Now showing items 21-40 of 133

    • Optimization of the injected activity in dynamic 3D PET: a generalized approach using patient-specific NECs as demonstrated by a series of 15O-H2O scans.

      Walker, Mathew D; Matthews, Julian C; Asselin, Marie-Claude; Saleem, Azeem; Dickinson, Clare; Charnley, Natalie; Julyan, Peter J; Price, Patricia M; Jones, Terry; School of Cancer and Imaging Sciences, Wolfson Molecular Imaging Centre, University of Manchester, Manchester, United Kingdom. (2009-01-30)
    • Preliminary study of oxygen-enhanced longitudinal relaxation in MRI: a potential novel biomarker of oxygenation changes in solid tumors.

      O'Connor, James P B; Naish, Josephine H; Parker, Geoff J M; Waterton, John C; Watson, Yvonne; Jayson, Gordon C; Buonaccorsi, Giovanni A; Cheung, Susan; Buckley, David L; McGrath, Deirdre M; et al. (2009-11-15)
      PURPOSE: There is considerable interest in developing non-invasive methods of mapping tumor hypoxia. Changes in tissue oxygen concentration produce proportional changes in the magnetic resonance imaging (MRI) longitudinal relaxation rate (R(1)). This technique has been used previously to evaluate oxygen delivery to healthy tissues and is distinct from blood oxygenation level-dependent (BOLD) imaging. Here we report application of this method to detect alteration in tumor oxygenation status. METHODS AND MATERIALS: Ten patients with advanced cancer of the abdomen and pelvis underwent serial measurement of tumor R(1) while breathing medical air (21% oxygen) followed by 100% oxygen (oxygen-enhanced MRI). Gadolinium-based dynamic contrast-enhanced MRI was then performed to compare the spatial distribution of perfusion with that of oxygen-induced DeltaR(1). RESULTS: DeltaR(1) showed significant increases of 0.021 to 0.058 s(-1) in eight patients with either locally recurrent tumor from cervical and hepatocellular carcinomas or metastases from ovarian and colorectal carcinomas. In general, there was congruency between perfusion and oxygen concentration. However, regional mismatch was observed in some tumor cores. Here, moderate gadolinium uptake (consistent with moderate perfusion) was associated with low area under the DeltaR(1) curve (consistent with minimal increase in oxygen concentration). CONCLUSIONS: These results provide evidence that oxygen-enhanced longitudinal relaxation can monitor changes in tumor oxygen concentration. The technique shows promise in identifying hypoxic regions within tumors and may enable spatial mapping of change in tumor oxygen concentration.
    • Quantifying antivascular effects of monoclonal antibodies to vascular endothelial growth factor: insights from imaging.

      O'Connor, James P B; Carano, Richard A D; Clamp, Andrew R; Ross, Jed; Ho, Calvin C K; Jackson, Alan; Parker, Geoff J M; Rose, Chris J; Peale, Franklin V; Friesenhahn, Michel; et al. (2009)
    • Assessment of bladder motion for clinical radiotherapy practice using cine-magnetic resonance imaging.

