• Biomonitoring human exposure to environmental carcinogenic chemicals.

      Farmer, P; Sepai, O; Lawrence, R; Autrup, H; Sabro Nielsen, P; Vestergård, A; Waters, R; Leuratti, C; Jones, N; Stone, J; et al. (1996-07)
      A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of second biological effects (mutation and cytogenetic damage). Adduct detection at the level of DNA or protein (haemoglobin) was carried out by 32P-postlabelling, immunochemical, HPLC or mass spectrometric methods. Urinary excretion products resulting from DNA damage were also estimated (immunochemical assay, mass spectrometry). The measurement of adducts was focused on those from genotoxicants that result from petrochemical combustion or processing, e.g. low-molecular-weight alkylating agents, PAHs and compounds that cause oxidative DNA damage. Cytogenetic analysis of lymphocytes was undertaken (micronuclei, chromosome aberrations and sister chromatid exchanges) and mutation frequency was estimated at a number of loci including the hprt gene and genes involving in cancer development. Blood and urine samples from individuals exposed to urban pollution were collected. Populations exposed through occupational or medical sources to larger amounts of some of the genotoxic compounds present in the environmental samples were used as positive controls for the environmentally exposed population. Samples from rural areas were used as negative controls. The project has led to new, more sensitive and more selective approaches for detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers exposed to ethylene oxide in a sterilization plant. Dose reponse and adduct repair were studied for methylated adducts in patients treated with methylating cytostatic drugs. The biomonitoring methods have also demonstrated their potential for detecting environmental exposure to genotoxic compounds in nine groups of non-smoking individuals, 32P-postlabelling of DNA adducts being shown to have the greatest sensitivity.
    • Biophysical differentiation between lymphocytes from healthy donors, patients with malignant diseases and other disorders.

      Cercek, L; Cercek, B; Franklin, C I; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (1974-05)
      Changes in the structuredness of the cytoplasmic matrix (SCM) of human lymphocytes induced by PHA, CaBP and EF were studied with the technique of fluorescence polarization. The study suggests that the SCM test may offer a new and fast technique for the detection of malignant growth.
    • The bioreductive agent RH1 and gamma-irradiation both cause G2/M cell cycle phase arrest and polyploidy in a p53-mutated human breast cancer cell line.

