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Hussain I, Powell D, Howlett DR, Tew DG, Meek TD, Chapman C, Gloger IS, Murphy KE, Southan CD, Ryan DM, Smith TS, Simmons DL, Walsh FS, Dingwall C, Christie G. Identification of a novel aspartic protease (Asp 2) as beta-secretase. Mol Cell Neurosci 1999; 14:419-27. [PMID: 10656250 DOI: 10.1006/mcne.1999.0811] [Citation(s) in RCA: 828] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Alzheimer's disease beta-amyloid peptide (Abeta) is produced by excision from the type 1 integral membrane glycoprotein amyloid precursor protein (APP) by the sequential actions of beta- and then gamma-secretases. Here we report that Asp 2, a novel transmembrane aspartic protease, has the key activities expected of beta-secretase. Transient expression of Asp 2 in cells expressing APP causes an increase in the secretion of the N-terminal fragment of APP and an increase in the cell-associated C-terminal beta-secretase APP fragment. Mutation of either of the putative catalytic aspartyl residues in Asp 2 abrogates the production of the fragments characteristic of cleavage at the beta-secretase site. The enzyme is present in normal and Alzheimer's disease (AD) brain and is also found in cell lines known to produce Abeta. Asp 2 localizes to the Golgi/endoplasmic reticulum in transfected cells and shows clear colocalization with APP in cells stably expressing the 751-amino-acid isoform of APP.
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828 |
2
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Chapman AL, Hadfield M, Chapman CJ. Qualitative research in healthcare: an introduction to grounded theory using thematic analysis. J R Coll Physicians Edinb 2016; 45:201-5. [PMID: 26517098 DOI: 10.4997/jrcpe.2015.305] [Citation(s) in RCA: 353] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In today's NHS, qualitative research is increasingly important as a method of assessing and improving quality of care. Grounded theory has developed as an analytical approach to qualitative data over the last 40 years. It is primarily an inductive process whereby theoretical insights are generated from data, in contrast to deductive research where theoretical hypotheses are tested via data collection. Grounded theory has been one of the main contributors to the acceptance of qualitative methods in a wide range of applied social sciences. The influence of grounded theory as an approach is, in part, based on its provision of an explicit framework for analysis and theory generation. Furthermore the stress upon grounding research in the reality of participants has also given it credence in healthcare research. As with all analytical approaches, grounded theory has drawbacks and limitations. It is important to have an understanding of these in order to assess the applicability of this approach to healthcare research. In this review we outline the principles of grounded theory, and focus on thematic analysis as the analytical approach used most frequently in grounded theory studies, with the aim of providing clinicians with the skills to critically review studies using this methodology.
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Review |
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353 |
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McCloskey EV, MacLennan IC, Drayson MT, Chapman C, Dunn J, Kanis JA. A randomized trial of the effect of clodronate on skeletal morbidity in multiple myeloma. MRC Working Party on Leukaemia in Adults. Br J Haematol 1998; 100:317-25. [PMID: 9488619 DOI: 10.1046/j.1365-2141.1998.00567.x] [Citation(s) in RCA: 246] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In patients with multiple myeloma, despite a major reduction of bone pain achieved with chemotherapy, skeletal disease continues to progress. The effects of clodronate, an inhibitor of osteoclastic bone resorption, are evaluated on the natural history of skeletal disease in patients with newly diagnosed multiple myeloma. Within the framework of the VIth MRC Multiple Myeloma Trial, 536 patients (218 women, 318 men) with recently diagnosed multiple myeloma were randomized to receive either clodronate 1600 mg daily (n=264) or an outwardly identical placebo (n=272) in addition to chemotherapy. Treatment with clodronate was associated with a 50% decrease in the proportion of patients with severe hypercalcaemia (5.1% v 10.1%, P=0.06) and a similar reduction in reported non-vertebral fractures (6.8% v 13.2%, P=0.04). Fewer patients receiving clodronate sustained vertebral fractures after entry to the trial (38% v 55%, P=0.01) and patients also lost less height over 3 years compared to those receiving placebo (2.0 v 3.4 cm, P=0.01). Biochemical indices of bone turnover were significantly lower in patients receiving concomitant clodronate, both at plateau and at disease relapse. The frequencies of back pain and poor performance status were significantly lower at 24 months in clodronate than in placebo-treated patients (10.9% v 19.9%, P=0.05, and 18.3% v 30.5% P=0.03 respectively.) There was no statistically significant difference in survival between the clodronate and placebo treated patients. The study indicates that long-term oral clodronate slows the progression of skeletal disease in multiple myeloma and decreases the associated morbidity. Patients without overt skeletal disease at diagnosis were also found to benefit from clodronate, indicating that this treatment should be initiated as early in the course of the disease as possible.
