P=0.0015-0.0019; adjusted P=0.038-0.048). We also found that three SNPs were highly associated with femoral neck width in women (rs10505257, P=8.6×10(-5), adjusted P=2.15×10(-3); rs7002384, P=5.5×10(-4), adjusted P=01.38×10(-2)). In conclusion, we demonstrated that combining association studies in humans with murine models provides an efficient strategy to identify new candidate genes for bone phenotypes.


Modulation of the interaction between neurotensin receptor NTS1 and Gq protein by lipid.

  • Sayaka Inagaki‎ et al.
  • Journal of molecular biology‎
  • 2012‎

Membrane lipids have been implicated to influence the activity of G-protein-coupled receptors (GPCRs). Almost all of our knowledge on the role of lipids on GPCR and G protein function comes from work on the visual pigment rhodopsin and its G protein transducin, which reside in a highly specialized membrane environment. Thus, insight gained from rhodopsin signaling may not be simply translated to other nonvisual GPCRs. Here, we investigated the effect of lipid head group charges on the signal transduction properties of the class A GPCR neurotensin (NT) receptor 1 (NTS1) under defined experimental conditions, using self-assembled phospholipid nanodiscs prepared with the zwitter-ionic lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), the negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG), or a POPC/POPG mixture. A combination of dynamic light scattering and sedimentation velocity showed that NTS1 was monomeric in POPC-, POPC/POPG-, and POPG-nanodiscs. Binding of the agonist NT to NTS1 occurred with similar affinities and was essentially unaffected by the phospholipid composition. In contrast, Gq protein coupling to NTS1 in various lipid nanodiscs was significantly different, and the apparent affinity of Gαq and Gβ(1)γ(1) to activated NTS1 increased with increasing POPG content. NTS1-catalyzed GDP/GTPγS nucleotide exchange at Gαq in the presence of Gβ(1)γ(1) and NT was crucially affected by the lipid type, with exchange rates higher by 1 or 2 orders of magnitude in POPC/POPG- and POPG-nanodiscs, respectively, compared to POPC-nanodiscs. Our data demonstrate that negatively charged lipids in the immediate vicinity of a nonvisual GPCR modulate the G-protein-coupling step.


Chimeric calicivirus-like particles elicit specific immune responses in pigs.

  • E Crisci‎ et al.
  • Vaccine‎
  • 2012‎

Virus-like particles (VLPs) have received considerable attention due to their potential application in veterinary vaccines and, in particular, VLPs from rabbit haemorrhagic disease virus (RHDV) have successfully shown to be good platforms for inducing immune responses against an inserted foreign epitope in mice. The aim of this study was to assess the immunogenicity of chimeric RHDV-VLPs as vaccine vectors in pigs. For this purpose, we have generated chimeric VLPs containing a well-known T epitope of 3A protein of foot-and-mouth disease virus (FMDV). Firstly, RHDV-VLPs were able to activate immature porcine bone marrow-derived dendritic cells (poBMDCs) in vitro. Secondly, pigs were inoculated twice in a two-week interval with chimeric RHDV-VLPs at different doses intranasally or intramuscularly. One intramuscularly treated group was also inoculated with adjuvant Montanide™ ISA 206 at the same time. Specific IgG and IgA antibodies against RHDV-VLPs were induced and such levels were higher in the adjuvanted group compared with other groups. Interestingly, anti-RHDV-VLP IgA responses were higher in groups inoculated intramuscularly than those that received the VLPs intranasally. Two weeks after the last immunisation, specific IFN-γ-secreting cells against 3A epitope and against RHDV-VLPs were detected in PBMCs by ELISPOT. The adjuvanted group exhibited the highest IFN-γ-secreting cell numbers and lymphoproliferative specific T cell responses against 3A epitope and RHDV-VLP. This is the first immunological report on the potential use of chimeric RHDV-VLPs as antigen carriers in pigs.


Measuring longitudinal change in the hippocampal formation from in vivo high-resolution T2-weighted MRI.

