999 research outputs found

    How-to: Undergraduate Research

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    The Impact of Epidural Steroid Injections on the Outcomes of Patients Treated for Lumbar Disc Herniation: A Subgroup Analysis of the SPORT Trial.

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    BACKGROUND: The Spine Patient Outcomes Research Trial (SPORT) is a prospective, multicenter study of operative versus nonoperative treatment of lumbar intervertebral disc herniation. It has been suggested that epidural steroid injections may help improve patient outcomes and lower the rate of crossover to surgical treatment. METHODS: One hundred and fifty-four patients included in the intervertebral disc herniation arm of the SPORT who had received an epidural steroid injection during the first three months of the study and no injection prior to the study (the ESI group) were compared with 453 patients who had not received an injection during the first three months of the study or prior to the study (the No-ESI group). RESULTS: There was a significant difference in the preference for surgery between groups (19% in the ESI group compared with 56% in the No-ESI group, p \u3c 0.001). There was no difference in primary or secondary outcome measures at four years between the groups. A higher percentage of patients changed from surgical to nonsurgical treatment in the ESI group (41% versus 12% in the No-ESI, p \u3c 0.001). CONCLUSIONS: Patients with lumbar disc herniation treated with epidural steroid injection had no improvement in short or long-term outcomes compared with patients who were not treated with epidural steroid injection. There was a higher prevalence of crossover to nonsurgical treatment among surgically assigned ESI-group patients, although this was confounded by the increased baseline desire to avoid surgery among patients in the ESI group. Given these data, we concluded that more studies are necessary to establish the value of epidural steroid injection for symptomatic lumbar intervertebral disc herniation. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence

    The Pseudophosphatase MK-STYX Induces Neurite-Like Outgrowths in PC12 Cells

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    The rat pheochromocytoma PC12 cell line is a widely used system to study neuronal differentiation for which sustained activation of the extracellular signaling related kinase (ERK) pathway is required. Here, we investigate the function of MK-STYX [MAPK (mitogen-activated protein kinase) phosphoserine/threonine/tyrosine-binding protein] in neuronal differentiation. MK-STYX is a member of the MAPK phosphatase (MKP) family, which is generally responsible for dephosphorylating the ERKs. However, MK-STYX lacks catalytic activity due to the absence of the nucleophilic cysteine in the active site signature motif HC(X-5)R that is essential for phosphatase activity. Despite being catalytically inactive, MK-STYX has been shown to play a role in important cellular pathways, including stress responses. Here we show that PC12 cells endogenously express MK-STYX. In addition, MK-STYX, but not its catalytically active mutant, induced neurite-like outgrowths in PC12 cells. Furthermore, MK-STYX dramatically increased the number of cells with neurite extensions in response to nerve growth factor (NGF), whereas the catalytically active mutant did not. MK-STYX continued to induce neurites in the presence of a MEK (MAP kinase kinase) inhibitor suggesting that MK-STYX does not act through the Ras-ERK/MAPK pathway but is involved in another pathway whose inactivation leads to neuronal differentiation. RhoA activity assays indicated that MK-STYX induced extensions through the Rho signaling pathway. MK-STYX decreased RhoA activation, whereas RhoA activation increased when MK-STYX was down-regulated. Furthermore, MK-STYX affected downstream players of RhoA such as the actin binding protein cofilin. The presence of MK-STYX decreased the phosphorylation of cofilin in non NGF stimulated cells, but increased its phosphorylation in NGF stimulated cells, whereas knocking down MK-STYX caused an opposite effect. Taken together our data suggest that MK-STYX may be a regulator of RhoA signaling, and implicate this pseudophosphatase as a regulator of neuronal differentiation

    Relationship between Length and Surface-Enhanced Raman Spectroscopy Signal Strength in Metal Nanoparticle Chains: Ideal Models versus Nanofabrication