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Clinical Trial |
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Chapman C, Murray A, Chakrabarti J, Thorpe A, Woolston C, Sahin U, Barnes A, Robertson J. Autoantibodies in breast cancer: their use as an aid to early diagnosis. Ann Oncol 2007; 18:868-73. [PMID: 17347129 DOI: 10.1093/annonc/mdm007] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND There is increasing evidence that the immune system produces a humoral response to cancer-derived antigens. This study assessed the diagnostic potential of autoantibodies to multiple known tumour-associated proteins. PATIENTS AND METHODS Sera from normal controls (n = 94), primary breast cancer patients (n = 97) and patients with ductal carcinoma in situ (DCIS) (n = 40) were investigated for the presence of autoantibodies to p53, c-myc, HER2, NY-ESO-1, BRCA1, BRCA2 and MUC1 antigens by enzyme-linked immunosorbent assay. RESULTS Reproducibly elevated levels of autoantibodies were seen in at least one of the six antigens in 64% of primary breast cancer patient sera and 45% of patients with DCIS at a specificity of 85%. No significant differences were seen when patients were subdivided by age, tumour size, histological grade, lymph node status or detection methodology. CONCLUSIONS Autoantibodies against one or more of these tumour-associated antigens appears to indicate the presence of early-stage breast cancers. Autoantibody assays against a panel of antigens could be used as an aid to mammography in the detection and diagnosis of early primary breast cancer, especially in younger women at increased risk of breast cancer where mammography is known to have reduced sensitivity and specificity.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antibodies, Neoplasm/blood
- Antigens, Neoplasm/blood
- Autoantibodies/blood
- Breast Neoplasms/blood
- Breast Neoplasms/immunology
- Breast Neoplasms/pathology
- Carcinoma, Intraductal, Noninfiltrating/blood
- Carcinoma, Intraductal, Noninfiltrating/immunology
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Carcinoma, Lobular/blood
- Carcinoma, Lobular/immunology
- Carcinoma, Lobular/pathology
- Case-Control Studies
- Cohort Studies
- Early Diagnosis
- Enzyme-Linked Immunosorbent Assay
- Female
- Humans
- Middle Aged
- Neoplasm Metastasis/pathology
- Receptors, Estrogen/blood
- Receptors, Estrogen/immunology
- Reproducibility of Results
- Sensitivity and Specificity
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Research Support, Non-U.S. Gov't |
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213 |
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Swaney JS, Chapman C, Correa LD, Stebbins KJ, Bundey RA, Prodanovich PC, Fagan P, Baccei CS, Santini AM, Hutchinson JH, Seiders TJ, Parr TA, Prasit P, Evans JF, Lorrain DS. A novel, orally active LPA(1) receptor antagonist inhibits lung fibrosis in the mouse bleomycin model. Br J Pharmacol 2010; 160:1699-713. [PMID: 20649573 PMCID: PMC2936842 DOI: 10.1111/j.1476-5381.2010.00828.x] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 03/10/2010] [Accepted: 03/16/2010] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE The aim of this study was to assess the potential of an antagonist selective for the lysophosphatidic acid receptor, LPA(1), in treating lung fibrosis We evaluated the in vitro and in vivo pharmacological properties of the high affinity, selective, oral LPA(1)-antagonist (4'-{4-[(R)-1-(2-chloro-phenyl)-ethoxycarbonylamino]-3-methyl-isoxazol-5-yl}-biphenyl-4-yl)-acetic acid (AM966). EXPERIMENTAL APPROACH The potency and selectivity of AM966 for LPA(1) receptors was determined in vitro by calcium flux and cell chemotaxis assays using recombinant and native cell cultures. The in vivo efficacy of AM966 to reduce tissue injury, vascular leakage, inflammation and fibrosis was assessed at several time points in the mouse bleomycin model. KEY RESULTS AM966 was a potent antagonist of LPA(1) receptors, with selectivity for this receptor over the other LPA receptors. In vitro, AM966 inhibited LPA-stimulated intracellular calcium release (IC(50)= 17 nM) from Chinese hamster ovary cells stably expressing human LPA(1) receptors and inhibited LPA-induced chemotaxis (IC(50)= 181 nM) of human IMR-90 lung fibroblasts expressing LPA(1) receptors. AM966 demonstrated a good pharmacokinetic profile following oral dosing in mice. In the mouse, AM966 reduced lung injury, vascular leakage, inflammation and fibrosis at multiple time points following intratracheal bleomycin instillation. AM966 also decreased lactate dehydrogenase activity and tissue inhibitor of metalloproteinase-1, transforming growth factor beta1, hyaluronan and matrix metalloproteinase-7, in bronchoalveolar lavage fluid. CONCLUSIONS AND IMPLICATIONS These findings demonstrate that AM966 is a potent, selective, orally bioavailable LPA(1) receptor antagonist that may be beneficial in treating lung injury and fibrosis, as well as other diseases that are characterized by pathological inflammation, oedema and fibrosis.