  • Sandhitsu R Das‎ et al.
  • NeuroImage‎
  • 2012‎

The hippocampal formation (HF) is a brain structure of great interest because of its central role in learning and memory, and its associated vulnerability to several neurological disorders. In vivo oblique coronal T2-weighted MRI with high in-plane resolution (~0.5 mm × 0.5 mm), thick slices (~2.0 mm), and a field of view tailored to imaging the hippocampal formation (denoted HF-MRI in this paper) has been advanced as a useful imaging modality for detailed hippocampal morphometry. Cross-sectional analysis of volume measurements derived from HF-MRI has shown the modality's promise to yield sensitive imaging-based biomarker for neurological disorders such as Alzheimer's disease. However, the utility of this modality for making measurements of longitudinal change has not yet been demonstrated. In this paper, using an unbiased deformation-based morphometry (DBM) pipeline, we examine the suitability of HF-MRI for estimating longitudinal change by comparing atrophy rates measured in the whole hippocampus from this modality with those measured from more common isotropic (~1 mm³) T1-weighted MRI in the same set of individuals, in a cohort of healthy controls and patients with cognitive impairment. While measurements obtained from HF-MRI were largely consistent with those obtained from T1-MRI, HF-MRI yielded slightly larger group effect of greater atrophy rates in patients than in controls. The estimated minimum sample size required for detecting a 25% change in patients' atrophy rate in the hippocampus compared to the control group with a statistical power β=0.8 was N=269. For T1-MRI, the equivalent sample size was N=325. Using a dataset of test-retest scans, we show that the measurements were free of additive bias. We also demonstrate that these results were not a confound of certain methodological choices made in the DBM pipeline to address the challenges of making longitudinal measurements from HF-MRI, using a region of interest (ROI) around the HF to globally align serial images, followed by slice-by-slice deformable registration to measure local volume change. Additionally, we present a preliminary study of atrophy rate measurements within hippocampal subfields using HF-MRI. Cross-sectional differences in atrophy rates were detected in several subfields.


Brain 'talks over' boring quotes: top-down activation of voice-selective areas while listening to monotonous direct speech quotations.

  • Bo Yao‎ et al.
  • NeuroImage‎
  • 2012‎

In human communication, direct speech (e.g., Mary said, "I'm hungry") is perceived as more vivid than indirect speech (e.g., Mary said that she was hungry). This vividness distinction has previously been found to underlie silent reading of quotations: Using functional magnetic resonance imaging (fMRI), we found that direct speech elicited higher brain activity in the temporal voice areas (TVA) of the auditory cortex than indirect speech, consistent with an "inner voice" experience in reading direct speech. Here we show that listening to monotonously spoken direct versus indirect speech quotations also engenders differential TVA activity. This suggests that individuals engage in top-down simulations or imagery of enriched supra-segmental acoustic representations while listening to monotonous direct speech. The findings shed new light on the acoustic nature of the "inner voice" in understanding direct speech.


Near and far space neglect: task sensitivity and anatomical substrates.

  • Lina Aimola‎ et al.
  • Neuropsychologia‎
  • 2012‎

Most group studies which have investigated neglect for near and far space have found an increased severity of symptoms in far space compared to near space. However, the majority of these studies used relatively small samples and based their findings almost exclusively on line bisection performance. The aim of the present study was, therefore, to explore the occurrence of neglect for near and far space in a larger group of unselected right brain damaged patients and to evaluate whether neglect specific to near and far space is a task-related deficit or generalises across distance irrespective of task. In addition, a lesion overlap analysis was carried out to identify critical lesion sites associated with distance specific neglect deficits. Thirty-eight right hemisphere damaged patients carried out a line bisection and a cancellation task by using a pen in near space (40 cm) and a laser pointer in far space (320 cm). The results showed that both the number of left-sided omissions and rightward bisection errors were significantly increased in near compared to far space. Distance specific dissociations, albeit less common, were more frequently observed for cancellation than line bisection. These results suggest that space representation in neglect is more severely impaired in near than in far space. In addition, distance related dissociations in neglect may depend on task demands. Although the anatomical findings were broadly consistent with a dorsal and ventral stream dichotomy for near and far space processing, they also suggest the involvement of intermediate structures in distance related neglect phenomena.


Alterations of the amplitude of low-frequency fluctuations in treatment-resistant and treatment-response depression: a resting-state fMRI study.

  • Wen-bin Guo‎ et al.
  • Progress in neuro-psychopharmacology & biological psychiatry‎
  • 2012‎

Patients with treatment-resistant depression (TRD) and those with treatment-response depression (TSD) respond to antidepressants differently and previous studies have commonly reported different brain networks in resistant and nonresistant patients. Using the amplitude of low-frequency fluctuations (ALFF) approach, we explored ALFF values of the brain regions in TRD and TSD patients at resting state to test the hypothesis of the different brain networks in TRD and TSD patients.