      McBain, Catherine A; Khoo, Vincent S; Buckley, David L; Sykes, Jonathan S; Green, Melanie M; Cowan, Richard A; Hutchinson, Charles E; Moore, Christopher J; Price, Patricia M; Academic Department of Radiation Oncology, The University of Manchester, Christie Hospital NHS Foundation Trust, Wilmslow Road, Manchester, United Kingdom. (2009-11-01)
      PURPOSE: Organ motion is recognized as the principal source of inaccuracy in bladder radiotherapy (RT), but there is currently little information on intrafraction bladder motion. METHODS AND MATERIALS: We used cine-magnetic resonance imaging (cine-MRI) to study bladder motion relevant to intrafraction RT delivery. On two occasions, a 28 minute cine-MRI sequence was acquired from 10 bladder cancer patients and 5 control participants immediately after bladder emptying, after abstinence from drinking for the preceding hour. From the resulting cine sequences, bladder motion was subjectively assessed. To quantify bladder motion, the bladder was contoured in imaging volume sets at 0, 14, and 28 min to measure changes to bladder volumes, wall displacements, and center of gravity (COG) over time. RESULTS: The dominant source of bladder motion during imaging was bladder filling (up to 101% volume increase); rectal and small bowel movements were transient, with minimal impact. Bladder volume changes were similar for all participants. However for bladder cancer patients, wall displacements were larger (up to 58 mm), less symmetrical, and more variable compared with nondiseased control bladders. CONCLUSIONS: Significant and individualized intrafraction bladder wall displacements may occur during bladder RT delivery. This important source of inaccuracy should be incorporated into treatment planning and verification.
    • Ectopic HOXB4 overcomes the inhibitory effect of tumor necrosis factor-{alpha} on Fanconi anemia hematopoietic stem and progenitor cells.

      Milsom, Michael D; Schiedlmeier, Bernhard; Bailey, Jeff; Kim, Mi-Ok; Li, Dandan; Jansen, Michael; Ali, Abdullah Mahmood; Kirby, Michelle; Baum, Christopher; Fairbairn, Leslie J; et al. (2009-05-21)
      Ectopic delivery of HOXB4 elicits the expansion of engrafting hematopoietic stem cells (HSCs). We hypothesized that inhibition of tumor necrosis factor-alpha (TNF-alpha) signaling may be central to the self-renewal signature of HOXB4. Because HSCs derived from Fanconi anemia (FA) knockout mice are hypersensitive to TNF-alpha, we studied Fancc(-/-) HSCs to determine the physiologic effects of HOXB4 on TNF-alpha sensitivity and the relationship of these effects to the engraftment defect of FA HSCs. Overexpression of HOXB4 reversed the in vitro hypersensitivity to TNF-alpha of Fancc(-/-) HSCs and progenitors (P) and partially rescued the engraftment defect of these cells. Coexpression of HOXB4 and the correcting FA-C protein resulted in full correction compared with wild-type (WT) HSCs. Ectopic expression of HOXB4 resulted in a reduction in both apoptosis and reactive oxygen species in Fancc(-/-) but not WT HSC/P. HOXB4 overexpression was also associated with a significant reduction in surface expression of TNF-alpha receptors on Fancc(-/-) HSC/P. Finally, enhanced engraftment was seen even when HOXB4 was expressed in a time-limited fashion during in vivo reconstitution. Thus, the HOXB4 engraftment signature may be related to its effects on TNF-alpha signaling, and this pathway may be a molecular target for timed pharmacologic manipulation of HSC during reconstitution.
    • Strong association of the HLA-DP6 supertype with childhood leukaemia is due to a single allele, DPB1*0601.

      Taylor, G M; Hussain, A; Verhage, V; Thompson, P D; Fergusson, W D; Watkins, Gillian R; Lightfoot, T; Harrison, Christine J; Birch, Jillian M; Cancer Immunogenetics Group, School of Cancer and Imaging Sciences, University of Manchester, St Mary's Hospital, Manchester, UK. gmtaylor@manchester.ac.uk (2009-05)
      We previously reported that susceptibility to childhood B cell precursor ALL (BCP ALL) is associated with HLA-DPB1 alleles having glutamic acid (E) rather than lysine (K) in the P4 antigenic peptide-binding pocket. Clustering approximately 90% of DPB1 alleles into DPB69E (DP2, 6, 8) and DPB69K (DP1, 3, 4) supertypes revealed that DP2 and DP8 are associated with BCP ALL, but DP6 is also associated with non-BCP leukaemia. Here, we report that only one of seven alleles with the DP6 supertype (DPB1(*)0601) is associated with childhood leukaemia (leukaemia vs controls: odds ratio, 95% confidence interval [OR, CI]: 4.6, 2.0-10.4; corrected P=0.019), but not with childhood solid tumours or lymphomas. DPB1(*)0601 is also significantly associated with leukaemia subtypes, including BCP ALL, Pro-B ALL, T-ALL and AML. DPB1(*)0601 is significantly over-transmitted (76.9%) from parents to children with BCP ALL (OR; CI: 4.7; 1.01-22.2). Sequencing the coding region of DPB1(*)0601 revealed an exon 1-4 haplotype [T-DEAV-KIL-RVI] shared with DPB1(*)0301 and 0901, but no evidence of germline mutations in childhood leukaemia. These results suggest that the DPbeta0601 molecule may be functionally involved in childhood leukaemia. Analysis of peptide binding and T-cell activation by DPbeta0601-peptide complexes should help determine its role in childhood leukaemia causation.
    • Methods comparison for high-resolution transcriptional analysis of archival material on Affymetrix Plus 2.0 and Exon 1.0 microarrays.

