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van Oosterom AT, Judson I, Verweij J, Stroobants S, Donato di Paola E, Dimitrijevic S, Martens M, Webb A, Sciot R, Van Glabbeke M, Silberman S, Nielsen OS. Safety and efficacy of imatinib (STI571) in metastatic gastrointestinal stromal tumours: a phase I study. Lancet 2001; 358:1421-3. [PMID: 11705489 DOI: 10.1016/s0140-6736(01)06535-7] [Citation(s) in RCA: 876] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Gastrointestinal stromal tumours (GISTs) are rare tumours of the gastrointestinal tract characterised by cell-surface expression of the tyrosine kinase KIT (CD117). No effective systemic treatment is available. Imatinib (STI571) inhibits a similar tyrosine kinase, BCR-ABL, leading to responses in chronic myeloid leukaemia, and has also been shown to inhibit KIT. We did a phase I study to identify the dose-limiting toxic effects of imatinib in patients with advanced soft tissue sarcomas including GISTs. METHODS 40 patients (of whom 36 had GISTs) received imatinib at doses of 400 mg once daily, 300 mg twice daily, 400 mg twice daily, or 500 mg twice daily. Toxic effects and haematological, biochemical, and radiological measurements were assessed during 8 weeks of follow-up. 18Fluorodeoxy-glucose positron-emission tomography (PET) was used for response assessment in one centre. FINDINGS Five patients on 500 mg imatinib twice daily had dose-limiting toxic effects (severe nausea, vomiting, oedema, or rash). Inhibition of tumour growth was seen in all but four patients with GISTs, resulting in 19 confirmed partial responses and six as yet unconfirmed partial responses or more than 20% regressions. 24 of 27 clinically symptomatic patients showed improvement, and 29 of 36 were still on treatment after more than 9 months. PET scan responses predicted subsequent computed tomography responses. INTERPRETATION Imatinib at a dose of 400 mg twice daily is well tolerated during the first 8 weeks, side-effects diminish with continuing treatment, and it has significant activity in patients with advanced GISTs. Our results provide evidence of a role for KIT in GISTs, and show the potential for the development of anticancer drugs based on specific molecular abnormalities present in cancers.
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Clinical Trial |
24 |
876 |
2
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Webb A, Cunningham D, Scarffe JH, Harper P, Norman A, Joffe JK, Hughes M, Mansi J, Findlay M, Hill A, Oates J, Nicolson M, Hickish T, O'Brien M, Iveson T, Watson M, Underhill C, Wardley A, Meehan M. Randomized trial comparing epirubicin, cisplatin, and fluorouracil versus fluorouracil, doxorubicin, and methotrexate in advanced esophagogastric cancer. J Clin Oncol 1997; 15:261-7. [PMID: 8996151 DOI: 10.1200/jco.1997.15.1.261] [Citation(s) in RCA: 423] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
PURPOSE We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin, and methotrexate (FAMTX) in previously untreated patients with advanced esophagogastric cancer. PATIENTS AND METHODS Two hundred seventy-four patients with adenocarcinoma or undifferentiated carcinoma were randomized and analyzed for survival, tumor response, toxicity, and quality of life (QL). RESULTS The overall response rate was 45% (95% confidence interval [CI], 36% to 54%) with ECF and 21% (95% CI, 13% to 29%) with FAMTX (P = .0002). Toxicity was tolerable and there were only three toxic deaths. The FAMTX regimen caused more hematologic toxicity and serious infections, but ECF caused more emesis and alopecia. The median survival duration was 8.9 months with ECF and 5.7 months with FAMTX (P = .0009); at 1 year, 36% (95% CI, 27% to 45%) of ECF and 21% (95% CI, 14% to 29%) of FAMTX patients were alive. The median failure-free survival duration was 7.4 months with ECF and 3.4 months with FAMTX (P = .00006). The global QL scores were better for ECF at 24 weeks, but the remaining QL data showed no differences between either arm of the study. Hospital-based cost analysis on a subset of patients was similar for each arm and translated into an increment cost of $975 per life-year gained. CONCLUSION The ECF regimen results in a survival and response advantage, tolerable toxicity, better QL and cost-effectiveness compared with FAMTX chemotherapy. This regimen should now be considered the standard treatment for advanced esophagogastric cancer.
