112 research outputs found

    Beyond-brand effect of television food advertisements on food choice in children: The effects of weight status

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    Copyright © The Authors 2007.Objective - To investigate the effect of television food advertising on children’s food intake, specifically whether childhood obesity is related to a greater susceptibility to food promotion. Design - The study was a within-subject, counterbalanced design. The children were tested on two occasions separated by two weeks. One condition involved the children viewing food advertisements followed by a cartoon, in the other condition the children viewed non-food adverts followed by the same cartoon. Following the cartoon, their food intake and choice was assessed in a standard paradigm. Setting - The study was conducted in Liverpool, UK. Subjects - Fifty-nine children (32 male, 27 female) aged 9–11 years were recruited from a UK school to participate in the study. Thirty-three children were normal-weight (NW), 15 overweight (OW) and 11 obese (OB). Results - Exposure to food adverts produced substantial and significant increases in energy intake in all children (P < 0·001). The increase in intake was largest in the obese children (P = 0·04). All children increased their consumption of high-fat and/or sweet energy-dense snacks in response to the adverts (P < 0·001). In the food advert condition, total intake and the intake of these specific snack items correlated with the children’s modified age- and gender-specific body mass index score. Conclusions - These data suggest that obese and overweight children are indeed more responsive to food promotion, which specifically stimulates the intake of energy-dense snacks.University of Liverpoo

    Stress, nutrients and genotype: understanding and managing asparagine accumulation in wheat grain

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    Plant stress and poor crop management strategies compromise the foundations of food security: crop yield, nutritional quality and food safety. Accumulation of high concentrations of the amino acid asparagine in its free (soluble, non-protein) form is an example of an undesirable outcome of stress for the nutritional quality and food safety of wheat because of its role as a precursor to acrylamide, a carcinogenic processing contaminant. In this review, we cover what is known about the mechanisms and functions of free asparagine accumulation in the grain during normal development and particularly during stress in wheat. Comparisons with other plant species, yeast, and mammals are drawn in order to gain deeper insight into the conserved biology underlying asparagine accumulation. Crop management strategies and practices are discussed in the context of managing asparagine accumulation, which must be balanced against other desirable goals, such as sustainability, protein content and yield

    A Dominant Role for the Immunoproteasome in CD8+ T Cell Responses to Murine Cytomegalovirus

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    Murine cytomegalovirus (MCMV) is an important animal model of human cytomegalovirus (HCMV), a β-Herpesvirus that infects the majority of the world's population and causes disease in neonates and immunocompromised adults. CD8+ T cells are a major part of the immune response to MCMV and HCMV. Processing of peptides for presentation to CD8+ T cells may be critically dependent on the immunoproteasome, expression of which is affected by MCMV. However, the overall importance of the immunoproteasome in the generation of immunodominant peptides from MCMV is not known. We therefore examined the role of the immunoproteasome in stimulation of CD8+ T cell responses to MCMV – both conventional memory responses and those undergoing long-term expansion or “inflation”. We infected LMP7−/− and C57BL/6 mice with MCMV or with newly-generated recombinant vaccinia viruses (rVVs) encoding the immunodominant MCMV protein M45 in either full-length or epitope-only minigene form. We analysed CD8+ T cell responses using intracellular cytokine stain (ICS) and MHC Class I tetramer staining for a panel of MCMV-derived epitopes. We showed a critical role for immunoproteasome in MCMV affecting all epitopes studied. Interestingly we found that memory “inflating” epitopes demonstrate reduced immunoproteasome dependence compared to non-inflating epitopes. M45-specific responses induced by rVVs remain immunoproteasome-dependent. These results help to define a critical restriction point for CD8+ T cell epitopes in natural cytomegalovirus (CMV) infection and potentially in vaccine strategies against this and other viruses

    Understanding the relationships between free asparagine in grain and other traits to breed low-asparagine wheat

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    Since the discovery of acrylamide in food, and the identification of free asparagine as the key determinant of acrylamide concentration in wheat products, our understanding of how grain asparagine content is regulated has improved greatly. However, the targeted reduction in grain asparagine content has not been widely implemented in breeding programmes so far. Here we summarise how free asparagine concentration relates to other quality and agronomic traits and show that these relationships are unlikely to pose major issues for the breeding of low-asparagine wheat. We also outline the strategies that are possible for the breeding of low-asparagine wheat, using both natural and induced variation