      Kim, Joo-Young; Kim, Chul-Hwan; Stratford, Ian J; Patterson, Adam V; Hendry, Jolyon H; Cancer Research UK Group of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester, UK. jooyoungcasa@ncc.re.kr (2004-02-01)
      PURPOSE: RH1 is a newly developed bioreductive agent, and its bioactivation is mediated by the enzyme DT-diaphorase (DTD). We have shown previously that RH1 is highly cytotoxic against cells expressing high DTD, using the p53-mutated MDA231 human breast cancer cell line transfected with the DTD gene (D7 cells). We now report that both RH1 and gamma-irradiation cause D7 cells to arrest in the G2/M cell cycle phase and undergo polyploidy. The latter is a way of p53-mutated cells responding to DNA-damaging agents. Only a small proportion of the polyploid cells are clonogenic, hence polyploidy may contribute to the reproductive failure of the cells after RH1 and irradiation. Thus, we investigated the effect of RH1 and gamma-irradiation on the formation of polyploid cells and a sub-G1 population (as a measure of apoptosis) in relation to the G2/M cell cycle block. METHODS AND MATERIALS: MDA231 D7 cells were treated using a range of RH1 doses. The cells were irradiated using 2 Gy or 5 Gy gamma-rays either as a single dose or in combination with RH1. An IC(90) dose (dose to kill 90% of the cells) of RH1 was administered for 3 h followed by irradiation after a further 24 h. Subsequent changes in cell cycle and polyploidy (DNA content in excess of that of G2/M cells) were examined. RESULTS: Treatment of D7 cells with the RH1 resulted in 60-70% of cells arrested in the G2/M phase of the cell cycle by 24 h, which decreased to control levels by 48 h. Irradiation with 2 Gy and 5 Gy caused a similar G2/M block at 12-24 h, which was followed by a sharp decline at 24-48 h. In contrast, the same dose of radiation combined with RH1 held the cells in the G2/M phase up to 48 h, and this pattern reached pretreatment levels at 72-96 h. Most control cells were found to contain a small number of spontaneously arising polyploid cells. The development of polyploid cells was evident from 12 h after all treatments and showed a significant increase at 48 h and subsequently. As opposed to this, apoptosis measured by the sub-G1 cell population in DNA analyses showed a tendency to increase according to the elapsed time for each group of treatments. Single treatments with RH1 caused a significant increase in the apoptotic population between 48 and 120 h. The first significant increase in apoptosis was observed at 48 h for 5 Gy, 2 Gy + RH1, and 5 Gy + RH1 treatments, and showed a tendency to increase further at later times, but the 2 Gy dose gave an earlier apoptotic peak at 24 h, which decreased to 96 h. The addition of RH1 to the irradiation did not increase the formation of polyploid cells or apoptosis compared with radiation alone (2 Gy vs. RH1 + 2 Gy or 5 Gy vs. RH1 + 5 Gy). The higher dose of irradiation (5 Gy vs. 2 Gy) resulted in a significantly higher proportion of polyploid cells (but not of apoptotic cells) when used alone or in combination (5 Gy + RH1 vs. 2 Gy + RH1). CONCLUSIONS: Both RH1 and gamma-irradiation, individually and in combination, showed a significant G2/M block in MDA231 D7 breast cancer cells. The formation of polyploid cells was dependent more on the radiation dose rather than on the pretreatment with RH1. The polyploid cell population was observed after the G2/M cell cycle phase arrest, and it preceded the late increase of the apoptotic cell population. The role of polyploidy in cell reproductive failure in the total cell population is not known, but it appears to contribute to cytotoxicity in cells released from the G2/M cell cycle phase block.
    • A biospecimen proficiency testing program for biobank accreditation: four years of experience.

      Gaignaux, A; Ashton, Garry; Coppola, D; De Souza, Y; De Wilde, A; Eliason, J; Grizzle, W; Guadagni, F; Gunter, E; Koppandi, I; et al. (2016-05-19)
      Biobanks produce and distribute biospecimens, ensuring their fitness for purpose and accurately qualifying them before distribution. In their efforts toward professionalization, biobanks can nowadays seek certification or accreditation. One of the requirements of these standards is regular participation in Proficiency Testing (PT) programs. An international PT program has been developed and provided to biobanks and other laboratories that perform specific tests to qualify different types of biospecimens. This PT program includes biospecimen testing schemes, as well as biospecimen processing interlaboratory exercises. This PT program supports the development of biobank quality assurance by providing the possibility to assess biobank laboratory performance and useful insights into biobank laboratory method performance characteristics and thus fulfill the demands from accreditation authorities.
    • Bipyridylium quaternary salts and related compounds. Part 6.- Pulse radiolysis studies of the reaction of paraquat radical analogues with oxygen.

      Farrington, John A; Ebert, Michael; Land, Edward J; Paterson Laboratories, Christie Hospital and Holt Radium Institute, Manchester (1978)
    • Bipyridylium quaternary salts and related compounds. V. Pulse radiolysis studies of the reaction of paraquat radical with oxygen. Implications for the mode of action of bipyridyl herbicides.

      Farrington, J; Ebert, M P; Land, Edward J; Fletcher, K; Imperial Chemical Industries Ltd, Jealott's Hill Research Station, Bracknell, Berks, RG12 6EY (1973-09-26)
    • Black tea consumption and risk of skin cancer: an 11-year prospective study.

