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Guy SP, Tulwa N. West J Med 2009; 338:b1842-b1842. [DOI: 10.1136/bmj.b1842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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McKillop D, Guy SP, Spence MP, Kendrew J, Kemp JV, Bushby N, Wood PG, Barnett S, Hutchison M. Minimal contribution of desmethyl-gefitinib, the major human plasma metabolite of gefitinib, to epidermal growth factor receptor (EGFR)-mediated tumour growth inhibition. Xenobiotica 2008; 36:29-39. [PMID: 16507511 DOI: 10.1080/00498250500523253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [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: 10/25/2022]
Abstract
Desmethyl-gefitinib is a major metabolite of gefitinib observed in human plasma at concentrations similar to those of gefitinib. The epidermal growth factor receptor (EGFR)-related inhibitory effects of gefitinib and desmethyl-gefitinib have been compared both in vitro, using enzyme kinase assays and tumour cell growth inhibition, and in vivo by assessment of tumour xenografts growth inhibition in the mouse. Both gefitinib (IC(50) = 0.022 microM) and its desmethyl metabolite (0.036 microM) inhibited subcellular EGFR tyrosine kinase activity with a similar potency and selectivity. However, desmethyl-gefitinib (IC(50) = 0.76 microM) was 15 times less active than gefitinib (0.049 microM) against EGF-stimulated KB cell growth in a whole cell assay. Following a preliminary pharmacokinetic study to compare apparent oral bioavailability, gefitinib (75 mg kg(-1)) and desmethyl-gefitinib (150 mg kg(-1)) were administered orally for 15 days to female nude mice bearing LoVo tumour xenografts. Tumour concentrations of gefitinib (AUC = 300 microg h g(-1)) were much higher than those of desmethyl-gefitinib (44.3 microg h g(-1)), although plasma concentrations of gefitinib (48.4 microg h ml(-1)) and desmethyl-gefitinib (39.0 microg h ml(-1)) were quite similar at these dose levels. Gefitinib produced significant tumour growth inhibition throughout the course of the study ultimately resulting in a 50% decrease (compared with controls) by day 15. In contrast, although present at comparable plasma levels, desmethyl-gefitinib had little effect on tumour growth and is, therefore, considered unlikely to contribute significantly to the therapeutic activity of gefitinib in the clinical situation.
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Affiliation(s)
- D McKillop
- AstraZeneca, Alderley Park, Macclesfield, UK.
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Abstract
We set out to determine the prevalence of bacteriuria in elderly patients institutionalised in 10 homes in Northumberland. Single mid-stream urine (MSU) specimens were collected from 161 asymptomatic patients aged 64-101 years. Thirty-four (21%) samples had > 100 white blood cells (WBC/microliter) on microscopy as well as a significant bacteriuria of > 10(8) bacteria/l, being suggestive of a true urinary tract infection. A total of 115(71%) samples had < 100 WBC. Seventy-five (46%) samples could be described as 'contaminated' or 'infection unlikely' but of these only 31 (19.2% of all samples) were reported as 'contaminated' by the laboratory. This study confirms previous work in America to indicate the high level of bacteriuria in institutionalised elderly patients as well as the very high number (46%) who may show bacteriuria but no rise in the number of WBC suggesting contamination only. Nurses and GPs must be very cautious in interpreting MSU results from such patients.
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Abstract
We have investigated a series of FAP patients in the Northwest of England in order to identify and characterise the specific APC mutations. Using SSCP, we found 27 mutations in a total of 50 families investigated. The mutations were predominantly frameshift or nonsense mutations and there were two splice site changes. We have described two patients with severe Gardner's phenotype from different ethnic backgrounds who share the same mutation at codon 1537. Although the frequency of the most common mutation appears low, it is not dissimilar to that reported by other groups.