    Pharmacokinetics, safety and tolerability of olaparib and temozolomide for recurrent glioblastoma: results of the phase I OPARATIC trial

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    Background: The poly(ADP-ribose) polymerase (PARP) inhibitor olaparib potentiated radiation and temozolomide chemotherapy in pre-clinical glioblastoma models but brain penetration was poor. Clinically, PARP inhibitors exacerbate the hematological side-effects of temozolomide. The OPARATIC trial was conducted to measure penetration of recurrent glioblastoma by olaparib, and assess the safety and tolerability of its combination with temozolomide. Methods: Pre-clinical pharmacokinetic studies evaluated olaparib tissue distribution in rats and tumor-bearing mice. Adult patients with recurrent glioblastoma received various doses and schedules of olaparib and low-dose temozolomide in a 3+3 design. Suitable patients received olaparib prior to neurosurgical resection; olaparib concentrations in plasma, tumour core and tumour margin specimens were measured by mass spectrometry. A dose expansion cohort tested tolerability and efficacy of the recommended phase II dose (RP2D). Radiosensitizing effects of olaparib were measured by clonogenic survival in glioblastoma cell lines. Results: Olaparib was a substrate for multi-drug resistance protein-1 and showed no brain penetration in rats but was detected in orthotopic glioblastoma xenografts. Clinically, olaparib was detected in 71/71 tumor core specimens (27 patients, median 496nM) and 21/21 tumor margin specimens (9 patients, median 512.3nM). Olaparib exacerbated TMZ-related hematological toxicity, necessitating intermittent dosing. RP2D was olaparib 150mg (3 days/week) with TMZ 75mg/m2 daily for 42 days. Fourteen (36%) of 39 evaluable patients were progression-free at 6 months. Olaparib radiosensitized six glioblastoma cell lines at clinically relevant concentrations of 100 and 500 nM. Conclusions: Olaparib reliably penetrates recurrent glioblastoma at radiosensitizing concentrations, supporting further clinical development and highlighting the need for better pre-clinical models

    Investigations of the novel checkpoint kinase 1 inhibitor SRA737 in non-small cell lung cancer and colorectal cancer cells of differing tumour protein 53 gene status

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    Aim: In response to DNA damage the serine/threonine-specific protein kinase checkpoint kinase 1 (CHK1) is activated allowing cells to enter S phase (S) and G2 phase (G2) cell-cycle arrest. CHK1 inhibitors are expected to prevent cells from entering such arrest, thereby enhancing DNA damage-induced cytotoxicity. In contrast, normal cells with intact ataxia–telangiectasia mutated (ATM), CHK2 and tumour suppressor protein 53 (P53) signalling are still able to enter cell-cycle arrest using the functioning G1/S checkpoint, thereby being rescued from enhanced cytotoxicity. The main objective of this work is to investigate the in vitro effects of the novel CHK1 inhibitor SRA737 on pairs of non-small cell lung cancer (NSCLC) and colorectal cancer (CRC) cell lines, all with genetic aberrations rendering them susceptible to replication stress but of differing tumour protein 53 (TP53) gene status, focusing on DNA damage induction and the subsequent effects on cell proliferation and viability. Methods: NSCLC cell lines H23 [TP53 mutant (MUT)] and A549 [TP53 wild-type (WT)] and CRC cell lines HT29 (TP53 MUT) and HCT116 (TP53 WT) were incubated with differing micromolar concentrations of SRA737 for 24 h and then analysed using alkaline comet and phosphorylated H2A.X variant histone (γH2AX)-foci assays to assess mostly DNA single strand break and double strand break damage, respectively. Cell-counting/trypan blue staining was also performed to assess cell proliferation/viability. Results: Clear concentration-dependent increases in comet formation and γH2AX-foci/cell were noted for the TP53 MUT cells with no or lower increases being noted in the corresponding TP53 WT cells. Also, greater anti-proliferative and cell killing effects were noted in the TP53 MUT cells than in the TP53 WT cells. Conclusions: This study’s data suggests that P53 status/functioning is a key factor in determining the sensitivity of NSCLC and CRC cancer cells towards CHK1 inhibition, even in circumstances conducive to high replicative stress
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