1
|
Cahill ME, Walker DM, Gancarz AM, Wang ZJ, Lardner CK, Bagot RC, Neve RL, Dietz DM, Nestler EJ. The dendritic spine morphogenic effects of repeated cocaine use occur through the regulation of serum response factor signaling. Mol Psychiatry 2018; 23:1474-1486. [PMID: 28555077 PMCID: PMC5709273 DOI: 10.1038/mp.2017.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/23/2017] [Accepted: 04/12/2017] [Indexed: 12/28/2022]
Abstract
The nucleus accumbens (NAc) is a primary brain reward region composed predominantly of medium spiny neurons (MSNs). In response to early withdrawal from repeated cocaine administration, de novo dendritic spine formation occurs in NAc MSNs. Much evidence indicates that this new spine formation facilitates the rewarding properties of cocaine. Early withdrawal from repeated cocaine also produces dramatic alterations in the transcriptome of NAc MSNs, but how such alterations influence cocaine's effects on dendritic spine formation remain unclear. Studies in non-neuronal cells indicate that actin cytoskeletal regulatory pathways in nuclei have a direct role in the regulation of gene transcription in part by controlling the access of co-activators to their transcription factor partners. In particular, actin state dictates the interaction between the serum response factor (SRF) transcription factor and one of its principal co-activators, MAL. Here we show that cocaine induces alterations in nuclear F-actin signaling pathways in the NAc with associated changes in the nuclear subcellular localization of SRF and MAL. Using in vivo optogenetics, the brain region-specific inputs to the NAc that mediate these nuclear changes are investigated. Finally, we demonstrate that regulated SRF expression, in turn, is critical for the effects of cocaine on dendritic spine formation and for cocaine-mediated behavioral sensitization. Collectively, these findings reveal a mechanism by which nuclear-based changes influence the structure of NAc MSNs in response to cocaine.
Collapse
Affiliation(s)
- ME Cahill
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - DM Walker
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - AM Gancarz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - ZJ Wang
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - CK Lardner
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - RC Bagot
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA,Department of Psychology, McGill University, Montréal, QC, Canada
| | - RL Neve
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - DM Dietz
- Department of Pharmacology and Toxicology, Research Institute on Addictions, Program in Neuroscience, State University at Buffalo, Buffalo, NY, USA
| | - EJ Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| |
Collapse
|
2
|
Gehrmann-De Ridder A, Gehrmann T, Glover EWN, Huss A, Walker DM. Next-to-Next-to-Leading-Order QCD Corrections to the Transverse Momentum Distribution of Weak Gauge Bosons. Phys Rev Lett 2018; 120:122001. [PMID: 29694069 DOI: 10.1103/physrevlett.120.122001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Indexed: 06/08/2023]
Abstract
The transverse momentum spectra of weak gauge bosons and their ratios probe the underlying dynamics and are crucial in testing our understanding of the standard model. They are an essential ingredient in precision measurements, such as the W boson mass extraction. To fully exploit the potential of the LHC data, we compute the second-order [next-to-next-to-leading-order (NNLO)] QCD corrections to the inclusive-p_{T}^{W} spectrum as well as to the ratios of spectra for W^{-}/W^{+} and Z/W. We find that the inclusion of NNLO QCD corrections considerably improves the theoretical description of the experimental CMS data and results in a substantial reduction of the residual scale uncertainties.
Collapse
Affiliation(s)
- A Gehrmann-De Ridder
- Institute for Theoretical Physics, ETH, CH-8093 Zürich, Switzerland
- Department of Physics, University of Zürich, CH-8057 Zürich, Switzerland
| | - T Gehrmann
- Department of Physics, University of Zürich, CH-8057 Zürich, Switzerland
| | - E W N Glover
- Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE, United Kingdom
| | - A Huss
- Theoretical Physics Department, CERN, 1211 Geneva 23, Switzerland
| | - D M Walker
- Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE, United Kingdom
| |
Collapse
|
3
|
Walker DM, Gale CP, Lip G, Martin-Sanchez FJ, McIntyre HF, Mueller C, Price S, Sanchis J, Vidan MT, Wilkinson C, Zeymer U, Bueno H. Editor's Choice - Frailty and the management of patients with acute cardiovascular disease: A position paper from the Acute Cardiovascular Care Association. Eur Heart J Acute Cardiovasc Care 2018; 7:176-193. [PMID: 29451402 DOI: 10.1177/2048872618758931] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Frailty is increasingly seen among patients with acute cardiovascular disease. A combination of an ageing population, improved disease survival, treatable long-term conditions as well as a greater recognition of the syndrome has accelerated the prevalence of frailty in the modern world. Yet, this has not been matched by an expansion of research. National and international bodies have identified acute cardiovascular disease in the frail as a priority area for care and an entity that requires careful clinical decisions, but there remains a paucity of guidance on treatment efficacy and safety, and how to manage this complex group. This position paper from the Acute Cardiovascular Care Association presents the latest evidence about frailty and the management of frail patients with acute cardiovascular disease, and suggests avenues for future research.
Collapse
Affiliation(s)
| | - C P Gale
- 2 Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK
| | - G Lip
- 3 Institute for Cardiovascular Sciences, University of Birmingham, UK.,4 Aalborg Thrombosis Research Unit, Aalborg University, Denmark
| | | | | | - C Mueller
- 6 Cardiovascular Research Institute Basel, University of Basel, Switzerland
| | - S Price
- 7 Royal Brompton Hospital, UK
| | - J Sanchis
- 8 Department of Cardiology, University of Valencia, Spain.,9 University of Valencia, CIBER CV, Spain
| | - M T Vidan
- 10 Department of Geriatrics, Universidad Complutense de Madrid Dr Esquerdo, Spain
| | - C Wilkinson
- 2 Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, UK
| | - U Zeymer
- 11 Klinikum Ludwigshafen und Institut for Herzinfarktforschung, Germany
| | - H Bueno
- 12 National Centre for Cardiovascular Research, Spain
| |
Collapse
|
4
|
Affiliation(s)
- R Amin
- Senior House Officer, Department of Cardiology, Conquest Hospital, St. Leonards-on-Sea, East Sussex
| | - Dzj Lee
- Specialty Registrar, Department of Cardiology, Conquest Hospital, St. Leonards-on-Sea, East Sussex TN37 7RD
| | - C F Camm
- Senior House Officer, Department of Cardiology, Conquest Hospital, St. Leonards-on-Sea, East Sussex
| | - D M Walker
- Consultant Cardiologist, Department of Cardiology, Conquest Hospital, St. Leonards-on-Sea, East Sussex
| |
Collapse
|
5
|
Affiliation(s)
- D M Walker
- Department of Oral Medicine, Dental School, Welsh National School of Medicine, Heath Park, Cardiff, CF4 4XY
| |
Collapse
|
6
|
Khalifa N, Talbot E, Schneider J, Walker DM, Bates P, Bird Y, Davies D, Brookes C, Hall J, Völlm B. Individual placement and support (IPS) for patients with offending histories: the IPSOH feasibility cluster randomised trial protocol. BMJ Open 2016; 6:e012710. [PMID: 27449894 PMCID: PMC4964185 DOI: 10.1136/bmjopen-2016-012710] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION People with involvement in forensic psychiatric services face many obstacles to employment, arising from their offending, as well as their mental health problems. This study aims to assess the feasibility of conducting a randomised controlled trial (RCT) to evaluate the effectiveness of individual placement and support (IPS), in improving employment rates and associated psychosocial outcomes in forensic psychiatric populations. IPS has been found consistently to achieve employment rates above 50% in psychiatric patients without a history of involvement in criminal justice services. METHODS/DESIGN This is a single-centre feasibility cluster RCT. Clusters will be defined according to clinical services in the community forensic services of Nottinghamshire Healthcare NHS Foundation Trust (NHCT). IPS will be implemented into 2 of the randomly assigned intervention clusters in the community forensic services of NHCT. A feasibility cluster RCT will estimate the parameters required to design a full RCT. The primary outcome is the proportion of people in open employment at 12-month follow-up. Secondary outcome measures will include employment, educational activities, psychosocial and economic outcomes, as well as reoffending rates. Outcome measures will be recorded at baseline, 6 months and 12 months. In accordance with the UK Medical Research Council guidelines on the evaluation of complex interventions, a process evaluation will be carried out; qualitative interviews with patients and staff will explore general views of IPS as well as barriers and facilitators to implementation. Fidelity reviews will assess the extent to which the services follow the principles of IPS prior, during and at the end of the trial. ETHICS AND DISSEMINATION Ethical approval was obtained from the East Midlands Research Ethics Committee-Nottingham 1 (REC reference number 15/EM/0253). Final and interim reports will be prepared for project funders, the study sponsor and clinical research network. Findings will be disseminated through peer-reviewed journals, conferences and event presentations. TRIAL REGISTRATION NUMBER NCT02442193; Pre-results.