      Miura, K; Hughes, M; Arovah, N; van der Pols, J; Green, Adèle C; QIMR Berghofer Medical Research Institute, Cancer and Population Studies Group , Brisbane , Queensland , Australia (2015-10)
      Tea consumption has been shown to protect against skin carcinogenesis in laboratory-based studies; however, epidemiological evidence is limited and inconsistent. This prospective study examined the association between black tea consumption and the incidence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Usual black tea consumption was estimated from food frequency questionnaires completed in 1992, 1994, and 1996 by 1,325 Australian adults. All histologically confirmed skin cancers diagnosed in participants from 1997 to 2007 were recorded. Relative risks (RRs) and 95% confidence intervals (CIs) were assessed using generalized linear models with Poisson and negative binomial distributions and adjusted for confounding factors including skin phenotype and sun exposure. Compared with never drinking black tea, drinking ≥4 cups/day was not associated with BCC (RR = 1.03, 95% CI: 0.70-1.53; P-trend = 0.74) or SCC (RR = 1.25, 95% CI: 0.71-2.19; P-trend = 0.29) in person-based analyses. Stratification by previous history of skin cancer as well as tumor-based analyses also showed no significant associations between black tea intake and incidence of BCC or SCC tumors. Our results do not support the hypothesis that high black tea consumption reduces risk of skin cancer, including in people with a previous history of skin cancer.
    • Bladder tumor contains higher N7-methylguanine levels in DNA than adjacent normal bladder epithelium.

      Saad, Abir A; O'Connor, Peter J; Mostafa, Mostafa H; Metwalli, Nabila E; Cooper, Donald P; Margison, Geoffrey P; Povey, Andrew C; Cancer Research UK Carcinogenesis Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, Manchester. (2006-04)
      Schistosoma haematobium-infected patients are more likely to develop bladder cancer and be more exposed to carcinogenic N-nitroso compounds than uninfected patients. As N7-methylguanine is a marker of exposure to methylating agents of this type, we have measured N7-methyldeoxyguanosine 3'-monophosphate (N7-MedGp) by (32)P postlabeling. DNA was isolated from 42 paired normal and tumor tissue of Egyptians with bladder cancer. N7-MedGp was detected in DNA from 93% of the tumors and 74% of the normal bladder tissue samples. Adduct levels were highly variable and ranged from 0.04 to 6.4 and from 0.02 to 0.72 micromol/mol deoxyguanosine 3'-monophosphate (dGp) in tumor and normal DNA, respectively. N7-MedGp levels in normal and tumor DNA were highly correlated with one another (P = 0.007). The mean difference (95% confidence interval) in adduct levels between tumor and normal DNA was 0.21 (0.13-0.32) micromol/mol dGp and this was statistically significant (P < 0.001). The adduct ratio (tumor DNA/normal DNA) varied between 0.2 and 136 (median, 4.6). N7-MedGp levels were not associated with gender, age, or the presence of schistosomiasis. However, lower N7-MedGp levels were found in normal DNA from individuals lacking the GSTM1 gene (P = 0.03) but not the GSTT1 gene or in subjects with the Ile105Val GSTP1 polymorphism. These results show that exposure to methylating agents is widespread and suggest that such exposure may play a role both in tumor initiation and progression.
    • Blast cells surviving acute myeloid leukemia induction therapy are in cycle with a signature of FOXM1 activity