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Affiliation(s)
- J G Armstrong
- Department of Medical Genetics, St. Mary's Hospital, Manchester, UK
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Frayling IM, Armstrong JG, Davies DR, Evans DG, Guy SP. Appearances can be deceptive: an APC 1893del4 mutation with unusual properities. Mutations in brief no. 171. Online. Hum Mutat 2000; 12:212. [PMID: 10651483] [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: 02/15/2023]
Abstract
During a systematic search for germ-line APC mutations causative of familial adenomatous polyposis, we discovered what appeared to be an insertion mutation while simply checking exon 14PCR products by agarose gel electrophoresis (AGE). On AGE, exon 14PCR product from the known affected member of this family gave two bands: one of normal length, the other retarded on the gel equivalent to an increase in length of some 20-25 bp. Direct sequencing of DNA purified from the two bands gave identical results, and was consistent with amplification from the same two alleles: one wild-type, and the other having an 1893del4 mutation. This suggested that the normal length band on AGE consisted of DNA homoduplexes (normal:normal and mutant:mutant) and the retarded band consisted of DNA heteroduplexes (normal:mutant and mutant:normal). This hypothesis was tested by subjecting purified material from each of the two bands alone to a single cycle of heat denaturation and annealing, which showed that either band was equally capable of regenerating both bands. Because the anomalous migration of the heteroduplexes is observed in the presence of ethidium bromide, it implies that they have a cruciform of cruciform-like structure. This case illustrates the necessity to be aware of anomalous DNA migration and always sequence all putative mutations.
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Affiliation(s)
- I M Frayling
- Colorectal Cancer Unit, Imperial Cancer Research Fund, St Mark's Hospital, Northwick Park, Harrow, HA1 3UJ, UK.
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Abstract
Molecular diagnostics is progressing from low-throughput, heterogeneous, mostly manual technologies to higher throughput, closed-tube, and automated methods. Fluorescence is the favored signaling technology for such assays, and a number of techniques rely on energy transfer between a fluorophore and a proximal quencher molecule. In these methods, dual-labeled probes hybridize to an amplicon and changes in the quenching of the fluorophore are detected. We describe a new technology that is simple to use, gives highly specific information, and avoids the major difficulties of the alternative methods. It uses a primer with an integral tail that is used to probe an extension product of the primer. The probing of a target sequence is thereby converted into a unimolecular event, which has substantial benefits in terms of kinetics, thermodynamics, assay design, and probe reliability.
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Affiliation(s)
- D Whitcombe
- AstraZeneca Diagnostics, Gadbrook Park, Rudheath, Northwich, Cheshire CW9 7RA, UK.
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Grant SC, Guy SP, Lamb WR, Brooks NH, Brenchley PE, Hutchinson IV. Expression of cytokine messenger RNA after heart transplantation: relationship with rejection and serum cytokines. Transplantation 1996; 62:910-6. [PMID: 8878383 DOI: 10.1097/00007890-199610150-00007] [Citation(s) in RCA: 23] [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: 02/02/2023]
Abstract
Different groups of cytokines may initiate or inhibit the rejection process. We used the polymerase chain reaction to study the expression of cytokine mRNA for interleukin (IL)-2, -4, -6 and -10, tumor necrosis factor-alpha, and interferon-gamma in 187 biopsy specimens from 24 human cardiac transplant recipients 5-555 days after transplantation. Cytokine levels in the serum were also measured. Cytokine mRNA was detected in 38.5% of biopsy specimens. IL-10 mRNA was detected more frequently with mild or absent rejection (11.6% in grades 0 and 1 - vs. 1.4% in grades 2 and 3, P=0.01). Up to 90 days after transplantation, IL-2 mRNA was detected more frequently with moderate rejection (13% in grades 2 and 3 vs. 0% in grades 0 and 1, P=0.076), and IL-4 mRNA was detected more frequently with mild or absent rejection (16% in grades 0 and 1 - vs. 0% in grades 2 and 3, P=0.061). More than 90 days after transplantation, IL-2 mRNA was detected more frequently with mild or absent rejection (10% in grades 0 and 1 vs. 0% in grades 2 and 3, P=0.078). Serum IL-4 levels corresponding to biopsy specimens positive for IL-4 mRNA were higher than those corresponding to specimens negative for IL-4 mRNA (59 pg/ml vs. 32 pg/ml medians, P=0.028). Our results suggest that IL-10 and possibly IL-4 (T helper 2 cytokines) may suppress graft rejection, whereas IL-2 (T helper 1 cytokine) may promote cellular rejection. In addition, cytokine profiles may change with length of time after transplantation. The association of elevated serum levels of IL-4 with increased expression of intragraft IL-4 mRNA may suggest release of this cytokine from the graft into the circulation.