Collapse
Affiliation(s)
- N Khalifa
- Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
- University of Nottingham, Nottingham, UK
- Institute of Mental Health, Nottingham, UK
| | - E Talbot
- Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
| | - J Schneider
- University of Nottingham, Nottingham, UK
- Institute of Mental Health, Nottingham, UK
| | - D M Walker
- Faculty of Health Sciences, University of Southampton, Southampton, UK
| | - P Bates
- Patient and Public Involvement Lead, Nottingham, UK
| | - Y Bird
- Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
| | - D Davies
- Leicestershire and Rutland Probation Trust, Leicestershire, UK
| | - C Brookes
- Leicester Clinical Trials Unit, University of Leicester, Leicester, UK
| | - J Hall
- Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
| | - B Völlm
- Nottinghamshire Healthcare NHS Foundation Trust, Nottingham, UK
- University of Nottingham, Nottingham, UK
- Institute of Mental Health, Nottingham, UK
| |
Collapse
|
7
|
West NEJ, Walker DM, Ray SG, Weston C, Quinn T, Birkhead JS. 021 IS THERE A NEED FOR SPECIALIST CARDIAC CARE FOR PATIENTS WITH NON-ST ELEVATION MYOCARDIAL INFARCTION? AN ANALYSIS OF 85 780 PATIENT EPISODES FROM THE MINAP DATABASE 2008–2009:. Heart 2013. [DOI: 10.1136/heartjnl-2013-304019.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
8
|
Chung TTLL, Drake WM, Plowman PN, Metcalfe K, Grossman AB, Akker SA, Chew SL, Besser GM, Walker DM, Koltowska-Haggstrom M, Wilton P, Mattsson AF, Monson JP. No clear evidence for an association between GH replacement and relapse of intracranial germ cell tumours: single centre and KIMS experience. Eur J Endocrinol 2010; 163:357-8. [PMID: 20516207 DOI: 10.1530/eje-10-0498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
9
|
Moyes VJ, Walker DM, Owusu-Antwi S, Maher KT, Metherell L, Akker SA, Monson JP, Clark AJL, Drake WM. d3-GHR genotype does not explain heterogeneity in GH responsiveness in hypopituitary adults. Clin Endocrinol (Oxf) 2010; 72:807-13. [PMID: 20039885 DOI: 10.1111/j.1365-2265.2009.03768.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Heterogeneity in growth hormone (GH) responsiveness in adult hypopituitary patients receiving recombinant human GH (rhGH) is poorly understood; doses vary up to fourfold between individuals. Deletion of exon 3 in the GH receptor (d3-GHR) has been linked to enhanced rhGH responsiveness in children. We investigated the role of the d3-GHR polymorphism in determining adult rhGH responsiveness. METHODS One hundred and ninety-four patients treated with an identical rhGH dosing protocol in a single centre were genotyped for the d3-GHR, and the results correlated with changes in serum IGF-I and clinical parameters of GH responsiveness after 6 and 12 months of GH replacement therapy. RESULTS Allele frequencies for homozygous full length (fl/fl), heterozygous d3 (fl/d3) and homozygous d3 (d3/d3) were 52%, 38.7% and 9.3%, respectively, and were in Hardy-Weinberg equilibrium. Baseline IGF-I and DeltaIGF-I at 6 months were comparable between groups. DeltaIGF-I at 12 months was significantly greater in the d3/d3 group (P = 0.028). No difference was detected between fl/d3 and fl/fl groups. Regression analyses of DeltaIGF-I at 12 months and DeltaIGF-I/rhGH dose confirmed a significant relationship of d3/d3 genotype on rhGH response. There was no difference between groups in maintenance rhGH dose between genotypes. CONCLUSION Homozygosity for d3-GHR confers a marginal increase in GH responsiveness at 12 months but without a detectable change in maintenance rhGH dose required. Both d3 alleles are required to achieve this response; given that only 10% of the population are d3 homozygotes, the d3GHR does not explain the marked heterogeneity of GH responsiveness in hypopituitary adults.
Collapse
Affiliation(s)
- V J Moyes
- Department of Endocrinology, St. Bartholomew's Hospital, London, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Mehta PA, Dubrey SW, McIntyre HF, Walker DM, Hardman SMC, Sutton GC, McDonagh TA, Cowie MR. Improving survival in the 6 months after diagnosis of heart failure in the past decade: population-based data from the UK. Heart 2009; 95:1851-6. [PMID: 19587390 DOI: 10.1136/hrt.2008.156034] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To investigate the secular trend in survival after a new diagnosis of heart failure in the UK population. DESIGN AND SETTING Comparison of all-cause mortality in the 6 months after diagnosis of heart failure in population-based studies in the south east of England in 2004-5 (Hillingdon-Hastings Study) and 1995-7 (Hillingdon-Bromley Studies). PARTICIPANTS 396 patients in the 2004-5 cohort and 552 patients in the 1995-7 cohort with incident (new) heart failure. MAIN OUTCOME MEASURES All-cause mortality. RESULTS All-cause mortality rates were 6% (95% CI 3% to 8%) at 1 month, 11% (8% to 14%) at 3 months and 14% (11% to 18%) at 6 months in the 2004-5 cohort compared with 16% (13% to 20%), 22% (19% to 25%) and 26% (22% to 29%), respectively, in the 1995-7 cohort (difference between the two cohorts, p<0.001). The difference in survival was not explained by any difference in the demographics or severity of heart failure at presentation. There was a difference at baseline and thereafter in the use of neurohormonal antagonists (beta-blockers and angiotensin-converting enzyme inhibitors). CONCLUSIONS Although early mortality remains high among patients with newly diagnosed heart failure in the UK general population, there is strong evidence of a marked improvement in survival from 1995-7 to 2004-5, perhaps partly explained by an increased usage of neurohormonal antagonists.
Collapse
|
11
|
Affiliation(s)
- M Z Khawaja
- Department of Cardiology, Conquest Hospital Hastings TN37 7RD, UK
| | | |
Collapse
|
12
|
Kalavrezos N, Baldwin DJ, Walker DM. Giant neglected ameloblastoma: single stage treatment and clinicopathological review. Br J Oral Maxillofac Surg 2008; 46:591-3. [DOI: 10.1016/j.bjoms.2008.02.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2008] [Indexed: 11/30/2022]
|
13
|
Eamens GJ, Walker DM, Porter NS, Fell SA. Radiometric pooled faecal culture for the detection ofMycobacterium aviumsubspparatuberculosisin low-shedder cattle. Aust Vet J 2008; 86:259-65. [DOI: 10.1111/j.1751-0813.2008.00313.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
14
|
Abstract
OBJECTIVE To evaluate pooled faecal culture for herd diagnosis of caprine Johne's disease and relate these findings to faecal shedding rates of Mycobacterium avium subsp paratuberculosis (Map). DESIGN Radiometric broth culture was applied to several pooling dilutions, and shedding rates were estimated from a regression equation based on bacterial growth rates and known processing losses during radiometric culture. PROCEDURE Sixteen faecal samples from goats naturally infected with sheep (n = 3) or cattle (n = 13) strains of Map, were diluted in normal goat faeces from 1 in 5 to 1 in 50. Cultures were confirmed by IS900 polymerase chain reaction and restriction endonuclease analysis, and mycobactin dependency. The numbers of viable Map in the culture inocula were determined by endpoint titration (most probable number) of nine samples and related to a cumulative growth index. RESULTS A pooling dilution of 1 in 25 with an incubation period of 10 weeks detected 13 of 16 culture positive goats, all shedding > or = 2 x 10(4) Map per gram of faeces. Two samples containing very low numbers of Map (< 2 x 10(3)/g) were only culture positive from undiluted faeces. Thirteen of 16 goats were considered to be shedding low to moderate concentrations of Map (< 2 x 10(5)/g faeces). CONCLUSIONS These data support a pooling dilution of 1 in 25 for application of pooled faecal culture as a diagnostic tool in caprine Johne's disease control. A test based on this dilution would reduce laboratory costs of whole herd testing in goats by approximately 40% relative to serology and 75 to 90% relative to individual faecal culture.