The association between fat and lean mass and bone mineral density: the Healthy Twin Study.

  • Joo-Hyun Park‎ et al.
  • Bone‎
  • 2012‎

The potential beneficial effects of increased body weight on bone mineral density (BMD) conflict with the adverse effects of obesity on various health outcomes, necessitating more specific evaluations of the association between each body component and BMD. In the present study, we evaluated associations of lean mass (LM) and fat mass (FM) with BMD in a Korean sample consisting of a total of 1782 men and women whose mean (standard deviation) age was 43.2 (12.6) years. They were selected from the Healthy Twin Study, a nationwide Korean twin and family study. BMD, FM and LM were measured using dual-energy X-ray absorptiometry. Quantitative genetic analysis and linear mixed analysis were performed with respect to familial relationships and a wide range of probable covariates. Linear mixed analysis revealed that BMD was positively associated with both FM and LM at each region of BMD measurement (whole body, spine, arms, and legs) in men, premenopausal women, and postmenopausal women. However, the association with BMD was stronger for LM than FM. Both LM and FM had positive genetic correlations with BMD at each region, although the correlation with BMD tended to be stronger for LM than FM. Together, these findings suggest that increased LM, rather than FM, is more beneficial for BMD in the Korean population and warrants further study of the common genetic determinants of BMD and body composition.


Rapid identification of monospecific monoclonal antibodies using a human proteome microarray.

  • Jun Seop Jeong‎ et al.
  • Molecular & cellular proteomics : MCP‎
  • 2012‎

To broaden the range of tools available for proteomic research, we generated a library of 16,368 unique full-length human ORFs that are expressible as N-terminal GST-His(6) fusion proteins. Following expression in yeast, these proteins were then individually purified and used to construct a human proteome microarray. To demonstrate the usefulness of this reagent, we developed a streamlined strategy for the production of monospecific monoclonal antibodies that used immunization with live human cells and microarray-based analysis of antibody specificity as its central components. We showed that microarray-based analysis of antibody specificity can be performed efficiently using a two-dimensional pooling strategy. We also demonstrated that our immunization and selection strategies result in a large fraction of monospecific monoclonal antibodies that are both immunoblot and immunoprecipitation grade. Our data indicate that the pipeline provides a robust platform for the generation of monoclonal antibodies of exceptional specificity.


Coordination of multiple enzyme activities by a single PCNA in archaeal Okazaki fragment maturation.

  • Thomas R Beattie‎ et al.
  • The EMBO journal‎
  • 2012‎

Chromosomal DNA replication requires one daughter strand-the lagging strand-to be synthesised as a series of discontinuous, RNA-primed Okazaki fragments, which must subsequently be matured into a single covalent DNA strand. Here, we describe the reconstitution of Okazaki fragment maturation in vitro using proteins derived from the archaeon Sulfolobus solfataricus. Six proteins are necessary and sufficient for coupled DNA synthesis, RNA primer removal and DNA ligation. PolB1, Fen1 and Lig1 provide the required catalytic activities, with coordination of their activities dependent upon the DNA sliding clamp, proliferating cell nuclear antigen (PCNA). S. solfataricus PCNA is a heterotrimer, with each subunit having a distinct specificity for binding PolB1, Fen1 or Lig1. Our data demonstrate that the most efficient coupling of activities occurs when a single PCNA ring organises PolB1, Fen1 and Lig1 into a complex.


A cross-sectional study of glucose regulation in young adults with very low birth weight: impact of male gender on hyperglycaemia.

  • Ryosuke Sato‎ et al.
  • BMJ open‎
  • 2012‎

To investigate glucose regulation in young adults with very low birth weight (VLBW; <1500 g) in an Asian population.


Mouse forestomach carcinoma cells immunosuppress macrophages through transforming growth factor-β1.