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Clinical Trial |
28 |
423 |
3
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Milham MP, Banich MT, Webb A, Barad V, Cohen NJ, Wszalek T, Kramer AF. The relative involvement of anterior cingulate and prefrontal cortex in attentional control depends on nature of conflict. BRAIN RESEARCH. COGNITIVE BRAIN RESEARCH 2001; 12:467-73. [PMID: 11689307 DOI: 10.1016/s0926-6410(01)00076-3] [Citation(s) in RCA: 418] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
While numerous studies have implicated both anterior cingulate and prefrontal cortex in attentional control, the nature of their involvement remains a source of debate. Here we determine the extent to which their relative involvement in attentional control depends upon the levels of processing at which the conflict occurs (e.g., response, non-response). Using a combination of blocked and rapid presentation event-related functional magnetic resonance imaging techniques, we compared neural activity during incongruent Stroop trial types that produce conflict at different levels of processing. Our data suggest that the involvement of anterior cingulate and right prefrontal cortex in attentional control is primarily limited to situations of response conflict, while the involvement of left prefrontal cortex extends to the occurrence of conflict at non-response levels.
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Clinical Trial |
24 |
418 |
4
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Webb A, Cunningham D, Cotter F, Clarke PA, di Stefano F, Ross P, Corbo M, Dziewanowska Z. BCL-2 antisense therapy in patients with non-Hodgkin lymphoma. Lancet 1997; 349:1137-41. [PMID: 9113013 DOI: 10.1016/s0140-6736(96)11103-x] [Citation(s) in RCA: 372] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Overexpression of BCL-2 is common in non-Hodgkin lymphoma and leads to resistance to programmed cell death (apoptosis) and promotes tumorigenesis. Antisense oligonucleotides targeted at the open reading frame of the BCL-2 mRNA cause a specific down-regulation of BCL-2 expression which leads to increased apoptosis. Lymphoma grown in laboratory animals responds to BCL-2 antisense oligonucleotides with few toxic effects. We report the first study of BCL-2 antisense therapy in human beings. METHODS A daily subcutaneous infusion of 18-base, fully phosporothioated antisense oligonucleotide was administered for 2 weeks to nine patients who had BCL-2-positive relapsed non-Hodgkin lymphoma. Toxicity was scored by the common toxicity criteria, and tumour response was assessed by computed tomography scan. Efficacy was also assessed by quantification of BCL-2 expression; BCL-2 protein levels were measured by flow cytometry in samples from patients. FINDINGS During the course of the study, the daily dose of BCL-2 antisense was increased incrementally from 4.6 mg/m2 to 73.6 mg/m2. No treatment-related toxic effects occurred, apart from local inflammation at the infusion site. In two patients, computed tomography scans showed a reduction in tumour size (one minor, one complete response). In two patients, the number of circulating lymphoma cells decreased during treatment. In four patients, serum concentrations of lactate dehydrogenase fell, and in two of these patients symptoms improved. We were able to measure BCL-2 levels by flow cytometry in the samples of five patients, two of whom had reduced levels of BCL-2 protein. INTERPRETATION In patients with relapsing non-Hodgkin lymphoma, BCL-2 antisense therapy led to an improvement in symptoms, objective biochemical and radiological evidence of tumour response, and down-regulation of the BCL-2 protein in some patients. Our findings are encouraging and warrant further investigations of BCL-2 antisense therapy in cancer treatment.
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Clinical Trial |
28 |
372 |
5
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Waters JS, Webb A, Cunningham D, Clarke PA, Raynaud F, di Stefano F, Cotter FE. Phase I clinical and pharmacokinetic study of bcl-2 antisense oligonucleotide therapy in patients with non-Hodgkin's lymphoma. J Clin Oncol 2000; 18:1812-23. [PMID: 10784621 DOI: 10.1200/jco.2000.18.9.1812] [Citation(s) in RCA: 340] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To evaluate the pharmacokinetics and toxicity of an antisense oligonucleotide targeting bcl-2 in patients with non-Hodgkin's lymphoma (NHL) and to determine efficacy using clinical and biologic end points. PATIENTS AND METHODS Twenty-one patients with Bcl-2-positive relapsed NHL received a 14-day subcutaneous infusion of G3139, an 18-mer phosphorothioate oligonucleotide complementary to the first six codons of the bcl-2 open reading frame. Plasma pharmacokinetics were measured by anion exchange high-performance liquid chromatography. Response was assessed by computed tomography. Changes in Bcl-2 expression were measured by fluorescence-activated cell sorting of patients' tumor samples. RESULTS Eight cohorts of patients received doses between 4. 6 and 195.8 mg/m(2)/d. No significant systemic toxicity was seen at doses up to 110.4 mg/m(2)/d. All patients displayed skin inflammation at the subcutaneous infusion site. Dose-limiting toxicities were thrombocytopenia, hypotension, fever, and asthenia. The maximum-tolerated dose was 147.2 mg/m(2)/d. Plasma levels of G3139 equivalent to the efficacious plasma concentration in in vivo models were produced with doses above 36.8 mg/m(2)/d. Plasma levels associated with dose-limiting toxicity were greater than 4 microg/mL. By standard criteria, there was one complete response, 2 minor responses, nine cases of stable disease, and nine cases of progressive disease. Bcl-2 protein was reduced in seven of 16 assessable patients. This reduction occurred in tumor cells derived from lymph nodes in two patients and from peripheral blood or bone marrow mononuclear cell populations in the remaining five patients. CONCLUSION Bcl-2 antisense therapy is feasible and shows potential for antitumor activity in NHL. Downregulation of Bcl-2 protein suggests a specific antisense mechanism.