      Williams, Mark S; Basma, Naseer J; Amaral, Fabio M R; Wiseman, Daniel H; Somervaille, Tim C P; Leukaemia Biology Laboratory, Cancer Research UK Manchester Institute, Oglesby Cancer Research Building, The University of Manchester, 555 Wilmslow Road, Manchester, M20 4GJ, UK (2021)
      Background: Disease relapse remains common following treatment of acute myeloid leukemia (AML) and is due to chemoresistance of leukemia cells with disease repopulating potential. To date, attempts to define the characteristics of in vivo resistant blasts have focused on comparisons between leukemic cells at presentation and relapse. However, further treatment responses are often seen following relapse, suggesting that most blasts remain chemosensitive. We sought to characterise in vivo chemoresistant blasts by studying the transcriptional and genetic features of blasts from before and shortly after induction chemotherapy using paired samples from six patients with primary refractory AML. Methods: Leukemic blasts were isolated by fluorescence-activated cell sorting. Fluorescence in situ hybridization (FISH), targeted genetic sequencing and detailed immunophenotypic analysis were used to confirm that sorted cells were leukemic. Sorted blasts were subjected to RNA sequencing. Lentiviral vectors expressing short hairpin RNAs were used to assess the effect of FOXM1 knockdown on colony forming capacity, proliferative capacity and apoptosis in cell lines, primary AML cells and CD34+ cells from healthy donors. Results: Molecular genetic analysis revealed early clonal selection occurring after induction chemotherapy. Immunophenotypic characterisation found leukemia-associated immunophenotypes in all cases that persisted following treatment. Despite the genetic heterogeneity of the leukemias studied, transcriptional analysis found concerted changes in gene expression in resistant blasts. Remarkably, the gene expression signature suggested that post-chemotherapy blasts were more proliferative than those at presentation. Resistant blasts also appeared less differentiated and expressed leukemia stem cell (LSC) maintenance genes. However, the proportion of immunophenotypically defined LSCs appeared to decrease following treatment, with implications for the targeting of these cells on the basis of cell surface antigen expression. The refractory gene signature was highly enriched with targets of the transcription factor FOXM1. shRNA knockdown experiments demonstrated that the viability of primary AML cells, but not normal CD34+ cells, depended on FOXM1 expression. Conclusions: We found that chemorefractory blasts from leukemias with varied genetic backgrounds expressed a common transcriptional program. In contrast to the notion that LSC quiescence confers resistance to chemotherapy we find that refractory blasts are both actively proliferating and enriched with LSC maintenance genes. Using primary patient material from a relevant clinical context we also provide further support for the role of FOXM1 in chemotherapy resistance, proliferation and stem cell function in AML.
    • Blockade of growth factor receptors in ductal carcinoma in situ inhibits epithelial proliferation.

      Chan, K C; Knox, W F; Gandhi, A; Slamon, D J; Potten, Christopher S; Bundred, Nigel J; Department of Surgery, University Hospital of South Manchester, Manchester, UK. (2001-03)
      BACKGROUND: Ductal carcinoma in situ (DCIS) expresses c-erbB-2 receptor and epidermal growth factor receptor (EGFR). The aim of this study was to determine whether blocking of c-erbB-2 receptor with a humanized monoclonal antibody, 4D5 (HerceptinTM), or of EGFR with an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), ZD1839 (IressaTM), would decrease epithelial proliferation in DCIS. METHODS: DCIS tissue from 18 women undergoing surgery was implanted into 16 to 20 athymic nude mice per experiment (eight xenografts per mouse). Treatment commenced 2 weeks after implantation and consisted either of twice-weekly intraperitoneal injections of 4D5 10 mg/kg or of daily gavage with ZD1839 at 100-200 mg/kg for 14 days; appropriate controls were included. Xenografts were removed on days 14, 21 and 28. Proliferation was assessed by counting 1000 epithelial cells after Ki67 immuno- staining. RESULTS: ZD1839 inhibited proliferation compared with that in controls after 14 days (P < 0.01), whereas 4D5 did not. CONCLUSION: Proliferation in DCIS was decreased by EGFR tyrosine kinase inhibition but not by c-erbB-2 receptor blockade. ZD1839, an orally active and selective EGFR-TKI, has potential as adjuvant therapy in DCIS.
    • Blockade of platelet-derived growth factor receptor-beta by CDP860, a humanized, PEGylated di-Fab', leads to fluid accumulation and is associated with increased tumor vascularized volume.