  • Huaxing Luo‎ et al.
  • Molecular medicine reports‎
  • 2012‎

Peritoneal implantation metastasis of gastric cancer cells is associated with poor prognosis. Peritoneal macrophages are the most important immune cells in the abdominal cavity to control tumor metastasis. In the present study, the immunosuppressive effects of mouse forestomach cells on macrophages were examined. Conditioned medium from mouse forestomach cell cultures were used to treat isolated peritoneal macrophages. A colorimetry-based phagocytosis assay was performed to investigate the functional change of macrophages. The alteration of cytokine secretion by macrophages was measured by ELISA assay. Specific markers of macrophage polarization were analyzed by real-time RT-PCR. TGF-β1 signaling was evaluated by western blotting. Neutralization experiments were performed using an anti-TGF-β1 antibody. Conditioned medium reduced the phagocytotic capability of macrophages. Lower TNF-α and IL-1β levels and higher IL-10 and VEGF levels were observed. Real-time RT-PCR showed increased mRNA levels of M2 macrophage markers. Further study revealed that TGF-β1 was significantly elevated in the conditioned medium and TGF-β1 signaling was activated in the macrophages by the treatment of conditioned medium. Neutralization of TGF-β1 reversed the immunosuppressive effects on macrophages. Immunosuppressive macrophages can be induced by conditioned medium from mouse forestomach cell cultures. These effects appeared to occur through the production of TGF-β1 by the tumor cells. Targeted TGF-β1 intervention may help to control peritoneal metastasis of gastric cancers.


Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells.

  • Yuan-Yuan Hua‎ et al.
  • Molecular medicine reports‎
  • 2012‎

The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway.


Class III PI3K Vps34 plays an essential role in autophagy and in heart and liver function.

  • Nadia Jaber‎ et al.
  • Proceedings of the National Academy of Sciences of the United States of America‎
  • 2012‎

A critical regulator of autophagy is the Class III PI3K Vps34 (also called PIK3C3). Although Vps34 is known to play an essential role in autophagy in yeast, its role in mammals remains elusive. To elucidate the physiological function of Vps34 and to determine its precise role in autophagy, we have generated Vps34(f/f) mice, in which expression of Cre recombinase results in a deletion of exon 4 of Vps34 and a frame shift causing a deletion of 755 of the 887 amino acids of Vps34. Acute ablation of Vps34 in MEFs upon adenoviral Cre infection results in a diminishment of localized generation of phosphatidylinositol 3-phosphate and blockade of both endocytic and autophagic degradation. Starvation-induced autophagosome formation is blocked in both Vps34-null MEFs and liver. Liver-specific Albumin-Cre;Vps34(f/f) mice developed hepatomegaly and hepatic steatosis, and impaired protein turnover. Ablation of Vps34 in the heart of muscle creatine kinase-Cre;Vps34(f/f) mice led to cardiomegaly and decreased contractility. In addition, while amino acid-stimulated mTOR activation was suppressed in the absence of Vps34, the steady-state level of mTOR signaling was not affected in Vps34-null MEFs, liver, or cardiomyocytes. Taken together, our results indicate that Vps34 plays an essential role in regulating functional autophagy and is indispensable for normal liver and heart function.


Arthroscopic, histological and MRI analyses of cartilage repair after a minimally invasive method of transplantation of allogeneic synovial mesenchymal stromal cells into cartilage defects in pigs.

  • Tomomasa Nakamura‎ et al.
  • Cytotherapy‎
  • 2012‎

Transplantation of synovial mesenchymal stromal cells (MSCs) may induce repair of cartilage defects. We transplanted synovial MSCs into cartilage defects using a simple method and investigated its usefulness and repair process in a pig model.


Prostaglandin E2 contributes to the synthesis of brain-derived neurotrophic factor in primary sensory neuron in ganglion explant cultures and in a neuropathic pain model.

  • Pedro Cruz Duarte‎ et al.
  • Experimental neurology‎
  • 2012‎

Brain-derived neurotrophic factor (BDNF) exists in small to medium size neurons in adult rat dorsal root ganglion (DRG) and serves as a modulator at the first synapse of the pain transmission pathway in the spinal dorsal horn. Peripheral nerve injury increases BDNF expression in DRG neurons, an event involved in the genesis of neuropathic pain. In the present study, we tested the hypothesis that prostaglandin E2 (PGE2) over-produced in injured nerves contributes to the up-regulation of BDNF in DRG neurons. Two weeks after partial sciatic nerve ligation (PSNL), BDNF levels in the ipsilateral L4-L6 DRG of injured rats were significantly increased compared to the contralateral side. Perineural injection of a selective cyclooxygenase (COX2) inhibitor or a PGE2 EP4 receptor antagonist not only dose-dependently relieved PSNL elicited mechanical hypersensitivity, but also suppressed the increased BDNF levels in DRG neurons. PSNL shifted BDNF expression in the ipsilateral DRG from small to medium and larger size injured neurons. BDNF is mainly co-expressed with the EP1 and EP4 while moderately with the EP2 and EP3 receptor subtypes in naïve and PSNL rats. PSNL also shifted the expression of EP1-4 receptors to a larger size population of DRG neurons. In DRG explant cultures, a stabilized PGE2 analog 16,16 dimethyl PGE2 (dmPGE2) or the agonists of EP1 and EP4 receptors significantly increased BDNF levels and the phosphorylated protein kinase A (PKA), extracellular signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) and cAMP response element binding protein (CREB). The EP1 and EP4 antagonists, a sequester of nerve growth factor (NGF), the inhibitors of PKA and MEK as well as CREB small interfering RNA suppressed dmPGE2-induced BDNF. Taken together, EP1 and EP4 receptor subtypes, PKA, ERK/MAPK and CREB signaling pathways as well as NGF are involved in PGE2-induced BDNF synthesis in DRG neurons. Injured nerve derived-PGE2 contributes to BDNF up-regulation in DRG neurons following nerve injury. Facilitating the synthesis of BDNF in primary sensory neurons is a novel mechanism underlying the role of PGE2 in the genesis of neuropathic pain.