      Linton, Kim M; Hey, Yvonne; Dibben, Sian; Miller, Crispin J; Freemont, Anthony J; Radford, John A; Pepper, Stuart D; Cancer Research UK Department of Medical Oncology, The Christie NHS Foundation Trust, Manchester, UK. kim.linton@christie.nhs.uk (2009-07)
      Microarray gene expression profiling of formalin-fixed paraffin-embedded (FFPE) tissues is a new and evolving technique. This report compares transcript detection rates on Affymetrix U133 Plus 2.0 and Human Exon 1.0 ST GeneChips across several RNA extraction and target labeling protocols, using routinely collected archival FFPE samples. All RNA extraction protocols tested (Ambion-Optimum, Ambion-RecoverAll, and Qiagen-RNeasy FFPE) provided extracts suitable for microarray hybridization. Compared with Affymetrix One-Cycle labeled extracts, NuGEN system protocols utilizing oligo(dT) and random hexamer primers, and cDNA target preparations instead of cRNA, achieved percent present rates up to 55% on Plus 2.0 arrays. Based on two paired-sample analyses, at 90% specificity this equalled an average 30 percentage-point increase (from 50% to 80%) in FFPE transcript sensitivity relative to fresh frozen tissues, which we have assumed to have 100% sensitivity and specificity. The high content of Exon arrays, with multiple probe sets per exon, improved FFPE sensitivity to 92% at 96% specificity, corresponding to an absolute increase of ~600 genes over Plus 2.0 arrays. While larger series are needed to confirm high correspondence between fresh-frozen and FFPE expression patterns, these data suggest that both Plus 2.0 and Exon arrays are suitable platforms for FFPE microarray expression analyses.
    • The impact of primary tumour origins in patients with advanced oesophageal, oesophago-gastric junction and gastric adenocarcinoma--individual patient data from 1775 patients in four randomised controlled trials.

      Chau, I; Norman, A R; Cunningham, D; Oates, J; Hawkins, Robert E; Iveson, T; Nicolson, M; Harper, P; Seymour, M; Hickish, T; et al. (2009-05)
      BACKGROUND: It is unclear if differential chemotherapy effects exist on overall survival (OS), response rate (RR) and toxicity depending on primary tumour origin [oesophageal versus oesophago-gastric junction (OGJ) versus gastric adenocarcinoma]. PATIENTS AND METHODS: A total of 2110 patients were enrolled in four randomised controlled trials (RCTs) assessing fluoropyrimidine +/- platinum-based chemotherapy. This analysis used individual patient data and restricted to patients with adenocarcinoma who received one or more dose of chemotherapy. Gastric origin was the control in comparisons of tumour origin. RESULTS: Of the 2110 patients randomised, 1775 (84%) patients had adenocarcinoma with oesophageal (n = 485), OGJ (n = 457) and gastric (n = 833) origins. The median OS was 9.5 months in oesophageal, 9.3 months in OGJ and 8.7 months in gastric cancer (P = 0.68). RR was 44.1% in oesophageal, 41.1% in OGJ and 35.6% in gastric cancers (P = 0.11 and 0.27, respectively, compared with gastric cancer on multivariate analysis). Toxicity composite end point occurred in 46%, 47% and 45% in oesophageal, OGJ and gastric cancers, respectively (P = 0.85 and 0.62 compared with gastric). CONCLUSIONS: In our large multicentre RCT dataset, no significant differences were demonstrated on multivariate analyses in OS, RR and toxic effects among patients with advanced oesophageal, OGJ and gastric adenocarcinoma. Future RCTs should not exclude oesophageal adenocarcinoma.
    • Magnetic order in a spin-half interpolating square-triangle Heisenberg antiferromagnet