      Jayson, Gordon C; Parker, Geoff J M; Mullamitha, Saifee A; Valle, Juan W; Saunders, Mark P; Broughton, Lynn; Lawrance, Jeremy A L; Carrington, Bernadette M; Roberts, Caleb; Issa, B; et al. (2005-02-10)
      PURPOSE: CDP860 is an engineered Fab' fragment-polyethylene glycol conjugate, which binds to and blocks the activity of the beta-subunit of the platelet-derived growth factor receptor (PDGFR-beta). Studies in animals have suggested that PDGFR-beta inhibition reduces tumor interstitial fluid pressure, and thus increases the uptake of concomitantly administered drugs. The purpose of this study was to determine whether changes in tumor vascular parameters could be detected in humans, and to assess whether CDP860 would be likely to increase the uptake of a concurrently administered small molecule in future studies. PATIENTS AND METHODS: Patients with advanced ovarian or colorectal cancer and good performance status received intravenous infusions of CDP860 on days 0 and 28. Patients had serial dynamic contrast-enhanced magnetic resonance imaging studies to measure changes in tumor vascular parameters. RESULTS: Three of eight patients developed significant ascites, and seven of eight showed evidence of fluid retention. In some patients, the ratio of vascular volume to total tumor volume increased significantly (P < .001) within 24 hours following CDP860 administration, an effect suggestive of recruitment of previously non-functioning vessels. CONCLUSION: These observations suggest that inhibition of PDGFR-beta might improve delivery of a concurrently administered therapy. However, in cancer patients, further exploration of the dosing regimen of CDP860 is required to dissociate adverse effects from beneficial effects. The findings challenge the view that inhibition of PDGF alone is beneficial, and confirm that effects of PDGFR kinase inhibition mediate, to some extent, the fluid retention observed in patients treated with mixed tyrosine kinase inhibitors.
    • Blocking phosphoinositide 3-kinase activity in colorectal cancer cells reduces proliferation but does not increase apoptosis alone or in combination with cytotoxic drugs

      Martin-Fernandez, Cristina; Bales, Juliana; Hodgkinson, Cassandra L; Welman, Arkadiusz; Welham, Melanie J; Dive, Caroline; Morrow, Christopher J; Paterson Institute for Cancer Research, University of Manchester, Manchester, United Kingdom (2009)
    • Blood cell generation from the hemangioblast.

      Lancrin, Christophe; Sroczynska, Patrycja; Serrano, Alicia G; Gandillet, Arnaud; Ferreras, Cristina; Kouskoff, Valerie; Lacaud, Georges; Cancer Research UK, Stem Cell Biology Group, Paterson Institute for Cancer Research, University of Manchester, Wilmslow Road, Manchester, M20 4BX, UK. (2010-02)
      Understanding how blood cells are generated is important from a biological perspective but also has potential implications in the treatment of blood diseases. Such knowledge could potentially lead to defining new conditions to amplify hematopoietic stem cells (HSCs) or could translate into new methods to produce HSCs, or other types of blood cells, from human embryonic stem cells or induced pluripotent stem cells. Additionally, as most key transcription factors regulating early hematopoietic development have also been implicated in various types of leukemia, understanding their function during normal development could result in a better comprehension of their roles during abnormal hematopoiesis in leukemia. In this review, we discuss our current understanding of the molecular and cellular mechanisms of blood development from the earliest hematopoietic precursor, the hemangioblast, a precursor for both endothelial and hematopoietic cell lineages.
    • Blood-brain barrier permeability of normal-appearing white matter in patients with vestibular schwannoma: a new hybrid approach for analysis of T1 -W DCE-MRI.

      Li, Ka-Loh; Zhu, Xiaoping; Zhao, Sha; Jackson, Alan; Division of Informatics, Imaging and Data Sciences, University of Manchester, Manchester, UK (2017-07)
      To develop and assess a "hybrid" method that combines a first-pass analytical approach and the Patlak plot (PP) to improve assessment of low blood-brain barrier permeability from dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data.
    • Body mass index and cancer mortality in patients with incident type 2 diabetes: a population-based study of adults in England

      Alam, N. N.; Wright, A. K.; Rutter, M. K.; Buchan, I.; Ashcroft, D. M.; Sperrin, M.; Renehan, Andrew G; Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester (2021)
    • Bone marrow culture studies in refractory cytopenia and 'smouldering leukaemia'.