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Clinical Trial |
25 |
340 |
6
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Burton GW, Webb A, Ingold KU. A mild, rapid, and efficient method of lipid extraction for use in determining vitamin E/lipid ratios. Lipids 1985; 20:29-39. [PMID: 3968987 DOI: 10.1007/bf02534359] [Citation(s) in RCA: 316] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A new, general method for lipid extraction and measurement of vitamin E/total lipid ratios in tissue and cell samples has been developed. The new extraction procedure uses a combination of sodium dodecylsulfate, ethanol and n-heptane, and is mild, clean, convenient, efficient and rapid (less than or equal to 5 min). The efficiency of the new method has been confirmed for human plasma, red blood cells and rat liver homogenate by the comparison of the yields of vitamin E, O-acyl lipid and cholesterol with the yields obtained following conventional extraction procedures. Extraction efficiency also has been confirmed for multilamellar vesicles composed of known quantities of vitamin E, egg lecithin and cholesterol.
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40 |
316 |
7
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Ward MJ, Thirdborough SM, Mellows T, Riley C, Harris S, Suchak K, Webb A, Hampton C, Patel NN, Randall CJ, Cox HJ, Jogai S, Primrose J, Piper K, Ottensmeier CH, King EV, Thomas GJ. Tumour-infiltrating lymphocytes predict for outcome in HPV-positive oropharyngeal cancer. Br J Cancer 2014; 110:489-500. [PMID: 24169344 PMCID: PMC3899750 DOI: 10.1038/bjc.2013.639] [Citation(s) in RCA: 312] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/28/2013] [Accepted: 09/12/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Human papillomavirus (HPV)-positive oropharyngeal cancer (OPSCC) is associated with improved survival compared with HPV-negative disease. However, a minority of HPV-positive patients have poor prognosis. Currently, there is no generally accepted strategy for identifying these patients. METHODS We retrospectively analysed 270 consecutively treated OPSCC patients from three centres for effects of clinical, pathological, immunological, and molecular features on disease mortality. We used Cox regression to examine associations between factors and OPSCC death, and developed a prognostic model for 3-year mortality using logistic regression analysis. RESULTS Patients with HPV-positive tumours showed improved survival (hazard ratio (HR), 0.33 (0.21-0.53)). High levels of tumour-infiltrating lymphocytes (TILs) stratified HPV-positive patients into high-risk and low-risk groups (3-year survival; HPV-positive/TIL(high)=96%, HPV-positive/TIL(low)=59%). Survival of HPV-positive/TIL(low) patients did not differ from HPV-negative patients (HR, 1.01; P=0.98). We developed a prognostic model for HPV-positive tumours using a 'training' cohort from one centre; the combination of TIL levels, heavy smoking, and T-stage were significant (AUROC=0·87). This model was validated on patients from the other centres (detection rate 67%; false-positive rate 5.6%; AUROC=0·82). INTERPRETATION Our data suggest that an immune response, reflected by TIL levels in the primary tumour, has an important role in the improved survival seen in most HPV-positive patients, and is relevant for the clinical evaluation of HPV-positive OPSCC.