      Bishop, R F; Li, P H Y; Farnell, Damian J J; Campbell, C E; School of Physics and Astronomy, Schuster Building, The University of Manchester, Manchester, M13 9PL, UK (2009)
    • The radiobiology/radiation protection interface in healthcare.

      Martin, C J; Sutton, D G; West, Catharine M L; Wright, Eric G; Department of Clinical Physics and Bio-engineering, Gartnavel Royal Hospital, Glasgow, UK. (2009-06)
      The current knowledge of radiation effects is reviewed and implications for its application in healthcare considered. The 21st L H Gray conference gathered leading experts in radiobiology, radiation epidemiology, radiation effect modelling, and the application of radiation in medicine to provide an overview of the subject. The latest radiobiology research in non-targeted effects such as genomic instability and the bystander effect challenge the old models, but the implications for health effects on humans are uncertain. Adaptive responses to external stresses, of which radiation is one, have been demonstrated in cells and animal models, but it is not known how these might modify human dose-effect relationships. Epidemiological evidence from the Japanese A-bomb survivors provides strong evidence that there is a linear relationship between the excess risk of cancer and organ dose that extends from about 50 mSv up to 2.5 Sv, and results from pooled data for multiple epidemiological studies indicate that risks extend down to doses of 20 mSv. Thus linear extrapolation of the A-bomb dose-effect data provides an appropriate basis for radiological protection standards at the present time. Risks from higher dose diagnostic procedures fall within the range in which health effects can be demonstrated. There is therefore reason for concern about the rise in the number of computed tomography (CT) scans performed in many countries, and in particular the use of CT for screening of asymptomatic individuals. New radiotherapy techniques allow high dose radiation fields to be conformed more effectively to target volumes, and reduce doses to critical organs, but they tend to give a higher and more uniform dose to the whole body which may increase the risk of second cancer. It is important that radiation protection practitioners keep abreast of developments in understanding of radiation effects and advise the medical community about the implications of fundamental research when planning medical applications for the future.
    • A FTIR microspectroscopic study of the uptake and metabolism of isotopically labelled fatty acids by metastatic prostate cancer.

      Gazi, Ehsan; Harvey, Tim J; Brown, Michael D; Lockyer, Nicholas P; Gardner, Peter; Clarke, Noel W; Genito Urinary Cancer research Group, School of Cancer and Imaging Sciences, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester M20 4BX, UK (2009)
    • Predicting the myelotoxicity of chemotherapy: the use of pretreatment O6-methylguanine-DNA methyltransferase determination in peripheral blood mononuclear cells.