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research-article |
15 |
202 |
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Veverka J, Robinson M, Thomas P, Murchie S, Bell JF, Izenberg N, Chapman C, Harch A, Bell M, Carcich B, Cheng A, Clark B, Domingue D, Dunham D, Farquhar R, Gaffey MJ, Hawkins E, Joseph J, Kirk R, Li H, Lucey P, Malin M, Martin P, McFadden L, Merline WJ, Miller JK. NEAR at eros: imaging and spectral results. Science 2000; 289:2088-97. [PMID: 11000105 DOI: 10.1126/science.289.5487.2088] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Eros is a very elongated (34 kilometers by 11 kilometers by 11 kilometers) asteroid, most of the surface of which is saturated with craters smaller than 1 kilometer in diameter. The largest crater is 5.5 kilometers across, but there is a 10-kilometer saddle-like depression with attributes of a large degraded crater. Surface lineations, both grooves and ridges, are prominent on Eros; some probably exploit planes of weakness produced by collisions on Eros and/or its parent body. Ejecta blocks (30 to 100 meters across) are abundant but not uniformly distributed over the surface. Albedo variations are restricted to the inner walls of certain craters and may be related to downslope movement of regolith. On scales of 200 meters to 1 kilometer, Eros is more bland in terms of color variations than Gaspra or Ida. Spectra (800 to 2500 nanometers) are consistent with an ordinary chondrite composition for which the measured mean density of 2.67 +/- 0.1 grams per cubic centimeter implies internal porosities ranging from about 10 to 30 percent.
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200 |
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Veverka J, Farquhar B, Robinson M, Thomas P, Murchie S, Harch A, Antreasian PG, Chesley SR, Miller JK, Owen WM, Williams BG, Yeomans D, Dunham D, Heyler G, Holdridge M, Nelson RL, Whittenburg KE, Ray JC, Carcich B, Cheng A, Chapman C, Bell JF, Bell M, Bussey B, Clark B, Domingue D, Gaffey MJ, Hawkins E, Izenberg N, Joseph J, Kirk R, Lucey P, Malin M, McFadden L, Merline WJ, Peterson C, Prockter L, Warren J, Wellnitz D. The landing of the NEAR-Shoemaker spacecraft on asteroid 433 Eros. Nature 2001; 413:390-3. [PMID: 11574879 DOI: 10.1038/35096507] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The NEAR-Shoemaker spacecraft was designed to provide a comprehensive characterization of the S-type asteroid 433 Eros (refs 1,2,3), an irregularly shaped body with approximate dimensions of 34 x 13 x 13 km. Following the completion of its year-long investigation, the mission was terminated with a controlled descent to its surface, in order to provide extremely high resolution images. Here we report the results of the descent on 12 February 2001, during which 70 images were obtained. The landing area is marked by a paucity of small craters and an abundance of 'ejecta blocks'. The properties and distribution of ejecta blocks are discussed in a companion paper. The last sequence of images reveals a transition from the blocky surface to a smooth area, which we interpret as a 'pond'. Properties of the 'ponds' are discussed in a second companion paper. The closest image, from an altitude of 129 m, shows the interior of a 100-m-diameter crater at 1-cm resolution.