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Multicenter Study |
11 |
312 |
8
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Banich MT, Milham MP, Atchley R, Cohen NJ, Webb A, Wszalek T, Kramer AF, Liang ZP, Wright A, Shenker J, Magin R. fMri studies of Stroop tasks reveal unique roles of anterior and posterior brain systems in attentional selection. J Cogn Neurosci 2000; 12:988-1000. [PMID: 11177419 DOI: 10.1162/08989290051137521] [Citation(s) in RCA: 309] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The brain's attentional system identifies and selects information that is task-relevant while ignoring information that is task-irrelevant. In two experiments using functional magnetic resonance imaging, we examined the effects of varying task-relevant information compared to task-irrelevant information. In the first experiment, we compared patterns of activation as attentional demands were increased for two Stroop tasks that differed in the task-relevant information, but not the task-irrelevant information: a color-word task and a spatial-word task. Distinct subdivisions of dorsolateral prefrontal cortex and the precuneus became activated for each task, indicating differential sensitivity of these regions to task-relevant information (e.g., spatial information vs. color). In the second experiment, we compared patterns of activation with increased attentional demands for two Stroop tasks that differed in task-irrelevant information, but not task-relevant information: a color-word task and color-object task. Little differentiation in activation for dorsolateral prefrontal and precuneus regions was observed, indicating a relative insensitivity of these regions to task-irrelevant information. However, we observed a differentiation in the pattern of activity for posterior regions. There were unique areas of activation in parietal regions for the color-word task and in occipitotemporal regions for the color-object task. No increase in activation was observed in regions responsible for processing the perceptual attribute of color. The results of this second experiment indicate that attentional selection in tasks such as the Stroop task, which contain multiple potential sources of relevant information (e.g., the word vs. its ink color), acts more by modulating the processing of task-irrelevant information than by modulating processing of task-relevant information.
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Clinical Trial |
25 |
309 |
9
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Webb A, Cunningham D, Scarffe JH, Harper P, Norman A, Joffe JK, Hughes M, Mansi J, Findlay M, Hill A, Oates J, Nicolson M, Hickish T, O'Brien M, Iveson T, Watson M, Underhill C, Wardley A, Meehan M. Randomized trial comparing epirubicin, cisplatin, and fluorouracil versus fluorouracil, doxorubicin, and methotrexate in advanced esophagogastric cancer. J Clin Oncol 1997. [PMID: 8996151 DOI: 10.1016/s0959-8049(97)86090-x] [Citation(s) in RCA: 306] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
PURPOSE We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin, and methotrexate (FAMTX) in previously untreated patients with advanced esophagogastric cancer. PATIENTS AND METHODS Two hundred seventy-four patients with adenocarcinoma or undifferentiated carcinoma were randomized and analyzed for survival, tumor response, toxicity, and quality of life (QL). RESULTS The overall response rate was 45% (95% confidence interval [CI], 36% to 54%) with ECF and 21% (95% CI, 13% to 29%) with FAMTX (P = .0002). Toxicity was tolerable and there were only three toxic deaths. The FAMTX regimen caused more hematologic toxicity and serious infections, but ECF caused more emesis and alopecia. The median survival duration was 8.9 months with ECF and 5.7 months with FAMTX (P = .0009); at 1 year, 36% (95% CI, 27% to 45%) of ECF and 21% (95% CI, 14% to 29%) of FAMTX patients were alive. The median failure-free survival duration was 7.4 months with ECF and 3.4 months with FAMTX (P = .00006). The global QL scores were better for ECF at 24 weeks, but the remaining QL data showed no differences between either arm of the study. Hospital-based cost analysis on a subset of patients was similar for each arm and translated into an increment cost of $975 per life-year gained. CONCLUSION The ECF regimen results in a survival and response advantage, tolerable toxicity, better QL and cost-effectiveness compared with FAMTX chemotherapy. This regimen should now be considered the standard treatment for advanced esophagogastric cancer.
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Randomized Controlled Trial |
28 |
306 |
10
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Toronov V, Webb A, Choi JH, Wolf M, Michalos A, Gratton E, Hueber D. Investigation of human brain hemodynamics by simultaneous near-infrared spectroscopy and functional magnetic resonance imaging. Med Phys 2001; 28:521-7. [PMID: 11339749 DOI: 10.1118/1.1354627] [Citation(s) in RCA: 275] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The aim of this study was to compare functional cerebral hemodynamic signals obtained simultaneously by near infrared spectroscopy (NIRS) and by functional magnetic resonance imaging (fMRI). The contribution of superficial layers (skin and skull) to the NIRS signal was also assessed. Both methods were used to generate functional maps of the motor cortex area during a periodic sequence of stimulation by finger motion and rest. In all subjects we found a good collocation of the brain activity centers revealed by both methods. We also found a high temporal correlation between the BOLD signal (fMRI) and the deoxy-hemoglobin concentration (NIRS) in the subjects who exhibited low fluctuations in superficial head tissues.