      Sabharwal, A; Waters, R; Danson, Sarah; Clamp, Andrew R; Lorigan, Paul C; Thatcher, Nick; Margison, Geoffrey P; Middleton, Mark R; Department of Medical Oncology, University of Oxford, Oxford, UK. (2011-12-21)
      To assess the value of pretreatment O-methylguanine-DNA methyltransferase (MGMT) expression in peripheral blood mononuclear cells (PBMCs) in predicting haematological toxicity with O-alkylating agent chemotherapy, we explored this relationship retrospectively in melanoma patients. Ninety-three patients treated with temozolomide or dacarbazine in four clinical trials were assessed, and a model of the interaction between MGMT expression and haematological toxicity was constructed. Nadir white-cell and platelet counts were related to, and hence could be predicted from, pretreatment MGMT. Leucopenia and thrombocytopenia were more prevalent amongst patients with low pretreatment MGMT, according to the highest grades of toxicity experienced and/or the dose intensity patients could sustain. Addition of interferon to chemotherapy or compression of the temozolomide schedule increased the toxicity. The model also predicts significant myelotoxicity where PBMC MGMT is inactivated, consistent with the experience in the clinic with lomeguatrib and O-benzylguanine. Determination of MGMT in PBMC can identify patients at greatest risk of toxicity or who are suitable for dose intensification.
    • A novel imaging technique for fusion of high-quality immobilised MR images of the head and neck with CT scans for radiotherapy target delineation.

      Webster, Gareth J; Kilgallon, J E; Ho, Kean F; Rowbottom, Carl G; Slevin, Nicholas J; Mackay, Ranald I; North Western Medical Physics, Christie Hospital NHS Foundation Trust, Manchester, UK. gareth.webster@physics.cr.man.ac.uk (2009-06)
      Uncertainty and inconsistency are observed in target volume delineation in the head and neck for radiotherapy treatment planning based only on CT imaging. Alternative modalities such as MRI have previously been incorporated into the delineation process to provide additional anatomical information. This work aims to improve on previous studies by combining good image quality with precise patient immobilisation in order to maintain patient position between scans. MR images were acquired using quadrature coils placed over the head and neck while the patient was immobilised in the treatment position using a five-point thermoplastic shell. The MR image and CT images were automatically fused in the Pinnacle treatment planning system using Syntegra software. Image quality, distortion and accuracy of the image registration using patient anatomy were evaluated. Image quality was found to be superior to that acquired using the body coil, while distortion was < 1.0 mm to a radius of 8.7 cm from the scan centre. Image registration accuracy was found to be 2.2 mm (+/- 0.9 mm) and < 3.0 degrees (n = 6). A novel MRI technique that combines good image quality with patient immobilization has been developed and is now in clinical use. The scan duration of approximately 15 min has been well tolerated by all patients.
    • Phase I dose escalation, pharmacokinetic and pharmacodynamic study of naptumomab estafenatox alone in patients with advanced cancer and with docetaxel in patients with advanced non-small-cell lung cancer

      Borghaei, Hossein; Alpaugh, Katherine; Hedlund, Gunnar; Forsberg, Goran; Langer, Corey J; Rogatko, Andre; Hawkins, Robert E; Dueland Svein; Lassen, Ulrik; Cohen, Roger B; et al. (2009)
    • Monoclonal antibodies directed to CD20 and HLA-DR can elicit homotypic adhesion followed by lysosome-mediated cell death in human lymphoma and leukemia cells.

      Ivanov, Andrei; Beers, Stephen A; Walshe, Claire A; Honeychurch, Jamie; Alduaij, Waleed; Cox, Kerry L; Potter, Kathleen N; Murray, Stephen M; Chan, Claude H T; Klymenko, Tetyana; et al. (2009-08)
      mAbs are becoming increasingly utilized in the treatment of lymphoid disorders. Although Fc-FcgammaR interactions are thought to account for much of their therapeutic effect, this does not explain why certain mAb specificities are more potent than others. An additional effector mechanism underlying the action of some mAbs is the direct induction of cell death. Previously, we demonstrated that certain CD20-specific mAbs (which we termed type II mAbs) evoke a nonapoptotic mode of cell death that appears to be linked with the induction of homotypic adhesion. Here, we reveal that peripheral relocalization of actin is critical for the adhesion and cell death induced by both the type II CD20-specific mAb tositumomab and an HLA-DR-specific mAb in both human lymphoma cell lines and primary chronic lymphocytic leukemia cells. The cell death elicited was rapid, nonapoptotic, nonautophagic, and dependent on the integrity of plasma membrane cholesterol and activation of the V-type ATPase. This cytoplasmic cell death involved lysosomes, which swelled and then dispersed their contents, including cathepsin B, into the cytoplasm and surrounding environment. The resulting loss of plasma membrane integrity occurred independently of caspases and was not controlled by Bcl-2. These experiments provide what we believe to be new insights into the mechanisms by which 2 clinically relevant mAbs elicit cell death and show that this homotypic adhesion-related cell death occurs through a lysosome-dependent pathway.
    • Frequency of human T regulatory cells in peripheral blood is significantly reduced by cryopreservation.