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Chapman CJ, Murray A, McElveen JE, Sahin U, Luxemburger U, Türeci O, Wiewrodt R, Barnes AC, Robertson JF. Autoantibodies in lung cancer: possibilities for early detection and subsequent cure. Thorax 2007; 63:228-33. [PMID: 17932110 DOI: 10.1136/thx.2007.083592] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND People with lung cancer usually present at a late stage in the course of their disease when their chances of long-term survival are low. At present there is little to offer for early diagnosis, even in those at high risk of developing the disease. Autoantibodies have been shown to be present in the circulation of people with various forms of solid tumour before cancer-associated antigens can be detected, and these molecules can be measured up to 5 years before symptomatic disease. OBJECTIVE To assess the potential of a panel of tumour-associated autoantibody profiles as an aid to other lung cancer screening modalities. METHODS Plasma from normal controls (n = 50), patients with non-small cell lung cancer (n = 82) and patients with small cell lung cancer (n = 22) were investigated for the presence of autoantibodies to p53, c-myc, HER2, NY-ESO-1, CAGE, MUC1 and GBU4-5 by enzyme-linked immunosorbent assay. RESULTS Raised levels of autoantibodies were seen to at least 1/7 antigens in 76% of all the patients with lung cancer plasma tested, and 89% of node-negative patients, with a specificity of 92%. There was no significant difference between the detection rates in the lung cancer subgroups, although more patients with squamous cell carcinomas (92%) could be identified. CONCLUSION Measurement of an autoantibody response to one or more tumour-associated antigens in an optimised panel assay may provide a sensitive and specific blood test to aid the early detection of lung cancer.
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Research Support, Non-U.S. Gov't |
18 |
164 |
9
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Quigley JD, Lago A, Chapman C, Erickson P, Polo J. Evaluation of the Brix refractometer to estimate immunoglobulin G concentration in bovine colostrum. J Dairy Sci 2012. [PMID: 23200468 DOI: 10.3168/jds.2012-5823] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Refractometry using a Brix refractometer has been proposed as a means to estimate IgG concentration in bovine maternal colostrum (MC). The refractometer has advantages over other methods of estimating IgG concentration in that the Brix refractometer is inexpensive, readily available, less fragile, and less sensitive to variation in colostral temperature, season of the year and other factors. Samples of first-milking MC were collected from 7 dairy farms in Maine, New Hampshire, Vermont, and Connecticut (n=84) and 1 dairy farm in California (n=99). The MC was milked from the cow at 6.1 ± 5.6h postparturition and a sample was evaluated for Brix percentage by using an optical refractometer. Two additional samples (30 mL) were collected from the milk bucket, placed in vials, and frozen before analysis of total IgG by radial immunodiffusion (RID) using commercially available plates and by turbidimetric immunoassay (TIA). The second sample was analyzed for total bacterial counts and coliform counts at laboratories in New York (Northeast samples) and California (California samples). The Brix percentage (mean ± SD) was 23.8 ± 3.5, IgG concentration measured by RID was 73.4 ± 26.2g/L, and IgG concentration measured by TIA was 67.5 ± 25.0 g/L. The Brix percentage was highly correlated (r=0.75) with IgG analyzed by RID. The Brix percentage cut point to define high- or low-quality colostrum (50 g of IgG/L measured by RID) that classified more samples correctly given the proportion of high- (86%) and low-quality (14%) samples in this study was 21%, which is slightly lower than other recent estimates of Brix measurements. At this cut point, the test sensitivity, specificity, positive and negative predictive values, and accuracy were 92.9, 65.5, 93.5, 63.3, and 88.5%, respectively. Measurement of IgG by TIA correlated with Brix (r=0.63) and RID (r=0.87); however, TIA and RID methods of IgG measurement were not consistent throughout the range of samples tested. We conclude that Brix measurement of total solids in fresh MC is an inexpensive, rapid, and satisfactorily accurate method of estimating IgG concentration. A cut point of 21% Brix to estimate samples of MC >50 g/L was most appropriate for our data. Measurement of IgG in MC by TIA differed from measurement by RID.
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Research Support, Non-U.S. Gov't |
13 |
156 |
10
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Belton MJ, Veverka J, Thomas P, Helfenstein P, Simonelli D, Chapman C, Davies ME, Greeley R, Greenberg R, Head J, Murchie S, Klaasen K, Johnson TV, McEwen A, Morrison D, Neukum G, Fanale F, Anger C, Carr M, Pilcher C. Galileo Encounter with 951 Gaspra: First Pictures of an Asteroid. Science 1992; 257:1647-52. [PMID: 17841160 DOI: 10.1126/science.257.5077.1647] [Citation(s) in RCA: 154] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Galileo images of Gaspra reveal it to be an irregularly shaped object (19 by 12 by 11 kilometers) that appears to have been created by a catastrophic collisional disruption of a precursor parent body. The cratering age of the surface is about 200 million years. Subtle albedo and color variations appear to correlate with morphological features: Brighter materials are associated with craters especially along the crests of ridges, have a stronger 1-micrometer absorption, and may represent freshly excavated mafic materials; darker materials exhibiting a significantly weaker 1-micrometer absorption appear concentrated in interridge areas. One explanation of these patterns is that Gaspra is covered with a thin regolith and that some of this material has migrated downslope in some areas.