Collapse
Affiliation(s)
- G J Eamens
- New South Wales Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Camden, NSW 2570.
| | | | | | | |
Collapse
|
15
|
Arora M, Kennedy BJ, Ryan CG, Boadle RA, Walker DM, Harland CL, Lai B, Cai Z, Vogt S, Zoellner H, Chan SWY. The application of synchrotron radiation induced X-ray emission in the measurement of zinc and lead in Wistar rat ameloblasts. Arch Oral Biol 2007; 52:938-44. [PMID: 17521603 DOI: 10.1016/j.archoralbio.2007.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 04/04/2007] [Accepted: 04/06/2007] [Indexed: 12/31/2022]
Abstract
The development of analytical techniques for the measurement of trace elements in cellular compartments of developing teeth remains an important methodological issue in dental research. Recent advances in third generation synchrotron facilities have provided high brilliance X-ray sources that can be effectively used to study trace element distributions in small spatial regions with low detection limits. The present study describes for the first time the application of synchrotron radiation induced X-ray emission (SRIXE) in measuring the distribution of zinc and lead in the ameloblasts of developing Wistar rat teeth. Wistar rats were fed a standard rat diet, containing the normal dietary requirements of zinc, ad libitum and exposed to 100 ppm of lead in drinking water. Resin embedded sections of first mandibular molars were analysed using a 13.3 keV incident monochromatic X-ray beam focussed to a 0.2 microm spot. Characteristic X-rays arising from the entire thickness of the sample were measured using an energy dispersive detector for quantitative analysis of elemental concentrations. The results showed that intranuclear concentrations of zinc were greater than levels in the cytoplasm. Furthermore, nuclear and cytoplasmic concentrations of zinc in the maturation stage (742+/-27 and 424+/-25 ppm, respectively) were significantly higher than the zinc levels observed in the nucleus and cytoplasm of presecretory stage ameloblasts (132+/-10 and 109+/-10 ppm, respectively) (p<0.05). A clear lead signal above the background was not detected in the ameloblasts and lead concentrations could only be reliably measured in the developing enamel. Overall, SRIXE was an effective method of studying the spatial distribution of zinc in the cells of developing teeth and offered a unique combination of sub-micron spatial resolution and parts-per-million detection limits (0.8-1 and 0.6-1 ppm for zinc and lead, respectively).
Collapse
Affiliation(s)
- Manish Arora
- Cellular and Molecular Pathology Research Unit, Department of Oral Pathology, Faculty of Dentistry, University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Arora M, Kennedy BJ, Elhlou S, Pearson NJ, Walker DM, Bayl P, Chan SWY. Spatial distribution of lead in human primary teeth as a biomarker of pre- and neonatal lead exposure. Sci Total Environ 2006; 371:55-62. [PMID: 16950500 DOI: 10.1016/j.scitotenv.2006.07.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 07/19/2006] [Accepted: 07/20/2006] [Indexed: 05/11/2023]
Abstract
Lead remains one of the most hazardous toxins in our environment. Because the toxic effects of lead are most prominent during early development, it is important to develop a suitable biomarker for lead exposure during the pre- and neonatal periods. In the present study, the spatial distribution of lead was measured in the enamel and dentine of ten human primary teeth using laser ablation-inductively coupled plasma-mass spectrometry. The neonatal line, visualized using confocal laser scanning microscopy, was used to demarcate the pre- and postnatal regions of the sample teeth. Lead levels in pre- and postnatally formed enamel and dentine were compared to blood-lead levels measured at birth and one year of age for four of these participants. Mean dentine-lead levels ranged from 0.17+/-0.02 to 5.60+/-1.79 microg/g, and mean enamel-lead levels ranged from 0.04+/-0.01 to 1.47+/-0.20 microg/g. The results of this preliminary study showed that the spatial distribution of lead in dentine reflected the blood-lead levels. The present study demonstrates a methodology where the spatial distribution of lead in the dentine of human primary teeth may be used to obtain temporal information of environmental lead exposure during the pre- and neonatal periods.
Collapse
Affiliation(s)
- Manish Arora
- Cellular and Molecular Pathology Research Unit, Department of Oral Pathology, University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia.
| | | | | | | | | | | | | |
Collapse
|
17
|
|
18
|
Curtis NJ, Walker DM. A case of aggressive multiple metachronous central giant cell granulomas of the jaws: differential diagnosis and management options. Int J Oral Maxillofac Surg 2005; 34:806-8. [PMID: 16157251 DOI: 10.1016/j.ijom.2005.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2003] [Revised: 10/08/2004] [Accepted: 01/25/2005] [Indexed: 11/16/2022]
Abstract
We describe multiple metachronous central giant cell granulomas in a 62-year-old man who has a first degree relative with a history of a solitary central giant cell granulomas. The patient presented in 1997 with a large central giant cell granuloma of the right maxilla which was treated with a partial maxillectomy. A small recurrence was then identified and the successful management of this is described. The patient has also a histologically confirmed central giant cell granuloma previously removed from the right body of the mandible and the left angle of the mandible. The differential diagnosis of multiple central giant cell granulomas of the jaw is considered. It is possible that the present case may indeed represent a new syndrome or subtype of multiple central giant cell granulomas. The problem of treating such aggressive sub-types of giant cell granulomas is also addressed in the context of recent advances of surgical and medical management.
Collapse
|
19
|
Abstract
A 54-year-old man presented with a painful left proptosis and a soft tissue mass at the inferolateral aspect of the left orbit with bone involvement. There was no clinical or investigational evidence of systemic disease. Both light microscopy and immunohistochemistry were required for the diagnosis of Ewing sarcoma. After failure of chemotherapy alone, management included extensive surgical excision and postoperative adjuvant radiotherapy and chemotherapy. Despite intervention, the patient died of widespread metastatic disease 17 months after initial presentation. Although rare, Ewing sarcoma should be included in the differential diagnosis of uniform round cell orbital tumors in adults.
Collapse
|
20
|
|
21
|
Arora M, Chan SWY, Ryan CG, Kennedy BJ, Walker DM. Spatial distribution of lead in enamel and coronal dentine of wistar rats. Biol Trace Elem Res 2005; 105:159-70. [PMID: 16034161 DOI: 10.1385/bter:105:1-3:159] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 10/18/2004] [Accepted: 10/25/2004] [Indexed: 11/11/2022]
Abstract
Lead is one of the most hazardous environmental toxins known. The assessment of lead in dental hard tissues is important in the understanding of its toxic effects on oral tissues and in estimating exposure and body burden in individuals exposed to lead from the environment. However, current information on the uptake and distribution of lead in enamel and dentine is limited. The aim of this project was to study, at high resolution, the spatial distribution of lead in enamel and coronal dentine using an experimental rat model. A dose of 40 mg/L of lead nitrate was administered to pregnant female rats during the periods of gestation and lactation through drinking water. First mandibular molar teeth were removed from their 15-d-old pups and the distribution of lead was studied using a nuclear microprobe (NMP). The distribution of lead in enamel and coronal dentine showed four distinct zones with significantly different mean lead concentrations (p<0.05). High levels of lead were observed in the superficial regions of enamel and in the dentine directly adjacent to the pulp. Additionally, the results confirmed that the NMP is capable of mapping the distribution of lead in teeth at micron resolutions with a detection limit of approx 1 microg/g.