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    We have employed capillary force deposition on ion beam patterned substrates to fabricate chains of 60 nm gold nanospheres ranging in length from 1 to 9 nanoparticles. Measurements of the surface-averaged SERS enhancement factor strength for these chains were then compared to the numerical predictions. The SERS enhancement conformed to theoretical predictions in the case of only a few chains, with the vast majority of chains tested not matching such behavior. Although all of the nanoparticle chains appear identical under electron microscope observation, the extreme sensitivity of the SERS enhancement to nanoscale morphology renders current nanofabrication methods insufficient for consistent production of coupled nanoparticle chains. Notwithstanding this fact, the aggregate data also confirmed that nanoparticle dimers offer a large improvement over the monomer enhancement while conclusively showing that, within the limitations imposed by current state-of-the-art nanofabrication techniques, chains comprising more than two nanoparticles provide only a marginal signal boost over the already considerable dimer enhancement

    Sixty years of Sverdrup : a retrospective of progress in the study of phytoplankton blooms

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    Author Posting. © The Oceanography Society, 2014. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 27, no. 1 (2014): 222–235, doi:10.5670/oceanog.2014.26.One of the most dramatic large-scale features in the ocean is the seasonal greening of the North Atlantic in spring and summer due to the accumulation of phytoplankton biomass in the surface layer. In 1953, Harald Ulrik Sverdrup hypothesized a now canonical mechanism for the development and timing of phytoplankton blooms in the North Atlantic. Over the next 60 years, Sverdrup's Critical Depth Hypothesis spurred progress in understanding of bloom dynamics and offered a valuable theoretical framework on which to build. In reviewing 60 years of literature, the authors trace the development of modern bloom initiation hypotheses, highlighting three case studies that illuminate the complexity, including both catalysts and impediments, of scientific progress in the wake of Sverdrup's hypothesis. Most notably, these cases demonstrate that the evolution of our understanding of phytoplankton blooms was paced by access not only to technology but also to concurrent insights from several disciplines. This exploration of the trajectories and successes in bloom studies highlights the need for expanding interdisciplinary collaborations to address the complexity of phytoplankton bloom dynamics

    “That never happened”: Adults' discernment of children's true and false memory reports.

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    Adults’ evaluations of children’s reports can determine whether legal proceedings are undertaken and whether they ultimately lead to justice. The current study involved 92 undergraduates and 35 laypersons who viewed and evaluated videotaped interviews of 3- and 5-year-olds providing true or false memory reports. The children’s reports fell into the following categories based on a 2 (event type: true vs. false) × 2 (child report: assent vs. denial) factorial design: Accurate reports, false reports, accurate denials, and false denials. Results revealed that adults were generally better able to correctly judge accurate reports, accurate denials, and false reports compared to false denials: For false denials, adults were, on average, “confident” that the event had not occurred, even though the event had in fact been experienced. Participant age predicted performance. These findings underscore the greater difficulty adults have in evaluating young children’s false denials compared to other types of reports. Implications for law-related situations in which adults are called upon to evaluate children’s statements are discussed

    Alterations of immune response of non-small lung cancer with azacytidine

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    Innovative therapies are needed for advanced Non-Small Cell Lung Cancer (NSCLC). We have undertaken a genomics based, hypothesis driving, approach to query an emerging potential that epigenetic therapy may sensitize to immune checkpoint therapy targeting PD-L1/PD-1 interaction. NSCLC cell lines were treated with the DNA hypomethylating agent azacytidine (AZA - Vidaza) and genes and pathways altered were mapped by genome-wide expression and DNA methylation analyses. AZA-induced pathways were analyzed in The Cancer Genome Atlas (TCGA) project by mapping the derived gene signatures in hundreds of lung adeno (LUAD) and squamous cell carcinoma (LUSC) samples. AZA up-regulates genes and pathways related to both innate and adaptive immunity and genes related to immune evasion in a several NSCLC lines. DNA hypermethylation and low expression of IRF7, an interferon transcription factor, tracks with this signature particularly in LUSC. In concert with these events, AZA up-regulates PD-L1 transcripts and protein, a key ligand-mediator of immune tolerance. Analysis of TCGA samples demonstrates that a significant proportion of primary NSCLC have low expression of AZA-induced immune genes, including PD-L1. We hypothesize that epigenetic therapy combined with blockade of immune checkpoints - in particular the PD-1/PD-L1 pathway - may augment response of NSCLC by shifting the balance between immune activation and immune inhibition, particularly in a subset of NSCLC with low expression of these pathways. Our studies define a biomarker strategy for response in a recently initiated trial to examine the potential of epigenetic therapy to sensitize patients with NSCLC to PD-1 immune checkpoint blockade
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