      Elkord, Eyad; Clinical Immunotherapy Laboratory, Department of Medical Oncology, University of Manchester, Wilmslow Road, Manchester M204BX, UK. eelkord@picr.man.ac.uk (2009-08-15)
      Cryopreservation of peripheral blood mononuclear cells (PBMC) is essential for many clinical and research assays. Some studies reported consistent changes in PBMC phenotype following cryopreservation. We hypothesized that PBMC freezing may have a negative impact on estimation of the frequency of T regulatory cell (Treg). Treg levels were measured in 6 fresh PBMC samples isolated from 6 healthy donors and these levels were re-measured after freezing for three weeks. Herein, we report a significant reduction in Treg frequency in all samples following cryopreservation.
    • Flipping of alkylated DNA damage bridges base and nucleotide excision repair.

      Tubbs, Julie L; Latypov, Vitaly F; Kanugula, Sreenivas; Butt, Amna; Melikishvili, Manana; Kraehenbuehl, Rolf; Fleck, Oliver; Marriott, Andrew S; Watson, Amanda J; Verbeek, Barbara; et al. (2009-06-11)
      Alkyltransferase-like proteins (ATLs) share functional motifs with the cancer chemotherapy target O(6)-alkylguanine-DNA alkyltransferase (AGT) and paradoxically protect cells from the biological effects of DNA alkylation damage, despite lacking the reactive cysteine and alkyltransferase activity of AGT. Here we determine Schizosaccharomyces pombe ATL structures without and with damaged DNA containing the endogenous lesion O(6)-methylguanine or cigarette-smoke-derived O(6)-4-(3-pyridyl)-4-oxobutylguanine. These results reveal non-enzymatic DNA nucleotide flipping plus increased DNA distortion and binding pocket size compared to AGT. Our analysis of lesion-binding site conservation identifies new ATLs in sea anemone and ancestral archaea, indicating that ATL interactions are ancestral to present-day repair pathways in all domains of life. Genetic connections to mammalian XPG (also known as ERCC5) and ERCC1 in S. pombe homologues Rad13 and Swi10 and biochemical interactions with Escherichia coli UvrA and UvrC combined with structural results reveal that ATLs sculpt alkylated DNA to create a genetic and structural intersection of base damage processing with nucleotide excision repair.
    • High-order coupled cluster method study of frustrated and unfrustrated quantum magnets in external magnetic fields.

      Farnell, Damian J J; Zinke, R; Schulenburg, J; Richter, J; Academic Department of Radiation Oncology, Faculty of Medical and Human Sciences, University of Manchester, c/o The Christie NHS Foundation Trust, Manchester M20 4BX, UK (2009)
    • Retrovirally-mediated genetic correction of mesenchymal stem cells from patients affected by mucopolysaccharidosis type II (Hunter Syndrome)

      Corradi-Perini, Carla; Southgate, Thomas D; Besley, Guy T N; Cooper, Alan; Deakin, Jon A; Wraith, J Ed; Fairbairn, Leslie J; Wynn, Robert F; Bellantuono, Ilaria; Stem Cell Research Group, Royal Manchester Children's Hospital, Manchester. (2008)