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33 |
154 |
11
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Boyle P, Chapman CJ, Holdenrieder S, Murray A, Robertson C, Wood WC, Maddison P, Healey G, Fairley GH, Barnes AC, Robertson JFR. Clinical validation of an autoantibody test for lung cancer. Ann Oncol 2010; 22:383-9. [PMID: 20675559 PMCID: PMC3030465 DOI: 10.1093/annonc/mdq361] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC). Patients and methods: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage. Results: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well. Conclusion: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC.
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Validation Study |
15 |
150 |
12
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Veverka J, Thomas P, Harch A, Clark B, Bell JF, Carcich B, Joseph J, Chapman C, Merline W, Robinson M, Malin M, McFadden LA, Murchie S, Hawkins SE, Farquhar R, Izenberg N, Cheng A. NEAR's flyby of 253 mathilde: images of a C asteroid. Science 1997; 278:2109-14. [PMID: 9405344 DOI: 10.1126/science.278.5346.2109] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
On 27 June 1997, the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 1212 kilometers of asteroid 253 Mathilde. Mathilde is an irregular, heavily cratered body measuring 66 kilometers by 48 kilometers by 46 kilometers. The asteroid's surface is dark (estimated albedo between 0.035 and 0.050) and similar in color to some CM carbonaceous chondrites. No albedo or color variations were detected. The volume derived from the images and the mass from Doppler tracking of the spacecraft yield a mean density of 1.3 +/- 0.2 grams per cubic centimeter, about half that of CM chondrites, indicating a porous interior structure.
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28 |
149 |
13
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Tzipori S, Wachsmuth IK, Chapman C, Birden R, Brittingham J, Jackson C, Hogg J. The pathogenesis of hemorrhagic colitis caused by Escherichia coli O157:H7 in gnotobiotic piglets. J Infect Dis 1986; 154:712-6. [PMID: 3528323 DOI: 10.1093/infdis/154.4.712] [Citation(s) in RCA: 147] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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39 |
147 |
14
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Kendrick KM, Keverne EB, Chapman C, Baldwin BA. Intracranial dialysis measurement of oxytocin, monoamine and uric acid release from the olfactory bulb and substantia nigra of sheep during parturition, suckling, separation from lambs and eating. Brain Res 1988; 439:1-10. [PMID: 3359176 DOI: 10.1016/0006-8993(88)91455-2] [Citation(s) in RCA: 130] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intracranial dialysis was used to measure the release of oxytocin (OXY), monoamines and their metabolites and uric acid (UA) from the substantia nigra (SN) and olfactory bulb (OB) of sheep during parturition, suckling, separation from lambs and eating. Results showed that OXY concentrations increased significantly during parturition, suckling and eating in the SN and during parturition and suckling in the OB. Concentrations of dopamine (DA) increased significantly in the SN during suckling and eating and in the OB during parturition and suckling. The dopamine metabolite, homovanillic acid, also increased significantly in the SN during parturition. Concentrations of the noradrenaline metabolite, 4-hydroxy-3-methoxyphenylethan-1,2-diol (MHPG) and the purine metabolite, UA, were significantly raised during parturition, suckling and separation from the lambs in the SN and increased UA levels were also found during eating. In a separate experiment it was confirmed that OXY was detectable in homogenates of both the SN and the OB. These results show that, in the sheep, OXY and DA release in the SN is associated with maternal and ingestive behaviour whereas similar release in the OB may only be related to maternal behaviour. Release of MHPG in the SN may be associated with maternal behaviour and/or stress.
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37 |
130 |
15
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Kendrick KM, Keverne EB, Chapman C, Baldwin BA. Microdialysis measurement of oxytocin, aspartate, gamma-aminobutyric acid and glutamate release from the olfactory bulb of the sheep during vaginocervical stimulation. Brain Res 1988; 442:171-4. [PMID: 2896051 DOI: 10.1016/0006-8993(88)91447-3] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Concentrations of oxytocin and amino acids were measured in microdialysis samples taken from the olfactory bulbs of 5 conscious, oestrogen-treated ewes before, during and after a 10-min period of vaginocervical stimulation. Results showed that vaginocervical stimulation induced significant increases in concentrations of oxytocin, aspartate, gamma-aminobutyric acid (GABA) and glutamate in dialysis samples. Concentrations of other amino acids measured were not affected. These findings show that vaginocervical stimulation produces significant changes in neurochemical release in the olfactory bulbs of sheep. Such changes may be involved in the induction of maternal behaviour of the olfactory recognition of offspring.