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Affiliation(s)
- S C Grant
- Department of Cardiology, Transplant Unit, Wythenshawe Hospital, Manchester, England
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Davies DR, Armstrong JG, Thakker N, Horner K, Guy SP, Clancy T, Sloan P, Blair V, Dodd C, Warnes TW. Severe Gardner syndrome in families with mutations restricted to a specific region of the APC gene. Am J Hum Genet 1995; 57:1151-8. [PMID: 7485167 PMCID: PMC1801370] [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: 01/25/2023] Open
Abstract
Familial adenomatous polyposis (FAP) is associated with a number of extraintestinal manifestations, which include osteomas, epidermoid cysts, and desmoid tumors, often referred to as "Gardner syndrome." Recent studies have suggested that some of the phenotypic features of FAP are dependent on the position of the mutation within the APC gene. In particular, the correlation between congenital hypertrophy of the retinal pigment epithelium (CHRPE) and APC genotype indicates that affected families may be divided into distinct groups. We have investigated the association between the dentoosseous features of GS on dental panoramic radiographs (DPRs) and APC genotype in a regional cohort of FAP families. DPRs were performed on 84 affected individuals from 36 families, and the dento-osseous features of FAP were quantified by a weighted scoring system. Significant DPR abnormalities were present in 69% of affected individuals. The APC gene mutation was identified in 27 of these families, and for statistical analysis these were subdivided into three groups. Group 1 comprised 18 affected individuals from seven families with mutations 5' of exon 9; these families (except one) did not express CHRPE. Groups 2 comprised 38 individuals from 16 families with mutations between exon 9 and codon 1444, all of whom expressed CHRPE. Group 3 comprised 11 individuals from four families with mutations 3' of codon 1444, none of whom expressed CHRPE. Families with mutations 3' of codon 1444 had significantly more lesions on DPRs (P < .001) and appeared to have a higher incidence of desmoid tumors. These results suggest that the severity of some of the features of Gardner syndrome may correlate with genotype in FAP.
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Affiliation(s)
- D R Davies
- Department of Medical Genetics, St. Mary's Hospital, Manchester, United Kingdom
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Connolly JK, Guy SP, Parrott NR. Cytokine gene expression and eicosanoid production in renal reperfusion injury. Transplant Proc 1995; 27:2816-8. [PMID: 7482927] [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] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- J K Connolly
- University Department of Surgery, Manchester Royal Infirmary, United Kingdom
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Joseph JV, Guy SP, Brenchley PE, Parrott NR, Short CD, Johnson RW, Hutchinson IV. Th1 and Th2 cytokine gene expression in human renal allografts. Transplant Proc 1995; 27:915-6. [PMID: 7879228] [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] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- J V Joseph
- Manchester Royal Infirmary, United Kingdom
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Evans DG, Guy SP, Thakker N, Armstrong JG, Dodd C, Davies DR, Babbs C, Clancy T, Warnes T, Sloan P. Non-penetrance and late appearance of polyps in families with familial adenomatous polyposis. Gut 1993; 34:1389-93. [PMID: 8244107 PMCID: PMC1374547 DOI: 10.1136/gut.34.10.1389] [Citation(s) in RCA: 25] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
One case of non-penetrance of the familial adenomatous polyposis (FAP) gene at 59 years of age and late onset of polyps on endoscopy and biopsy in this and two other families is described. Screening protocols should include dental screening as well as indirect ophthalmoscopy and endoscopy to detect minimal manifestations of the gene. In the absence of a specific DNA predictive test, bowel screening should continue well beyond 30 years of age.