      Milner, G; Testa, Nydia G; Geary, C G; Dexter, T Michael; Muldal, S; MacIver, J; Lajtha, L G (1977-02)
      As an adjunct to conventional haematological and cytogenetic data, 22 cases of refractory cytopenia, and five with chronic myelomonocytic leukaemia, (CMML) were studied by bone marrow culture. Cultures from II such patients without an excess of marrow myeloblasts usually showed low, or undetectable, numbers of cells capable of giving rise to colonies of granulocytes and/or macrophages (CFUc) but near-normal numbers of cluster-forming cells and cells capable of forming erythroid colonies (CFUE). Those with similar blood pictures, but in whom the marrow contained a slight excess of myeloblasts (II cases), showed a more profound defect in growth patterns: low or undetectable numbers of CFUC, clusters and CFUE, results similar to those found in acute myeloblastic leukaemia, into which three of this group evolved. The patients with CMML gave comparatively normal CFUC, cluster and CFUE growth patterns.
    • Bone marrow toxicity in mice treated with indium-114m-labelled blood cells.

      Hoyes, Katherine P; Wadeson, P J; Murby, Brian; Sharma, Harbans L; Cowan, Richard A; Lord, Brian I; CRC Dept. of Experimental Haematology, Paterson Institute for Cancer Research, University of Manchester, UK. (2001-12)
      Clinical trials with autologous indium-114m-labelled lymphocytes have revealed significant anti-tumour effects in chronic lymphocytic leukaemia patients with highly resistant disease. Substitution of the lymphocyte vector with heat-damaged red blood cells (HDRBC) may make this treatment more universally applicable and reduce the dose-limiting myelosuppression encountered with labelled lymphocytes. Therefore, the bone marrow localization and toxicities of indium-labelled lymphocytes or HDRBC have been investigated in BDFI mice. At 24 hours approximately 4% and 1.2% of 114In(m) administered as labelled lymphocytes or HDRBC respectively was localized within the bone marrow and remained constant for 57 days thereafter. Toxicity towards bone marrow stem cells, measured as CFU-S, was equivalent for both cellular vectors. However, at clinically relevant activities, 114In(m) HDRBC were less toxic than labelled lymphocytes towards committed progenitors, assayed as in vitro-CFC and CFU-Meg. These data suggest that substitution of HDRBC for lymphocytes as the 114In(m) vector may be beneficial in reducing the myelosuppression associated with this technique.
    • Both stromal cell and colonocyte epidermal growth factor receptors control HCT116 colon cancer cell growth in tumor xenografts.