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Hussain I, Powell DJ, Howlett DR, Chapman GA, Gilmour L, Murdock PR, Tew DG, Meek TD, Chapman C, Schneider K, Ratcliffe SJ, Tattersall D, Testa TT, Southan C, Ryan DM, Simmons DL, Walsh FS, Dingwall C, Christie G. ASP1 (BACE2) cleaves the amyloid precursor protein at the beta-secretase site. Mol Cell Neurosci 2000; 16:609-19. [PMID: 11083922 DOI: 10.1006/mcne.2000.0884] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sequential proteolytic processing of the Amyloid Precursor Protein (APP) by beta- and gamma-secretases generates the 4-kDa amyloid (A beta) peptide, a key component of the amyloid plaques seen in Alzheimer's disease (AD). We and others have recently reported the identification and characterisation of an aspartic proteinase, Asp2 (BACE), as beta-secretase. Here we describe the characterization of a second highly related aspartic proteinase, Asp1 as a second beta-secretase candidate. Asp1 is expressed in brain as detected at the mRNA level and at the protein level. Transient expression of Asp1 in APP-expressing cells results in an increase in the level of beta-secretase-derived soluble APP and the corresponding carboxy-terminal fragment. Paradoxically there is a decrease in the level of soluble A beta secreted from the cells. Asp1 colocalizes with APP in the Golgi/endoplasmic reticulum compartments of cultured cells. Asp1, when expressed as an Fc fusion protein (Asp1-Fc), has the N-terminal sequence ALEP..., indicating that it has lost the prodomain. Asp1-Fc exhibits beta-secretase activity by cleaving both wild-type and Swedish variant (KM/NL) APP peptides at the beta-secretase site.
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125 |
17
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Chapman CJ, Sand O. Field studies of hearing in two species of flatfish Pleuronectes platessa (L.) and limanda limanda (L.) (family pleuronectidae). COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1974; 47:371-85. [PMID: 4149016 DOI: 10.1016/0300-9629(74)90082-6] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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51 |
122 |
18
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Veverka J, Thomas PC, Robinson M, Murchie S, Chapman C, Bell M, Harch A, Merline WJ, Bell JF, Bussey B, Carcich B, Cheng A, Clark B, Domingue D, Dunham D, Farquhar R, Gaffey MJ, Hawkins E, Izenberg N, Joseph J, Kirk R, Li H, Lucey P, Malin M, McFadden L, Miller JK, Owen WM, Peterson C, Prockter L, Warren J, Wellnitz D, Williams BG, Yeomans DK. Imaging of small-scale features on 433 Eros from NEAR: evidence for a complex regolith. Science 2001; 292:484-8. [PMID: 11313490 DOI: 10.1126/science.1058651] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
On 25 October 2000, the Near Earth Asteroid Rendevous (NEAR)-Shoemaker spacecraft executed a low-altitude flyover of asteroid 433 Eros, making it possible to image the surface at a resolution of about 1 meter per pixel. The images reveal an evolved surface distinguished by an abundance of ejecta blocks, a dearth of small craters, and smooth material infilling some topographic lows. The subdued appearance of craters of different diameters and the variety of blocks and different degrees of their burial suggest that ejecta from several impact events blanketed the region imaged at closest approach and led to the building up of a substantial and complex regolith consisting of fine materials and abundant meter-sized blocks.
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24 |
121 |
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Tzipori S, Roberton D, Chapman C. Remission of diarrhoea due to cryptosporidiosis in an immunodeficient child treated with hyperimmune bovine colostrum. BMJ 1986; 293:1276-7. [PMID: 3096462 PMCID: PMC1342109 DOI: 10.1136/bmj.293.6557.1276] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A boy aged 6 months who presented with poor weight gain, diarrhoea, and infection with Pneumocystis carinii was found to have congenital hypogammaglobulinaemia, which did not improve despite monthly treatment with intravenous gammaglobulin. At the age of 3 years and 2 months he developed severe vomiting and diarrhoea due to cryptosporidiosis, which failed to respond to conventional treatment. Infusion of hyperimmune bovine colostrum produced against parasite antigen, given by nasogastric tube, was started after symptoms had persisted for three weeks. His vomiting and diarrhoea resolved within five days of treatment, and oocysts were no longer seen in the stools after eight days. Later, however, he developed a rare complication, and oocysts were found in the common bile duct. Hyperimmune bovine colostrum may be useful in the treatment of many patients with immunodeficiency disorders.
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research-article |
39 |
119 |
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Verstraeten TC, Chapman C, Hartzer M, Winkler BS, Trese MT, Williams GA. Pharmacologic induction of posterior vitreous detachment in the rabbit. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 1993; 111:849-54. [PMID: 8512489 DOI: 10.1001/archopht.1993.01090060139038] [Citation(s) in RCA: 116] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To assay the proteolytic activity of plasmin on the vitreoretinal junction and to assess a potential facilitating effect on posterior vitreous detachment. METHODS We injected 1 U of plasmin into the vitreous of rabbits. Some eyes underwent vitrectomy after plasmin injection. Electroretinography and electron microscopy were performed. RESULTS In plasmin-treated eyes, electroretinography displayed a transient (3 days) decreased b-wave amplitude. Histologic examination demonstrated posterior vitreous detachment in eyes that received intravitreal plasmin followed by vitrectomy. CONCLUSION Plasmin may prove to be a useful biochemical adjunct to mechanical vitrectomy.
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32 |
116 |
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Glander KE, Fedigan LM, Fedigan L, Chapman C. Field methods for capture and measurement of three monkey species in Costa Rica. Folia Primatol (Basel) 1991; 57:70-82. [PMID: 1786909 DOI: 10.1159/000156567] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A total of 54 free-ranging monkeys were captured and marked in Santa Rosa National Park, Costa Rica, during May 1985, and an additional 17 were captured during March 1986. The animals were darted using a blowpipe or a CO2 gun. The drugs used were Ketaset, Sernylan and Telazol. Ketaset was effective for Cebus capucinus but unsuccessful for Alouatta palliata and Ateles geoffroyi. Sernylan was successful for A. geoffroyi and A. palliata but is no longer commercially available. Telazol proved to be an excellent alternative capture drug for both A. palliata and A. geoffroyi.
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34 |
114 |
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Till K, Cobley S, Wattie N, O'Hara J, Cooke C, Chapman C. The prevalence, influential factors and mechanisms of relative age effects in UK Rugby League. Scand J Med Sci Sports 2009; 20:320-9. [PMID: 19486487 DOI: 10.1111/j.1600-0838.2009.00884.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Relative age effects (RAEs), reflecting observed inequalities in participation and attainment as a result of annual age-grouping policies in youth sport, are common in most team sports. The aims of this study were to determine if and when RAEs become apparent in Rugby League, determine how influential variables (e.g., gender) lead and clarify whether player retention at junior representative levels can explain persistent RAEs. Player data were collected for the male and female community games ranging from Under 7s to Senior (N=15,060) levels, junior representative selections (i.e., Regional) and professional players (N=298). Chi-square analyses found significant (P<0.05) uneven birth date distributions beginning at the earliest stages of the game and throughout into senior professionals. In junior representative selections, 47.0% of Regional and 55.7% of National representative players were born in Quartile 1, with RAE risk increasing with performance level. Gender and nationality were also found to moderate RAE risk. When tracking representative juniors, over 50% were retained for similar competition the following season. Findings clearly demonstrate that RAEs exist throughout Rugby League with early selection, performance level and retention processes, appearing to be key contributing factors responsible for RAE persistence.
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Journal Article |
16 |
107 |
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Swaney JS, Chapman C, Correa LD, Stebbins KJ, Broadhead AR, Bain G, Santini AM, Darlington J, King CD, Baccei CS, Lee C, Parr TA, Roppe JR, Seiders TJ, Ziff J, Prasit P, Hutchinson JH, Evans JF, Lorrain DS. Pharmacokinetic and pharmacodynamic characterization of an oral lysophosphatidic acid type 1 receptor-selective antagonist. J Pharmacol Exp Ther 2011; 336:693-700. [PMID: 21159750 DOI: 10.1124/jpet.110.175901] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2025] Open
Abstract
Lysophosphatidic acid (LPA) is a bioactive phospholipid that signals through a family of at least six G protein-coupled receptors designated LPA₁₋₆. LPA type 1 receptor (LPA₁) exhibits widespread tissue distribution and regulates a variety of physiological and pathological cellular functions. Here, we evaluated the in vitro pharmacology, pharmacokinetic, and pharmacodynamic properties of the LPA₁-selective antagonist AM095 (sodium, {4'-[3-methyl-4-((R)-1-phenyl-ethoxycarbonylamino)-isoxazol-5-yl]-biphenyl-4-yl}-acetate) and assessed the effects of AM095 in rodent models of lung and kidney fibrosis and dermal wound healing. In vitro, AM095 was a potent LPA₁ receptor antagonist because it inhibited GTPγS binding to Chinese hamster ovary (CHO) cell membranes overexpressing recombinant human or mouse LPA₁ with IC₅₀ values of 0.98 and 0.73 μM, respectively, and exhibited no LPA₁ agonism. In functional assays, AM095 inhibited LPA-driven chemotaxis of CHO cells overexpressing mouse LPA₁ (IC₅₀= 778 nM) and human A2058 melanoma cells (IC₅₀ = 233 nM). In vivo, we demonstrated that AM095: 1) had high oral bioavailability and a moderate half-life and was well tolerated at the doses tested in rats and dogs after oral and intravenous dosing, 2) dose-dependently reduced LPA-stimulated histamine release, 3) attenuated bleomycin-induced increases in collagen, protein, and inflammatory cell infiltration in bronchalveolar lavage fluid, and 4) decreased kidney fibrosis in a mouse unilateral ureteral obstruction model. Despite its antifibrotic activity, AM095 had no effect on normal wound healing after incisional and excisional wounding in rats. These data demonstrate that AM095 is an LPA₁ receptor antagonist with good oral exposure and antifibrotic activity in rodent models.