Collapse
Affiliation(s)
- Manish Arora
- Oral Pathology and Oral Medicine, Faculty of Dentistry, University of Sydney, Level 2, Westmead Centre for Oral Health, Westmead Hospital, Wentworthville, NSW 2145 Australia
| | | | | | | | | |
Collapse
|
22
|
Georgiou AF, Walker DM, Collins AP, Morgan GJ, Shannon JA, Veness MJ. Primary small cell undifferentiated (neuroendocrine) carcinoma of the maxillary sinus. ACTA ACUST UNITED AC 2004; 98:572-8. [PMID: 15529129 DOI: 10.1016/j.tripleo.2004.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Primary small cell undifferentiated (neuroendocrine) carcinomas of the paranasal sinuses are extremely uncommon neoplasms. This tumor was first reported in this site in 1965, and since then there have been only 61 documented cases in the literature. The median age at presentation is 53 years, with no gender predilection. There is no reported association of occurrence of this tumor with either tobacco use or form of occupation, and case outcome is usually poor. We report a case in a 25-year-old man, initially treated as an odontogenic infection and thus delaying institution of appropriate management. Further investigation identified a locally advanced neuroendocrine carcinoma of the left maxilla. Despite radiotherapy and chemotherapy, the patient exhibited rapid tumor dissemination and died.
Collapse
Affiliation(s)
- Anastasia F Georgiou
- Department of Oral Medical Surgical Sciences, Westmead Centre for Oral Health, Westmead, New South Wales, Australia.
| | | | | | | | | | | |
Collapse
|
23
|
Walker DM. Oral mucosal immunology: an overview. Ann Acad Med Singap 2004; 33:27-30. [PMID: 15389303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
The primary function of the immune system of the mouth is to protect the teeth, jaws, gingivae and oral mucosa against infection. These host defences vary in the different oral microenvironments or domains represented by the oral mucosa, saliva and gingival crevice. This review aims to consider and contrast the main immune components in each domain and cites examples of oral diseases where the immune response is defective.
Collapse
Affiliation(s)
- D M Walker
- Oral Pathology & Oral Medicine, Westmead Centre for Oral Health, Westmead Hospital, Wentworthville, Australia
| |
Collapse
|
24
|
Abstract
Oral cancer is a serious public health problem, with over 200,000 new cases reported annually worldwide, two-thirds of which occur in developing countries. The overall mortality rate for intra-oral cancer remains high at approximately 50%, even with modern medical services, probably due to the advanced stage of the disease at presentation. This review outlines recent advances in our understanding of the roles and interactions of major risk factors for oral cancer worldwide, notably tobacco, alcohol and betel quid and the genetic polymorphisms determining their metabolism that may predispose patients to oral carcinoma. Oral epithelial lesions with malignant potential are described. We discuss the histopathology of oral cancer, its grading and the staging of the disease at clinical, microscopic, immunohistological and molecular levels. A recommended minimum dataset for pathology reports is described. The available strategies and current prospects for controlling oral cancer in the community are summarised.
Collapse
Affiliation(s)
- D Murray Walker
- Oral Pathology & Oral Medicine, University of Sydney and Anatomical Pathology, ICPMR Westmead Hospital, Westmead, NSW, Australia.
| | | | | |
Collapse
|
25
|
Abstract
Lead remains one of the most hazardous metals in our environment. The concentrations of lead in coronal dentine and enamel have previously been reported but limited information is available regarding lead levels in radicular dentine and cementum. This study reports the distribution of lead in 26 roots of 16 human maxillary primary teeth from seven individuals. In addition, calcium and phosphorous concentrations were also measured to detect any variations in the degree of mineralization in different regions of the roots. The mean lead concentration in these roots was 1.67 +/- 1.43 microg/g, which is comparable to other studies. In all cases there were higher lead concentrations in the apices of non-resorbed roots of primary maxillary teeth relative to middle and cervical regions. The findings reported here are of potential significance during the process of physiological root resorption whence periapical tissue may be exposed to higher levels of lead.
Collapse
Affiliation(s)
- Manish Arora
- Oral Pathology and Oral Medicine, Faculty of Dentistry, Westmead Centre for Oral Health, Westmead Hospital, University of Sydney, Wentworthville, NSW, Australia.
| | | | | | | | | | | |
Collapse
|
26
|
Li W, Thompson CH, O'Brien CJ, McNeil EB, Scolyer RA, Cossart YE, Veness MJ, Walker DM, Morgan GJ, Rose BR. Human papillomavirus positivity predicts favourable outcome for squamous carcinoma of the tonsil. Int J Cancer 2003; 106:553-558. [PMID: 12845651 DOI: 10.1002/ijc.11261] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Mutations in the p53 and retinoblastoma (pRb) pathways associated with the use of tobacco and alcohol are common in squamous cell carcinoma (SCC) of the head and neck. Cell cycle proteins are also affected by human papillomavirus (HPV), which may also have an aetiological role in cancers at particular sites, most notably the tonsil. Attempts to identify prognostic molecular markers in head and neck cancers have met with conflicting results, but few studies have been undertaken with tumours of known HPV status at a single anatomic site. In our study 86 tonsil cancers were analysed for HPV status by sequence analysis of polymerase chain reaction products and for the expression of cell cycle proteins (p53, p21(CIP1/WAF1), pRb, p16(INK4A), cyclin D1 and p27(KIP1)) by immunohistochemistry. The HPV status could be established in 67 of the tumours. Thirty-one (46%) of these were HPV-positive, predominantly (28/31) for HPV16. Findings were related to tumour recurrence and patient survival. None of the cell cycle proteins independently predicted recurrence or survival. Patients with HPV-positive tumours, however, were significantly less likely (p < 0.05) to have recurrence or to die of disease than those with HPV-negative tumours, after adjusting for the effects of the cell cycle proteins, clinical stage, pathological node status, tumour grade, age, gender and treatment. These findings support the concept that HPV-positive tonsil cancers may be a distinct biological group with less aggressive characteristics. Screening of tonsil cancers for HPV DNA may help optimise treatment and provide more accurate prognostic information.
Collapse
Affiliation(s)
- Wei Li
- Sydney Head and Neck Cancer Institute, Royal Prince Alfred Hospital, Sydney, Australia
- Department of Infectious Diseases, University of Sydney, Sydney, Australia
| | - Carol H Thompson
- Department of Infectious Diseases, University of Sydney, Sydney, Australia
| | - Christopher J O'Brien
- Sydney Head and Neck Cancer Institute, Royal Prince Alfred Hospital, Sydney, Australia
| | - Edward B McNeil
- Sydney Head and Neck Cancer Institute, Royal Prince Alfred Hospital, Sydney, Australia
| | - Richard A Scolyer
- Department of Anatomical Pathology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Yvonne E Cossart
- Department of Infectious Diseases, University of Sydney, Sydney, Australia
| | - Michael J Veness
- Head and Neck Unit, Westmead Hospital, Sydney, New South Wales, Australia
| | - D Murray Walker
- Department of Oral Pathology, Westmead Hospital, Sydney, New South Wales, Australia
| | - Gary J Morgan
- Head and Neck Unit, Westmead Hospital, Sydney, New South Wales, Australia
| | - Barbara R Rose
- Sydney Head and Neck Cancer Institute, Royal Prince Alfred Hospital, Sydney, Australia
- Department of Infectious Diseases, University of Sydney, Sydney, Australia
| |
Collapse
|
27
|
Abstract
BACKGROUND Debate continues as to whether being young confers a worse prognosis for patients with squamous cell carcinoma of the tongue. Recent papers have provided conflicting views in this debate. In this study we aimed to investigate if young age at the time of diagnosis of squamous cell carcinoma of the tongue confers a worse prognosis. METHODS Eligible patients were identified through the computer database of the Department of Radiation Oncology, Westmead Hospital, Sydney. All eligible patients were treated with radical intent. Using age 40 as a cut off multivariate and survival analysis was undertaken to compare age groups. RESULTS Median age at diagnosis was 60 years (range, 19-86 years) in 84 males (65 per cent) and 45 females (35 per cent). Median follow-up time was 43 months (range, 2.3-203 months). Fifteen patients (12 per cent) were aged <40 years. On univariate analysis stage and age were significant determinants of disease-specific survival. There was no difference in overall survival between the young (<40 years) and middle-aged groups (40-60 years). However, the young and the middle aged were both more likely to survive than the older age group (>60 years). On multivariate analysis age remained a significant factor for determining disease-specific survival, with the older age group 2.9 times more likely to die than the younger groups. CONCLUSION Young age (<40 years) did not portend to worse survival in comparison to older tongue cancer patients.
Collapse
Affiliation(s)
- D M Hyam
- Department of Oral and Maxillofacial Surgery, Westmead Hospital, Sydney
| | | | | | | | | | | | | |
Collapse
|
28
|
McEwen A, Emmanuel C, Medbury H, Leick A, Walker DM, Zoellner H. Induction of contact-dependent endothelial apoptosis by osteosarcoma cells suggests a role for endothelial cell apoptosis in blood-borne metastasis. J Pathol 2003; 201:395-403. [PMID: 14595751 DOI: 10.1002/path.1457] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although tumour cells are believed to migrate between endothelial cells early in metastasis, the possibility remains that endothelial apoptosis may also contribute to the tumour's breach of the vascular barrier. Although seemingly inconsistent with tumour angiogenesis, one publication describes the induction of contact-dependent apoptosis in cultured endothelium by tumour cells. The cell culture data are, however, open to challenge on technical grounds while there are no confirmatory reports. The present paper describes experiments overcoming these limitations. SAOS-2 human osteosarcoma cells and two rat carcinoma cell lines were co-cultured with human umbilical vein endothelial cells (HUVECs) and cultures labelled by surface lectin histochemistry for endothelium. The HUVEC culture density was determined and SAOS-2 cells, but not rat carcinoma cells, were found significantly to reduce HUVEC survival despite the release of potent growth factors as determined in separate experiments with tumour cell conditioned medium. Lectin labelling combined with light microscopy, transmission electron microscopy, flow cytometry for both lectin binding and DNA content, and DNA gel electrophoresis of SAOS-2/HUVEC co-cultures revealed extensive HUVEC apoptosis. These findings indicate contact-dependent endothelial apoptosis by SAOS-2, while this activity appeared weaker and overwhelmed by HUVEC proliferation with rat carcinoma cells. Importantly, this study supports the suggestion that endothelial apoptosis may be important for metastasis and suggests a complex interplay between endothelial proliferation and apoptosis in tumours.
Collapse
Affiliation(s)
- A McEwen
- The Cellular and Molecular Pathology Research Unit, The Department of Oral Medicine and Oral Pathology, Faculty of Dentistry, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia
| | | | | | | | | | | |
Collapse
|
29
|
McIntyre HF, Barrett J, Murphy S, Wray R, Sutcliffe SJ, Walker DM. Across the interface: the hastings heart function clinic. Heart 2002; 88 Suppl 2:ii23-7. [PMID: 12213796 PMCID: PMC1876269 DOI: 10.1136/heart.88.suppl_2.ii23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- H F McIntyre
- The Conquest Hospital, Hastings, East Sussex, UK.
| | | | | | | | | | | |
Collapse
|
30
|
Chan SW, Collins S, Masters CL, Walker DM. Classical and variant Creutzfeldt-Jakob diseases and their potential impact on the practice of clinical dentistry in Australia. Aust Dent J 2001; 46:251-7. [PMID: 11838871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Following recent published evidence regarding the experimental transmission of prion diseases via blood transfusion, dental practitioners have expressed their concern about the potential impact of these transmissible spongiform encephalopathies on dental care provision. This review provides updated information on Creutzfeldt-Jakob disease and related disorders and highlights their potential significance for the practice of clinical dentistry. The current guidelines in Australia relating to infection control and clinical dental procedures are discussed together with recommended guidelines and considerations from the United Kingdom and the World Health Organization (WHO).
Collapse
Affiliation(s)
- S W Chan
- Oral Pathology Unit, Westmead Dental Clinical School, The University of Sydney, NSW
| | | | | | | |
Collapse
|
31
|
Abstract
Inositol lipids play key roles in many fundamental cellular processes that include growth, cell survival, motility, and membrane trafficking. Recent studies on the PTEN and Myotubularin proteins have underscored the importance of inositol lipid 3-phosphatases in cell function. Inactivating mutations in the genes encoding PTEN and Myotubularin are key steps in the progression of some cancers and in the onset of X-linked myotubular myopathy, respectively. Myotubularin-related protein 3 (MTMR3) shows extensive homology to Myotubularin, including the catalytic domain, but additionally possesses a C-terminal extension that includes a FYVE domain. We show that MTMR3 is an inositol lipid 3-phosphatase, with a so-far-unique substrate specificity. It is able to hydrolyze PtdIns3P and PtdIns3,5P2, both in vitro and when heterologously expressed in S. cerevisiae, and to thereby provide the first clearly defined route for the cellular production of PtdIns5P. Overexpression of a catalytically dead MTMR3 (C413S) in mammalian cells induces a striking formation of vacuolar compartments that enclose membranous structures that are highly concentrated in mutant proteins.
Collapse
Affiliation(s)
- D M Walker
- Physiological Laboratory, University of Liverpool, Crown Street, L69 3BX, Liverpool, United Kingdom
| | | | | | | | | | | |
Collapse
|
32
|
Veness MJ, Morgan G, Collins AP, Walker DM. Calcifying epithelial odontogenic (Pindborg) tumor with malignant transformation and metastatic spread. Head Neck 2001; 23:692-6. [PMID: 11443753 DOI: 10.1002/hed.1097] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Pindborg tumors (calcifying epithelial odontogenic tumors) are uncommon neoplasms of odontogenic origin most often located in the posterior mandible. First described in detail in 1955 by Pindborg, these tumors are considered benign but can be locally aggressive in nature, with recurrence rates of 10% to 15% reported. The malignant form of this tumor is exceedingly rare. METHODS We describe the case of a 64-year-old woman initially treated for a painful infected left mandibular third molar. The patient underwent extraction of the tooth and excision of an associated soft tissue component. Subsequent histologic review identified a Pindborg tumor of the left posterior mandible. RESULTS After initial excision, this tumor recurred twice, with the recurrences exhibiting a progression to a malignant Pindborg tumor (odontogenic carcinoma) with vascular invasion and spread to a cervical lymph node. Further treatment involved radical surgery and adjuvant radiotherapy. At last review 12 months after treatment, the patient was disease free. CONCLUSIONS This article describes only the second case of odontogenic carcinoma. The transformation from benign to malignant histologic findings has not previously been documented in this tumor. The salient clinical features of this case are presented along with supportive pathologic and radiologic evidence.
Collapse
Affiliation(s)
- M J Veness
- Department of Radiation Oncology, Westmead Hospital, Westmead, New South Wales, 2145, Sydney, Australia.
| | | | | | | |
Collapse
|
33
|
Meng Q, Henderson RF, Long L, Blair L, Walker DM, Upton PB, Swenberg JA, Walker VE. Mutagenicity at the Hprt locus in T cells of female mice following inhalation exposures to low levels of 1,3-butadiene. Chem Biol Interact 2001; 135-136:343-61. [PMID: 11397400 DOI: 10.1016/s0009-2797(01)00222-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A study was conducted to test the hypothesis that repeated low level exposures to 1,3-butadiene (BD), approaching the OSHA occupational threshold for this chemical, produce a significant mutagenic response in mice. Female B6C3F1 mice (4-5 weeks of age) were exposed by inhalation for 2 weeks (6 h/day, 5 days/week) to 0 or 3 ppm BD, and then necropsied at 4 weeks after the cessation of exposures to measure the frequency of mutations (MF) at the Hprt locus using the T-lymphocyte clonal assay. At necropsy, T cells were isolated from spleen and cultured in the presence of mitogen, growth factors, and a selection agent. Cells were scored for growth on days 8-9 after plating to determine cloning efficiencies (CEs) and Hprt MFs. There was a marginal but significant reduction in the growth of splenic T cells from mice exposed to 3 ppm (n=27) compared with control mice (n=24) (P=0.004), suggesting the occurrence of BD-induced cytotoxicity at this low exposure concentration. In addition, the average Hprt MF in mice exposed to 3 ppm BD [1.54+/-0.82 (S.D.)x10(-6)] was significantly increased by 1.6-fold over the average control value of 0.96+/-0.51 (S.D.)x10(-6) (P=0.004). Comparisons of these data to earlier Hprt mutagenicity studies of mice exposed to high concentrations of BD (where significant mutagenic but not cytotoxic effects were observed) indicate that the ability to detect the cytotoxic and mutagenic responses of T cells to low levels of BD was enhanced by using a much larger sample size than usual for both the control and treatment groups. Additional analyses of the quantitative relationships between CE and MF demonstrated that CE had no significant effect upon MF values in sham-exposed control mice or mice exposed to low-level BD. Furthermore, the approaches for assessing the impact of CE and clonality on Hprt MFs in these control and BD-exposed mice were applied with the same rigor as in in vivo Hprt mutagenicity studies in human children. The overall study results support the conclusion that short-term low-level BD exposure is mutagenic in the mouse.