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Affiliation(s)
- D G Evans
- Department of Medical Genetics, St Mary's Hospital, Manchester
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Guy SP, Jones D, Mann DM, Itzhaki RF. Human neuroblastoma cells treated with aluminium express an epitope associated with Alzheimer's disease neurofibrillary tangles. Neurosci Lett 1991; 121:166-8. [PMID: 1708474 DOI: 10.1016/0304-3940(91)90676-k] [Citation(s) in RCA: 40] [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] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A number of studies have implicated aluminium as a possible factor in the pathogenesis of Alzheimer's disease (AD). Following an examination of the uptake of aluminium by human neuroblastoma cells in culture, treated with a range of concentrations of aluminium complexed with ethylene-diaminetetra-acetic acid (EDTA), we have now carried out an immunocytochemical study. Using an antibody to phosphorylated tau protein, which reacts specifically with AD neurofibrillary tangles (NFT), we have found that after treatment periods of 16 days to 8 weeks with aluminium-EDTA, the cells show positive staining with this antibody. No such reaction was detected in cells grown in medium alone, nor in aluminium-EDTA-treated cells subjected to the same immunocytochemical procedure but without added primary antibody. Cells grown in medium plus EDTA, which contains a low level of aluminium contamination, showed a slight reaction. Our system may provide a suitable model for studying the early changes which lead to NFT formation.
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Affiliation(s)
- S P Guy
- Department of Optometry and Vision Sciences, UMIST, Manchester, U.K
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Abstract
We have investigated the possibility that the reactivation rate of adult avian erythrocytes, which is slower than that of embryonic erythrocytes, after fusion with metabolically active cells, is due to a greater number of single-strand breaks (ssb) in the DNA of the former. We have assayed ssb by measuring the template activity of the erythrocyte nuclei for added Escherichia coli DNA polymerase. We have found that differences in the numbers of ssb within polymerase-accessible regions between adult and embryonic cells are within experimental error. We conclude that, unless very localized clusters of damage exist within the DNA (which would not be detectable by this or other techniques), the difference in reactivation rate is not attributable to differences in ssb numbers.
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Affiliation(s)
- S P Guy
- Department of Optometry and Vision Sciences, University of Manchester, United Kingdom
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Affiliation(s)
- S P Guy
- Department of Optometry and Vision Sciences, U.M.I.S.T., Manchester, U.K
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Abstract
Avian erythrocytes are terminally differentiated cells but they can be reactivated by fusion with actively metabolising cells. We have examined the effects of treating the erythrocytes with a carcinogenic methylating agent, N-methyl-N-Nitrosourea (MNU), on the process of reactivation of adult and embryonic nuclei. We have found that the rate of nuclear enlargement is slightly lower in nuclei from MNU-treated cells than from control cells and that there is a marked delay of about 24 h in the appearance of nucleoli in both adult and embryonic cells. This is not due to an effect of MNU on ribosomal (r)DNA: the number of rDNA genes appears to be similar in treated and control cells. Also, the number of rDNA genes appears to be similar in adult and embryonic cells and in unreactivated and reactivated embryonic nuclei: thus, differences in reactivation rate between adult and embryonic cells, observed by us and others, can not be attributed to a gross difference in their ribosomal DNA contents, and reappearance of nucleoli on reactivation can not be due to an amplification of rDNA (i.e., to recovery of such genes if lost on terminal differentiation). We suggest that MNU, although a monofunctional alkylating agent, may cause increased association--possibly cross-linkage--between DNA and protein in chromatin, thereby hindering access of host cell reactivating proteins, especially to the nucleolar regions.
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Affiliation(s)
- S P Guy
- Department of Optometry and Vision Sciences, UMIST, Manchester, U.K
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Guy SP, Bradshaw TK, Itzhaki RF. Chromatin characteristics of carcinogen-treated avian erythrocyte nuclei and effects of reactivation. Cell Biol Int Rep 1989; 13:759-71. [PMID: 2805086 DOI: 10.1016/0309-1651(89)90053-2] [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] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have examined nucleosome repeat length and accessibility of erythrocyte nuclei to micrococcal nuclease before and after reactivation of the erythrocytes by fusion with A9 cells, and also after treatment with the alkylating agent N-methyl-N-nitrosourea (MNU). We have found that the repeat length is higher for adult than for embryonic nuclei (227 and 202 base pairs, respectively) and after reactivation the value decreases (to 183 +/- 2 bp and 172 +/- 4 bp, respectively). Values for MNU-treated, reactivated nuclei are slightly (but probably not significantly) higher (188 bp and 176 +/- 1 bp) than for corresponding untreated nuclei. However, the rate of digestion is lower in MNU-treated erythrocytes, both unreactivated and reactivated, than in the corresponding untreated nuclei.
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Affiliation(s)
- S P Guy
- Department of Optometry and Vision Sciences, U.M.I.S.T., Manchester
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