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Comparative Study |
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103 |
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Rubio JP, Stankovich J, Field J, Tubridy N, Marriott M, Chapman C, Bahlo M, Perera D, Johnson LJ, Tait BD, Varney MD, Speed TP, Taylor BV, Foote SJ, Butzkueven H, Kilpatrick TJ. Replication of KIAA0350, IL2RA, RPL5 and CD58 as multiple sclerosis susceptibility genes in Australians. Genes Immun 2008; 9:624-30. [PMID: 18650830 DOI: 10.1038/gene.2008.59] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A recent genome-wide association study (GWAS) conducted by the International Multiple Sclerosis Genetics Consortium (IMSGC) identified a number of putative MS susceptibility genes. Here we have performed a replication study in 1134 Australian MS cases and 1265 controls for 17 risk-associated single nucleotide polymorphisms (SNPs) reported by the IMSGC. Of 16 SNPs that passed quality control filters, four, each corresponding to a different non-human leukocyte antigen (HLA) gene, were associated with disease susceptibility: KIAA0350 (rs6498169) P=0.001, IL2RA (rs2104286) P=0.033, RPL5 (rs6604026) P=0.041 and CD58 (rs12044852) P=0.042. There was no association (P=0.58) between rs6897932 in the IL7R gene and the risk of MS. No interactions were detected between the replicated IMSGC SNPs and HLA-DRB1*15, gender, disease course, disease progression or age-at-onset. We used a novel Bayesian approach to estimate the extent to which our data increased or decreased evidence for association with the six most-associated IMSGC loci. These analyses indicated that even modest P-values, such as those reported here, can contribute markedly to the posterior probability of 'true' association in replication studies. In conclusion, these data provide support for the involvement of four non-HLA genes in the pathogenesis of MS, and combined with previous data, increase to genome-wide significance (P=3 x 10(-8)) evidence of an association between KIAA0350 and risk of disease.
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Research Support, Non-U.S. Gov't |
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101 |
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MacLennan IC, Chapman C, Dunn J, Kelly K. Combined chemotherapy with ABCM versus melphalan for treatment of myelomatosis. The Medical Research Council Working Party for Leukaemia in Adults. Lancet 1992; 339:200-5. [PMID: 1346171 DOI: 10.1016/0140-6736(92)90004-m] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Both melphalan and cyclophosphamide increase life expectancy in patients with myelomatosis, but few large randomised studies have compared combination chemotherapy regimens with these single agents. In the Vth MRC myelomatosis trial, the survival of 314 patients randomised to receive ABCM (adriamycin, BCNU, cyclophosphamide, and melphalan) as first-line treatment was significantly longer than that of 316 patients given intermittent melphalan (M7) (p = 0.0003). The 75%, median, and 25% survivals were 7, 24, and 42 months, respectively, with M7 and 10, 32, and 56 months, respectively, with ABCM. Stable disease with few symptoms (plateau) was achieved by 61% of patients given ABCM and 49% of those given M7 (p = 0.004). Myelotoxicity was comparable between regimens. Cross-trial analysis suggests that M7 is comparable to melphalan and prednisone or melphalan, prednisone, and vincristine; that the efficacy of ABCM in the Vth trial and VIth MRC trials is comparable; and that ABCM gave better survival than intermittent melphalan regimens in the prognostic groups analysed. The results indicate that ABCM is an acceptable regimen that is more effective than melphalan, with or without prednisone, for first-line treatment of myelomatosis.
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Clinical Trial |
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101 |