Collapse
Affiliation(s)
- Q Meng
- Wadsworth Center for Laboratories and Research, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, NY 12201-0509, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Bourgeois JA, Chozinski JP, Walker DM, Orr K, Wisniewski W. Psychiatric treatment and operational readiness: clinical guidelines for Air Force practice. Mil Med 2001; 166:378-81. [PMID: 11370197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
Clinical criteria for psychiatric illnesses that are career limiting to active duty Air Force personnel are defined in Air Force Instruction (AFI) 48-123. The terms used in the AFI are not sufficiently specific to the standards of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The authors review AFI 48-123 for conditions commonly seen in Air Force mental health practice and offer clinical interpretation of this AFI to bring it into line with DSM-IV. As a result of this synthesis, decisions regarding which mental health conditions warrant medical evaluation board disposition are clearer and more uniform. Clinicians and administrators are encouraged to refer to this paper for assistance in making decisions on mental health patients.
Collapse
Affiliation(s)
- J A Bourgeois
- Department of Psychiatry, University of California, Davis, Sacramento, CA 95817, USA
| | | | | | | | | |
Collapse
|
35
|
Walker DM, Wray R. Temporary cardiac pacing and the physicians of tomorrow. Clin Med (Lond) 2001; 1:247-8. [PMID: 11446628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
|
36
|
Bourgeois JA, Chozinski JP, Walker DM. Psychiatric residents as CME presenters. Psychiatr Serv 2001; 52:389. [PMID: 11239118 DOI: 10.1176/appi.ps.52.3.389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
37
|
Low EO, Gibbins JR, Walker DM. In situ detection of specific p53 mutations in cultured cells using the amplification refractory mutation system polymerase chain reaction. Diagn Mol Pathol 2000; 9:210-20. [PMID: 11129445 DOI: 10.1097/00019606-200012000-00006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Accurate molecular detection of genetic mutations involved in tumorigenesis has been based predominantly on analysis of extracted DNA, but this does not provide detailed information on the location, number, type or clonal distribution of mutated cells and their precise anatomic location and clonal distribution. This study has used a sensitive and specific application of the amplification refractory mutation system (ARMS)-polymerase chain reaction (PCR) in situ, combined with in situ hybridization to localize and identify cells with defined p53 mutations. The ARMS-PCR was performed in situ in SW480 cells in suspension and in cells either cultured or cytospun onto glass slides. Amplified mutant DNA PCR products were detected in SW480 cells using digoxigenin-labeled probes, visually identifying cells harboring specific mutations in the p53 gene. In situ hybridization alone of the mutant cells without the amplification step was negative. Normal human fibroblasts or endothelial cells were refractory to in situ amplification. This reaction was mutation-specific as CEM cells with different p53 mutations reacted negatively. Mutant messenger RNA (mRNA) in tumor cells was also selectively amplified in situ by ARMS-PCR following reverse transcription (RT). This study demonstrates the potential of in situ ARMS-PCR or RT-ARMS-PCR for mutation analysis in situ and could have useful clinical applications.
Collapse
Affiliation(s)
- E O Low
- Oral Pathology and Oral Medicine, University of Sydney, Australia
| | | | | |
Collapse
|
38
|
Meng Q, Walker DM, Olivero OA, Shi X, Antiochos BB, Poirier MC, Walker VE. Zidovudine-didanosine coexposure potentiates DNA incorporation of zidovudine and mutagenesis in human cells. Proc Natl Acad Sci U S A 2000; 97:12667-71. [PMID: 11058153 PMCID: PMC18821 DOI: 10.1073/pnas.220203197] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Drug combinations that include nucleoside reverse transcriptase inhibitors (NRTIs) are remarkably effective in preventing maternal-viral transmission of HIV during pregnancy. However, there may be potential long-term risks for children exposed in utero. Examination of the genotoxic and mutagenic effects of two NRTIs, zidovudine [AZT (3'-azido-3'-deoxythymidine)] and didanosine [ddI (2',3'-dideoxyinosine)], in cultured human lymphoblastoid cells revealed multiplicative synergistic enhancement of AZT-DNA incorporation and mutant frequency induction in response to the combined drug exposure, as compared with single-drug exposures. Dose-related increases in DNA incorporation of AZT (as measured by a competitive RIA) and mutagenicity at the HPRT and TK loci (as assessed by cell-cloning assays) were observed in cells exposed in culture to AZT, or equimolar combinations of AZT + ddI, at exposure concentrations ranging from 3 to 30 times the maximum plasma levels found in humans. Because mutagenesis is strongly associated with tumor induction in experimental models, children exposed transplacentally to combinations of NRTIs may be at risk for cancer development later in life.
Collapse
Affiliation(s)
- Q Meng
- Laboratory of Human Toxicology and Molecular Epidemiology, Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA
| | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
Using a combination of solid phase synthesis for the preparation of N-substituted-N-acylglycines 7 followed by solution-phase ring transformation of trifluoromethylacyl munchnone intermediate 8, a library of 200 trisubstituted-5-trifluoromethylketo (TFMK) imidazoles 9 was prepared. In a sublibrary, bromoacetate resin 4 was treated with 5 amines in parallel to give N-substituted glycines 5 followed by acylation with 12 acid chlorides to provide, upon cleavage from the resin, 60 individual N-substituted-N-acylglycines 7. The glycines 7 were converted to munchnones 8 by treatment with trifluoroacetic anhydride followed by reaction with benzamidine to give trisubstituted-5-TFMK-imidazoles 9. The structural content of the library was analyzed using PlateView of the LCMS results, and individual members were isolated by automated preparative LCMS.
Collapse
Affiliation(s)
- B C Hamper
- Monsanto Company, AG Sector, 800 N. Lindbergh Boulevard, St. Louis, Missouri 63167, USA.
| | | | | | | | | | | |
Collapse
|
40
|
Low EO, Jones AM, Gibbins JR, Walker DM. Analysis of the amplification refractory mutation allele-specific polymerase chain reaction system for sensitive and specific detection of p53 mutations in DNA. J Pathol 2000; 190:512-5. [PMID: 10700003 DOI: 10.1002/(sici)1096-9896(200003)190:4<512::aid-path536>3.0.co;2-f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The sensitivity of the amplification refractory mutation allele-specific polymerase chain reaction system (ARMAS-PCR) to detect known p53 mutations was determined using DNA extracted from two human tumour cell lines collected by cytobrush, as a model for its use in exfoliative cytology. Using DNA extracted from SW480 and CEM cell lines diluted with normal human fibroblasts, a nested ARMAS-PCR was more sensitive than a non-nested version and could detect one mutated cell amongst 100 000 normal cells. When compared with PCR-single stranded conformational polymorphism, nested ARMAS-PCR was 10 000 times more sensitive for detecting mutant p53 in extracted DNA. Primer design proved to be influential on the sensitivity and specificity of the assay; increased specificity was achieved by the use of deliberate mismatches upstream from the 3' end of mutation-specific primers. ARMAS-PCR was confirmed to be specific for the mutation that each primer was designed to detect. Nested ARMAS-PCR offered a rapid and sensitive method of analysis of cells with predetermined p53 mutations and has the potential to be applied to the study of the molecular progression of cancer, including diagnosis and detection of residual disease. It could also be extended to the in situ detection of aberrant cells.