A new flow-cytometry-based opsonophagocytosis assay for the rapid measurement of functional antibody levels against Group B Streptococcus.

  • Monica Fabbrini‎ et al.
  • Journal of immunological methods‎
  • 2012‎

Opsonophagocytosis is the primary mechanism for the clearance of Group B Streptococcus (GBS) by the host, and levels of opsonic antibodies may correlate with protection in preclinical models. A killing-based opsonophagocytosis assay (OPA), can be used to determine the functional activity of vaccine-induced GBS-specific antibodies. The assay, which measures the number of bacterial colonies surviving phagocytic killing in the presence of specific antibodies and complement, is rather expensive, time-consuming and poorly standardized. Here we describe a rapid, sensitive and reproducible fluorescent OPA assay (fOPA) based on flow cytometry analysis (FACS), which allows internalized bacteria to be distinguished from those associated to the plasma membrane of phagocytic cells. Fixed GBS were labeled with pHrodo™, a fluorescent dye which dramatically increases the emitted fluorescence at the acidic conditions present in the phagocytic endosomal compartment. Labeled bacteria were incubated with HL-60 cells differentiated to phagocytes, antibodies and complement, and then analyzed by FACS. A further improvement to our method, allowing to reduce assay variability, consisted on a step of selection of effector cells among the HL-60 population. Analysis of sera from mice immunized with different GBS vaccines revealed comparable sensitivity and specificity with the traditional killing OPA assay (kOPA), and a good correlation between the fluorescent signal of bacteria internalized by HL-60 phagocytes and killing. Remarkably, the pHrodo-based approach reduced the variability observed with other fOPA assays. The obtained data indicate the proposed fOPA as a reliable and useful tool for functional antibody assessment.


  1. PRECISE-TBI Resources

    Welcome to the PRECISE-TBI Resources search. From here you can search through a compilation of resources used by PRECISE-TBI and see how data is organized within our community.

  2. Navigation

    You are currently on the Community Resources tab looking through categories and sources that PRECISE-TBI has compiled. You can navigate through those categories from here or change to a different tab to execute your search through. Each tab gives a different perspective on data.

  3. Logging in and Registering

    If you have an account on PRECISE-TBI then you can log in from here to get additional features in PRECISE-TBI such as Collections, Saved Searches, and managing Resources.

  4. Searching

    Here is the search term that is being executed, you can type in anything you want to search for. Some tips to help searching:

    1. Use quotes around phrases you want to match exactly
    2. You can manually AND and OR terms to change how we search between words
    3. You can add "-" to terms to make sure no results return with that term in them (ex. Cerebellum -CA1)
    4. You can add "+" to terms to require they be in the data
    5. Using autocomplete specifies which branch of our semantics you with to search and can help refine your search
  5. Save Your Search

    You can save any searches you perform for quick access to later from here.

  6. Query Expansion

    We recognized your search term and included synonyms and inferred terms along side your term to help get the data you are looking for.

  7. Collections

    If you are logged into PRECISE-TBI you can add data records to your collections to create custom spreadsheets across multiple sources of data.

  8. Facets

    Here are the facets that you can filter your papers by.

  9. Options

    From here we'll present any options for the literature, such as exporting your current results.

  10. Further Questions

    If you have any further questions please check out our FAQs Page to ask questions and see our tutorials. Click this button to view this tutorial again.

Publications Per Year

X

Year:

Count: