1,095 research outputs found

    Novel expression of Haemonchus contortus vaccine candidate aminopeptidase H11 using the free-living nematode Caenorhabditis elegans

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    With the problem of parasitic nematode drug resistance increasing, vaccine development offers an alternative sustainable control approach. For some parasitic nematodes, native extracts enriched for specific proteins are highly protective. However, recombinant forms of these proteins have failed to replicate this protection. This is thought to be due to differences in glycosylation and/or conformation between native and recombinant proteins. We have exploited the free-living nematode Caenorhabditis elegans to examine its suitability as an alternative system for recombinant expression of parasitic nematode vaccine candidates. We focussed on Haemonchus contortus aminopeptidase H11 glycoprotein, which is enriched in a gut membrane fraction capable of inducing significant protection against this important ovine gastrointestinal nematode. We show that H. contortus H11 expressed in C. elegans is enzymatically active and MALDI mass spectrometry identifies similar di- and tri-fucosylated structures to those on native H11, with fucose at the 3- and/or 6-positions of the proximal GlcNAc. Some glycan structural differences were observed, such as lack of LDNF. Serum antibody to native H11 binds to C. elegans recombinant H11 and most of the antibody to rH11 or native H11 is directed to glycan moieties. Despite these similarities, no reduction in worm burden or faecal egg count was observed following immunisation of sheep with C. elegans-expressed recombinant H11 protein. The findings suggest that the di- and tri-fucosylated N-glycans expressed on rH11 do not contribute to the protective effect of H11 and that additional components present in native H11-enriched extract are likely required for enhancing the antibody response necessary for protection

    Mudanças das práticas discursivas de professores aprendendo matemáticas dinâmicas em um ambiente colaborativo online

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    Using data from an inservice professional development course, we inquire into changes in secondary teachers’ discursive practices in a latter part of the course compared to the beginning of the course. Participants interacted in a collaborative online environment, known as Virtual Math Teams with GeoGebra (VMTwG), focusing on discursive, mathematical, and collaborative practices. From a sociocultural perspective, we believe that teachers gradually develop their Technological Pedagogical Content Knowledge (TPACK) by interacting discursively in small teams. Using conventional content analysis of the teachers’ review of their recorded discourse, we investigate changes in practices from the teachers’ perspective. Our results show that teachers perceived that their discursive practices differed importantly from their practices at the beginning of the course.Usando dados de uma disciplina de desenvolvimento profissional para professores de matemática em serviço, investigamos as mudanças nas práticas discursivas dos professores de Fundamental II e Ensino Médio em uma última parte da disciplina, em comparação com o início da disciplina. Os professores interagiram em um ambiente colaborativo online, conhecido como Virtual Math Teams com GeoGebra (VMTcG), com foco em práticas discursivas, matemáticas e colaborativas. De uma perspectiva sociocultural, acreditamos que os professores desenvolvem gradualmente o seu conhecimento tecnológico, pedagógico e do conteúdo (TPACK), interagindo discursivamente em equipes pequenas. Usando a análise de conteúdo convencional da revisão dos professores sobre seu discurso gravado, investigamos as mudanças nas práticas da perspectiva dos professores. Nossos resultados mostram que os professores perceberam que suas práticas discursivas diferiam importantemente de suas práticas no início do curso

    Toxicity of Phase I Radiation Oncology Trials: Worldwide Experience

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    Introduction: Informed consent involves understanding the risks and benefits of trial enrollment. This is challenging in the phase I setting since true quantitative information is never known. We therefore performed an analysis of published radiation oncology (RO) phase I trials emphasizing patient outcomes. To our knowledge, no such systemic analysis has previously been published. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

    Observations of M87 and Hydra A at 90 GHz

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    This paper presents new observations of the AGNs M87 and Hydra A at 90 GHz made with the MUSTANG bolometer array on the Green Bank Telescope at 8.5" resolution. A spectral analysis is performed combining this new data and archival VLA data on these objects at longer wavelengths. This analysis can detect variations in spectral index and curvature expected from energy losses in the radiating particles. M87 shows only weak evidence for steepening of the spectrum along the jet suggesting either re-acceleration of the relativistic particles in the jet or insufficient losses to affect the spectrum at 90 GHz. The jets in Hydra A show strong steepening as they move from the nucleus suggesting unbalanced losses of the higher energy relativistic particles. The difference between these two sources may be accounted for by the different lengths over which the jets are observable, 2 kpc for M87 and 45 kpc for Hydra A.Comment: 11 pages, submitted to Ap

    Effect of Cediranib, Temozolamide and Radiotherapy in U87 GBM wtEGFR and EGFRvIII-expressing Xenografts

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    Introduction: Glioblastomas (GBM) frequently overexpress the epidermal growth factor receptor (wtEGFR) or its mutant, EGFRvIII contributing to radioresistance. New treatment strategies for GBM include blockade of EGFR signaling and angiogenesis. Cediranib (CD) is a highly potent VEGFR-2 RTKI that inhibits all three VEGF receptors. This study investigated the radiosensitizing potential of CD in combination with temozolamide (TMZ) in U87 GBM xenografts expressing wtEGFR or EGFRvIII. Radiation Research Society (RRS) 8th Annual Meeting September 25-29, Maui, H

    Evolving Role of Vorinostat Combined with Radiation Therapy in the Treatment of Brain Tumors, from the Lab to the Clinic