Collapse
Affiliation(s)
- E O Low
- Oral Pathology and Oral Medicine, University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW, Australia.
| | | | | | | |
Collapse
|
41
|
Walker VE, Jones IM, Crippen TL, Meng Q, Walker DM, Bauer MJ, Reilly AA, Tates AD, Nakamura J, Upton PB, Skopek TR. Relationships between exposure, cell loss and proliferation, and manifestation of Hprt mutant T cells following treatment of preweanling, weanling, and adult male mice with N-ethyl-N-nitrosourea. Mutat Res 1999; 431:371-88. [PMID: 10636002 DOI: 10.1016/s0027-5107(99)00180-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Experiments were performed to characterize the age-related patterns of appearance and frequency of hypoxanthine-guanine phosphoribosyl transferase (Hprt) mutant T lymphocytes in thymus and spleen following exposure of preweanling (12-day-old), weanling (22-day-old), and young adult (8-week-old) male B6C3F1 mice to ethylnitrosourea (ENU). Mice were given single i.p. injections of 0 or 40 mg ENU/kg and then groups of animals were necropsied from 2 h to 116 days after treatment to examine the relationships between exposure, cell loss and proliferation, and the frequency of Hprt mutant T cells in thymus and spleen. Hprt mutant frequency (Mf) data for thymus of ENU-exposed (0, 11.7, 35, 58, or 72 mg/kg, or five weekly doses of 1.7 mg/kg i.p.) male C57BL/6 mice (12- or 62-week-old), obtained during an earlier study of spleen cells [I.M. Jones, K. Burkhart-Schultz, C.L. Strout, T.L. Crippen, Factors that affect the frequency of thioguanine-resistant lymphocytes in mice following exposure to ethylnitrosourea, Environ. Mutagen, 9 (1987) 317-329.], were compared to results in B6C3F1 mice. Isolated T cells were cultured in the presence of mitogen, growth factor, and 6-thioguanine to detect Hprt mutants. The time required to achieve maximum Mfs in thymus was uniformly found at 2 weeks after ENU treatment, while the times needed to reach peak values in spleen were proportional to animal age at treatment. These data indicate that age-related differences in the appearance of Hprt mutant cells in spleen are largely defined by the physiologically based, age-dependent trafficking of mutant cells from or through the thymus. Three modes of handling the resulting Hprt Mf data were evaluated: (i) comparing the Mfs at a single time point, (ii) comparing the maximum Mfs observed, and (iii) comparing the change in Mfs over time (or the mutant T cell 'manifestation' curves in treated vs. control mice) in each age group post-exposure. Measuring the Mfs in spleen at multiple time points after cessation of exposure and integrating the frequency of mutants as a function of time appeared to be the superior method for comparing mutagenic responses in different age groups. Some of the underlying assumptions of this approach, as well as its strengths and weaknesses, are discussed.
Collapse
Affiliation(s)
- V E Walker
- Department of Pathology, University of North Carolina, Chapel Hill 27599, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Loida PJ, Thompson RL, Walker DM, CaJacob CA. Novel inhibitors of glutamyl-tRNA(Glu) reductase identified through cell-based screening of the heme/chlorophyll biosynthetic pathway. Arch Biochem Biophys 1999; 372:230-7. [PMID: 10600160 DOI: 10.1006/abbi.1999.1505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The metabolite 5-aminolevulinic acid (ALA) is an early committed intermediate in the biosynthetic pathway of heme and chlorophyll formation. In plants, 5-aminolevulinic acid is synthesized via a two-step pathway in which glutamyl-tRNA(Glu) is reduced by glutamyl-tRNA(Glu) reductase (GluTR) to glutamate 1-semialdehyde, followed by transformation to 5-aminolevulinic acid catalyzed by glutamate 1-semialdehyde aminotransferase. Using an Escherichia coli cell-based high-throughput assay to screen small molecule libraries, we identified several chemical classes that specifically inhibit heme/chlorophyll biosynthesis at this point by demonstrating that the observed cell growth inhibition is reversed by supplementing the medium with 5-aminolevulinic acid. These compounds were further tested in vitro for inhibition of the purified enzymes GluTR and glutamate 1-semialdehyde aminotransferase as confirmation of the specificity and site of action. Several promising compounds were identified from the high-throughput screen that inhibit GluTR with an I(0.5) of less than 10 microM. Our results demonstrate the efficacy of cell-based high-throughput screening for identifying inhibitors of 5-aminolevulinic acid biosynthesis, thus representing the first report of exogenous inhibitors of this enzyme.
Collapse
Affiliation(s)
- P J Loida
- Monsanto Company, 700 Chesterfield Parkway, Chesterfield, Missouri, 63198, USA.
| | | | | | | |
Collapse
|
43
|
Walker DM, Tufillaro NB. Phase space reconstruction using input-output time series data. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1999; 60:4008-13. [PMID: 11970237 DOI: 10.1103/physreve.60.4008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/1999] [Indexed: 04/18/2023]
Abstract
In this paper we suggest that an extension of a procedure recently proposed by Wayland et al. [Phys. Rev. Lett. 70, 580 (1993)] for recognizing determinism in an autonomous time series can also be used as a diagnostic for determining an appropriate embedding dimension for driven ("input-output") systems. We compare the results of this extension to the results produced by the extensions to the method of false nearest neighbors put forward by Rhodes and Morari [Proceedings of the American Control Conference, Seattle, edited by The American Automatic Control Council (IEEE, Piscataway, 1995)] and the method of averaged false nearest neighbors by Cao et al. [Int. J. Bifurcation Chaos 8, 1491 (1998)].
Collapse
Affiliation(s)
- D M Walker
- Department of Applied Science, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | | |
Collapse
|
44
|
Meng Q, Henderson RF, Walker DM, Bauer MJ, Reilly AA, Walker VE. Mutagenicity of the racemic mixtures of butadiene monoepoxide and butadiene diepoxide at the Hprt locus of T-lymphocytes following inhalation exposures of female mice and rats. Mutat Res 1999; 429:127-40. [PMID: 10434028 DOI: 10.1016/s0027-5107(99)00105-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to determine if Hprt mutant frequency (Mf) data from rodents exposed directly to individual epoxy metabolites of 1,3-butadiene (BD) can be used to identify the relative significance of each intermediate in the mutagenicity of BD in mice vs. rats. To this end, the relative contributions of the racemic mixtures of BD monoepoxide (BDO) and BD diepoxide (BDO(2)) to BD-induced mutagenicity was investigated by exposing mice and rats to selected concentrations of BDO and BDO(2) (i.e., 2.5 and 4.0 ppm, respectively) and comparing the mutagenic potency of each intermediate to that of BD (at 62.5 ppm) when comparable blood levels of metabolites are achieved (in the mouse). Female B6C3F1 mice and F344 rats (4-5 weeks old) were exposed to rac-BDO (0, 2.5, or 25 ppm) or (+/-)-BDO(2) (0, 2, 4 ppm) by inhalation for 4 weeks (6 h/day, 5 days/week), and then groups of control and exposed animals (n=3-12/group) were necropsied at multiple time points post-exposure for measuring Hprt Mfs in splenic lymphocytes (via the T-cell cloning assay) and estimating mutagenic potencies (represented by the difference in the areas under the mutant T-cell 'manifestation' curves of treated vs. control animals). The resulting Mf data, along with the extant metabolism data, suggest that at lower BD exposures (</=62.5 ppm) (+/-)-BDO(2) is a major contributor to the mutagenicity of BD in mice, whereas other metabolites and stereochemical configurations are responsible for mutations in BD-exposed rats and for the incremental mutagenic effects at higher BD exposures in mice. These studies indicate that additional work is needed to determine more definitively the relative contributions of these and other metabolites and stereochemical forms to BD-induced mutagenicity. Also, the novel approach of measuring mutagenic potencies as the change in Hprt Mfs over time in T-cells of exposed vs. control animals, as used in this study, can be valuable for predicting the potential role of these intermediates in each species.