      Mustafi, R; Dougherty, U; Shah, H; Dehghan, H; Gliksberg, A; Wu, J; Zhu, H; Joseph, L; Hart, J; Dive, Caroline; et al. (2012-10)
      Colon cancer growth requires growth-promoting interactions between malignant colonocytes and stromal cells. Epidermal growth factor receptors (EGFR) are expressed on colonocytes and many stromal cells. Furthermore, EGFR is required for efficient tumorigenesis in experimental colon cancer models. To dissect the cell-specific role of EGFR, we manipulated receptor function on stromal cells and cancer cells. To assess the role of stromal EGFR, HCT116 human colon cancer cells were implanted into immunodeficient mice expressing dominant negative (DN) Egfr(Velvet/+) or Egfr(+/+). To assess the role of cancer cell EGFR, HCT116 transfectants expressing inducible DN-Egfr were implanted into immunodeficient mice. To dissect EGFR signals in vitro, we examined colon cancer cells in monoculture or in cocultures with fibroblasts for EGFR transactivation and prostaglandin synthase 2 (PTGS2) induction. EGFR signals were determined by blotting, immunostaining and real-time PCR. Tumor xenografts in Egfr(Velvet/+) mice were significantly smaller than tumors in Egfr(+/+) mice, with decreased proliferation (Ki67) and increased apoptosis (cleaved caspase-3) in cancer cells and decreased stromal blood vessels. Mouse stromal transforming growth factor alpha (TGFA), amphiregulin (AREG), PTGS2 and Il1b and interleukin-1 receptor 1 (Il1r1) transcripts and cancer cell beta catenin (CTNNB1) and cyclin D1 (CCND1) were significantly lower in tumors obtained from Egfr(Velvet/+) mice. DN-EGFR HCT116 transfectants also formed significantly smaller tumors with reduced mouse Areg, Ptgs2, Il1b and Il1r1 transcripts. Coculture increased Caco-2 phospho-active ERBB (pERBB2), whereas DN-EGFR in Caco-2 cells suppressed fibroblast PTGS2 and prostaglandin E2 (PGE2). In monoculture, interleukin 1 beta (IL1B) transactivated EGFR in HCT116 cells. Stromal cell and colonocyte EGFRs are required for robust EGFR signals and efficient tumor growth, which involve EGFR-interleukin-1 crosstalk.
    • Bovine retinal angiogenesis factor is a small molecule (molecular mass less than 600).

      Elstow, S; Schor, Ana M; Weiss, J; Department of Rheumatology, Medical School, University of Manchester, Oxford Road, Manchester M13 9PT, England. (1985-01)
      Two methods were used to extract angiogenic activity from bovine retina. Both methods initially gave rise to nondialyzable (greater than 10,000 Mr) fractions with angiogenic activity. However, after anion exchange chromatography, 20% of the extracts from one of the two methods (method 2) contained a small molecule with angiogenic activity (Mr 300-600). Alcohol treatment of high molecular mass fractions from both methods also released a low molecular mass angiogenic factor (Mr 300-600). No angiogenic activity was left in the nondialyzable residue. The high molecular mass angiogenic fraction obtained by method 1 after DEAE-cellulose chromatography contained a protein immunologically and electrophoretically identical to bovine serum albumin. The low molecular mass retinal angiogenic factor was able to stimulate microvessel endothelial cell proliferation as well as being positive in the chick chorioallantoic membrane test. The presence of a protein carrier system for a small angiogenesis factor is proposed. This would explain discrepancies in the apparent molecular mass of retinal angiogenic factors described previously.
    • Bracken (Pteridium aquilinum)-induced DNA adducts in mouse tissues are different from the adduct induced by the activated form of the Bracken carcinogen ptaquiloside.

      Freitas, R N; O'Connor, Peter J; Prakash, A S; Shahin, M; Povey, Andrew C; Cancer Research Campaign Carcinogenesis Group, Paterson Institute for Cancer Research, Manchester M20 9BX, United Kingdom. (2001-02-23)
      Following treatment with bracken fern (Pteridium aquilinum) extract and bracken spores a number of DNA adducts were detected by (32)P-postlabeling. Three of these adducts have been described previously (Povey et al., Br. J. Cancer (1996) 74, 1342-1348) and in this study, using a slightly different protocol, four new adducts, with higher chromatographic mobility, were detected at levels ranging from 50 to 230% of those previously described. When DNA was treated in vitro with activated ptaquiloside (APT) and analysed by butanol extraction or nuclease P1 treatment, only one adduct was detected by (32)P-postlabeling. This adduct was not present in the DNA from mice treated with bracken fern or spores, suggesting either that bracken contains genotoxins other than ptaquiloside or that the metabolism of ptaquiloside produces genotoxins not reflected by activated ptaquiloside. However, as the ATP-derived adduct has been detected previously in ileal DNA of bracken-fed calves, species-specific differences in the metabolism of bracken genotoxins may exist, thereby leading to differences in their biological outcomes.