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    Purpose/Objective(s): Radiation therapy (RT) is a critical element in the treatment of both brain metastases and glioblastoma (GBM). Temozolomide (TMZ) has an established role in the upfront treatment of GBM. Down-regulated mismatch repair (MMR) is a known mechanism of resistance to TMZ. Vorinostat (SAHA), an HDAC inhibitor, has successfully been combined with a number of cytotoxic agents, including ionizing radiation (IR). We performed a series of preclinical and clinical studies to examine the role of SAHA in the treatment of brain tumors. American Society for Therapeutic Radiation Oncology (ASTRO) 52nd Annual Meeting October 31 - November 4, San Diego, C

    Functional Antagonism Between Vorinostat and Temozolomide when Combined with Ionizing Radiation (IR) in Glioblastoma

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    Background: Glioblastoma is the most common primary adult brain tumor. Surgery followed by radiation therapy in combination with temozolomide (Tmz) produces a median survival of 14.6 months. Tmz is a DNA akylating agent that leads to the mispairing of guanine residues with thymine. An intact mismatch-repair mechanism (MMR) converts the mispaired thymine into a lethal double-strand DNA break. Vorinostat (SAHA), an HDAC inhibitor, has been shown to act as a radiosensitizer, possibly through inhibition of DNA repair. SAHA has successfully been combined with a number of cytotoxic agents. We hypothesized that SAHA would further potentiate the radiosensitizing properties of Tmz in glioblastoma. American Association for Cancer Research (AACR) 101st Annual Meeting April 17-21, Washington, D

    Therapeutic Challenge with a CDK 4/6 Inhibitor Induces an RB-Dependent SMAC-Mediated Apoptotic Response in Non-Small Cell Lung Cancer.

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    Purpose: The retinoblastoma tumor suppressor (RB), a key regulator of cell-cycle progression and proliferation, is functionally suppressed in up to 50% of non-small cell lung cancer (NSCLC). RB function is exquisitely controlled by a series of proteins, including the CyclinD-CDK4/6 complex. In this study, we interrogated the capacity of a CDK4/6 inhibitor, palbociclib, to activate RB function. Experimental Design and Results: We employed multiple isogenic RB-proficient and -deficient NSCLC lines to interrogate the cytostatic and cytotoxic capacity of CDK 4/6 inhibition in vitro and in vivo We demonstrate that while short-term exposure to palbociclib induces cellular senescence, prolonged exposure results in inhibition of tumor growth. Mechanistically, CDK 4/6 inhibition induces a proapoptotic transcriptional program through suppression of IAPs FOXM1 and Survivin, while simultaneously augmenting expression of SMAC and caspase-3 in an RB-dependent manner. Conclusions: This study uncovers a novel function of RB activation to induce cellular apoptosis through therapeutic administration of a palbociclib and provides a rationale for the clinical evaluation of CDK 4/6 inhibitors in the treatment of patients with NSCLC

    Calcium-dependent translocation of sorcin to membranes: functional relevance in contractile tissue

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    AbstractSorcin, a 22 kDa calcium binding protein present in abundance in cardiac tissue and in multi-drug resistant cells and previously described as a soluble protein, is now shown to undergo a calcium-dependent translocation process from the cytosol to cellular membranes in both systems. The translocation process takes place also in E. coli BL21 cells that express recombinant sorcin, r-sorcin, and can be exploited in the purification of the protein. Calcium binding to purified r-sorcin occurs at micromolar concentrations of the metal and is accompanied by a conformational change that renders the protein soluble in the non-ionic detergent Triton X-114. This finding suggests that lipids are the target of sorcin on cellular membranes. The possible significance of the calcium-dependent translocation of sorcin in the specialized functions of sorcin-expressing cells is discussed

    Genomic Classifier Augments the Role of Pathological Features in Identifying Optimal Candidates for Adjuvant Radiation Therapy in Patients With Prostate Cancer: Development and Internal Validation of a Multivariable Prognostic Model.

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    Purpose Despite documented oncologic benefit, use of postoperative adjuvant radiotherapy (aRT) in patients with prostate cancer is still limited in the United States. We aimed to develop and internally validate a risk-stratification tool incorporating the Decipher score, along with routinely available clinicopathologic features, to identify patients who would benefit the most from aRT. Patient and Methods Our cohort included 512 patients with prostate cancer treated with radical prostatectomy at one of four US academic centers between 1990 and 2010. All patients had ≥ pT3a disease, positive surgical margins, and/or pathologic lymph node invasion. Multivariable Cox regression analysis tested the relationship between available predictors (including Decipher score) and clinical recurrence (CR), which were then used to develop a novel risk-stratification tool. Our study adhered to the Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis guidelines for development of prognostic models. Results Overall, 21.9% of patients received aRT. Median follow-up in censored patients was 8.3 years. The 10-year CR rate was 4.9% vs. 17.4% in patients treated with aRT versus initial observation ( P \u3c .001). Pathologic T3b/T4 stage, Gleason score 8-10, lymph node invasion, and Decipher score \u3e 0.6 were independent predictors of CR (all P \u3c .01). The cumulative number of risk factors was 0, 1, 2, and 3 to 4 in 46.5%, 28.9%, 17.2%, and 7.4% of patients, respectively. aRT was associated with decreased CR rate in patients with two or more risk factors (10-year CR rate 10.1% in aRT v 42.1% in initial observation; P = .012), but not in those with fewer than two risk factors ( P = .18). Conclusion Using the new model to indicate aRT might reduce overtreatment, decrease unnecessary adverse effects, and reduce risk of CR in the subset of patients (approximately 25% of all patients with aggressive pathologic disease in our cohort) who benefit from this therapy
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