Collapse
Affiliation(s)
- Q Meng
- Wadsworth Center, New York State Department of Health, Albany, NY, 12201-0509, USA
| | | | | | | | | | | |
Collapse
|
45
|
Meng Q, Henderson RF, Chen T, Heflich RH, Walker DM, Bauer MJ, Reilly AA, Walker VE. Mutagenicity of 1,3-butadiene at the Hprt locus of T-lymphocytes following inhalation exposures of female mice and rats. Mutat Res 1999; 429:107-25. [PMID: 10434027 DOI: 10.1016/s0027-5107(99)00104-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The species specific response to 1,3-butadiene (BD), an important industrial chemical, was investigated by determining the influence of exposure duration and exposure concentration on the mutagenicity of BD in mice and rats and by defining the spectra of mutations in the Hprt gene T-cell mutants from control and BD-exposed mice. Female B6C3F1 mice and F344 rats (4-5 weeks old) were exposed by inhalation to 0, 20, 62.5, or 625 ppm of BD for up to 4 weeks (6 h/day, 5 days/week). Groups of control and exposed animals (n=4-12/group) were necropsied at multiple time points after exposure and the T-cell cloning assay was used to measure Hprt mutant frequencies in lymphocytes isolated from spleen. Mutant clones collected from control and BD-exposed mice were propagated and analyzed by RT-PCR to produce Hprt cDNA for sequencing. In animals necropsied 4 weeks after 2 or 4 weeks of BD exposure (0 or 625 ppm), the rate of accumulation of mutations was greater in mice than in rats. Supra-linear dose-response curves were observed in BD-exposed mice, indicating a higher efficiency of mutant induction at lower concentrations of BD. The mutagenic potency estimates (represented by the differences in the areas under the mutant T-cell 'manifestation' curves of treated vs. control animals) in mice were 11 and 61 following 4 weeks of exposures to 62.5 and 625 ppm of BD, respectively, while mutant frequencies (Mfs) in rats were significantly increased only at 625 ppm BD (mutagenic potency of 7). Molecular analysis of Hprt cDNA from expanded T-cell clones from control and BD-exposed mice demonstrated an increased frequency of mutants in exposed animals that likely contain large deletions in the Hprt gene (P=0.016). These data indicate that both exposure duration and exposure concentration are important in determining the magnitude of mutagenic response to BD, and that mutagenic and carcinogenic properties of BD in mice may be related more to the ability of its metabolites to cause chromosomal deletions than to produce point mutations.
Collapse
Affiliation(s)
- Q Meng
- Wadsworth Center, New York State Department of Health, Albany, NY 12201-0509, USA
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Clague MJ, Jones AT, Mills IG, Walker DM, Urbé S. Regulation of early-endosome dynamics by phosphatidylinositol 3-phosphate binding proteins. Biochem Soc Trans 1999; 27:662-6. [PMID: 10917662 DOI: 10.1042/bst0270662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M J Clague
- The Physiological Laboratory, University of Liverpool, UK
| | | | | | | | | |
Collapse
|
47
|
Patt WC, Cheng XM, Repine JT, Lee C, Reisdorph BR, Massa MA, Doherty AM, Welch KM, Bryant JW, Flynn MA, Walker DM, Schroeder RL, Haleen SJ, Keiser JA. Butenolide endothelin antagonists with improved aqueous solubility. J Med Chem 1999; 42:2162-8. [PMID: 10377221 DOI: 10.1021/jm980504w] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Continued development around our ETA-selective endothelin (ET) antagonist 1 (CI-1020) has led to the synthesis of analogues with improved aqueous solubility profiles. Poor solubility characteristics displayed by 1 required a complex buffered formulation in order to conduct iv studies. To overcome the use of specific iv formulations for preclinical studies on additional drug candidates, analogues with improved aqueous solubility were desired. Several analogues were synthesized with substitution patterns that allowed for the formation of either acid or base addition salts. These derivatives had dramatically improved aqueous solubility. In addition, these analogues retained equivalent or improved ETA receptor selectivity and antagonist potency, versus 1, both in vitro and in vivo. Compound 29, which contains as a substituent the sodium salt of a sulfonic acid, has an ETA IC50 = 0.38 nM, ETA selectivity of 4200-fold, and ETA functional activity of KB = 7.8, all of which are similar or superior to those of 1. Compound 29 also has vastly superior aqueous solubility and solubility duration, compared to 1. Furthermore, 29 after iv infusion displays improved activity to 1 in preventing acute hypoxia-induced pulmonary hypertension in rats with an ED50 = 0.3 microg/kg/h.
Collapse
Affiliation(s)
- W C Patt
- Department of Chemistry, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Bouloux GF, Walker DM, McKellar G. Massive osteolysis of the mandible: report of a case with multifocal bone loss. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1999; 87:357-61. [PMID: 10102600 DOI: 10.1016/s1079-2104(99)70223-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Osteolysis of the jaws has been reported in association with infection, cysts, neoplasia, and metabolic, endocrine, or hematologic abnormalities. Rare cases of idiopathic osteolysis have also been recorded. We report the case of a 10-year-old girl with mandibular basal and alveolar bone resorption that has continued over a period of 9 years. The patient has subsequently developed bilateral resorption of the ascending rami and condyles. The maxilla is uninvolved. Investigations included radiology, computerized tomography, scintigraphy, hematology, serum chemistry, endocrinology, histopathology, microbiology, and immunology. Neutrophil chemotaxis, chemiluminescence, and random migration values were low but within the normal range. These findings are interpreted as indicating an unusual variant of massive osteolysis.
Collapse
Affiliation(s)
- G F Bouloux
- Department of Oral and Maxillofacial Surgery, Westmead Hospital, Sydney, Australia
| | | | | |
Collapse
|
49
|
Walker VE, Andrews JL, Upton PB, Skopek TR, deBoer JG, Walker DM, Shi X, Sussman HE, Gorelick NJ. Detection of cyclophosphamide-induced mutations at the Hprt but not the lacI locus in splenic lymphocytes of exposed mice. Environ Mol Mutagen 1999; 34:167-181. [PMID: 10529741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The relative sensitivities and specificities of the endogenous Hprt gene and the lacI transgene as mutational targets were evaluated in splenic lymphocytes from male standard B6C3F1 mice (only Hprt assayed) and from lacI transgenic B6C3F1 mice treated at 6-7 weeks- of-age with the indirect-acting agent, cyclophosphamide (CP). To define the effects of the time elapsed since CP treatment on Hprt mutant frequencies (Mfs), nontransgenic mice were given single i.p. injections of 25 mg CP/kg or vehicle (PBS) alone and then necropsied 2, 4, 6, 8, or 10 weeks after treatment. Peak Mfs were found at 6 weeks postexposure, with mean Mf values ranging from 2.27 to 3.27 x 10(-5) using two different lots of CP in standard packaging (compared with mean control Mf values of 0.14 to 0.26 x 10(-5) in various experiments). To determine the dose response for Hprt Mfs, nontransgenic mice were given single doses of 0, 12.5, 25, 50, or 100 mg CP/kg and necropsied 4 weeks postexposure. These treatments produced a supralinear dose response curve for CP-induced Hprt Mfs. Based on these experiments, CP mutagenicities at Hprt and lacI were compared in transgenic mice treated with 0, 25, or 100 mg CP/kg (using another lot of CP in ISOPAC((R)) bottles; Sigma) and necropsied 6 weeks later. There was a significant increase in Hprt Mfs in treated transgenic mice (100 mg CP/kg: 0.75 +/- 0.09 x 10(-5); 25 mg CP/kg: 0.39 +/- 0.05 x 10(-5)) versus controls (0.10 +/- 0.01 x 10(-5)); however, the Mfs in lacI of lymphocytes from the same CP-treated animals were not significantly different from controls (100 mg CP/kg: 9.4 +/- 1.1 x 10(-5); 25 mg CP/kg: 6.7 +/- 0. 8 x 10(-5); control: 7.7 +/- 0.7 x 10(-5)). Hprt mutational spectra data in CP-treated transgenic and nontransgenic mice were different from those of control mice, whereas the spectra of mutations in lacI of lymphocytes from Big Blue((R)) transgenic mice were not significantly changed after CP treatment. These data indicate that, under these treatment conditions, CP-induced mutations in splenic lymphocytes were detectable in the Hprt gene but not the lacI transgene of this nontarget tissue for CP-induced cancer.
Collapse
Affiliation(s)
- V E Walker
- Department of Pathology and Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, USA. walker@ wadsworth.org
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
|