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Comparative Study |
24 |
275 |
11
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Banich MT, Milham MP, Atchley RA, Cohen NJ, Webb A, Wszalek T, Kramer AF, Liang Z, Barad V, Gullett D, Shah C, Brown C. Prefrontal regions play a predominant role in imposing an attentional 'set': evidence from fMRI. BRAIN RESEARCH. COGNITIVE BRAIN RESEARCH 2000; 10:1-9. [PMID: 10978687 DOI: 10.1016/s0926-6410(00)00015-x] [Citation(s) in RCA: 251] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
fMRI was used to determine whether prefrontal regions play a predominant role in imposing an attentional 'set' that drives selection of task-relevant information. While monitoring for an atypical item, individuals viewed Stroop stimuli that were either colored words or colored objects. Attentional demands were varied, being greater when the stimuli contained two distinct and incongruent sources of information about the task-relevant attribute (e.g., when attending to color, seeing the word 'blue' in red ink) as compared to only one source (e.g., seeing the word 'late' in red ink). Prefrontal but not anterior cingulate regions exhibited greater activation on incongruent than neutral trials, suggesting that prefrontal cortex has a major role in imposing an attentional 'set'. In addition, we found that prefrontal activation is most likely to occur when that attentional set is difficult to impose.
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25 |
251 |
12
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Waters JS, Norman A, Cunningham D, Scarffe JH, Webb A, Harper P, Joffe JK, Mackean M, Mansi J, Leahy M, Hill A, Oates J, Rao S, Nicolson M, Hickish T. Long-term survival after epirubicin, cisplatin and fluorouracil for gastric cancer: results of a randomized trial. Br J Cancer 1999; 80:269-72. [PMID: 10390007 PMCID: PMC2363002 DOI: 10.1038/sj.bjc.6690350] [Citation(s) in RCA: 217] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We report the final results of a prospectively randomized study that compared the combination of epirubicin, cisplatin and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin and methotrexate (FAMTX) in previously untreated patients with advanced oesophagogastric cancer. Between 1992 and 1995, 274 patients with adenocarcinoma or undifferentiated carcinoma were randomized from eight oncology centres in the UK and analysed for response and survival. The overall response rate was 46% (95% confidence interval (CI), 37-55%) with ECF, and 21% (95% CI, 13-28%) with FAMTX (P = 0.00003). The median survival was 8.7 months with ECF and 6.1 months with FAMTX (P = 0.0005). The 2-year survival rates were 14% (95% CI, 8-20%) for the ECF arm, and 5% (95% CI, 2-10%) for the FAMTX arm (P = 0.03). Histologically complete surgical resection following chemotherapy was achieved in ten patients in the ECF arm (three pathological complete responses to chemotherapy) and three patients in the FAMTX arm (no pathological complete responses). The ECF regimen resulted in a response and survival advantage compared with FAMTX chemotherapy. The probability of long-term survival following surgical resection of residual disease is increased by this treatment. The high response rates seen with ECF support its use in the neoadjuvant setting.
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research-article |
26 |
217 |
13
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Mergaert J, Webb A, Anderson C, Wouters A, Swings J. Microbial degradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in soils. Appl Environ Microbiol 1993; 59:3233-8. [PMID: 8250550 PMCID: PMC182442 DOI: 10.1128/aem.59.10.3233-3238.1993] [Citation(s) in RCA: 204] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The microbial degradation of tensile test pieces made of poly(3-hydroxybutyrate) [P(3HB)] or a copolymer of 90% 3-hydroxybutyric acid and 10% 3-hydroxyvaleric acid was studied in soils incubated at a constant temperature of 15, 28, or 40 degrees C for up to 200 days. In addition, hydrolytic degradation in sterile buffer at temperatures ranging from 4 to 55 degrees C was monitored for 98 days. Degradation was measured through loss of weight (surface erosion), molecular weight, and mechanical strength. While no weight loss was recorded in sterile buffer, samples incubated in soils were degraded at an erosion rate of 0.03 to 0.64% weight loss per day, depending on the polymer, the soil, and the incubation temperature. The erosion rate was enhanced by incubation at higher temperatures, and in most cases the copolymer lost weight at a higher rate than the homopolymer. The molecular weights of samples incubated at 40 degrees C in soils and those incubated at 40 degrees C in sterile buffer decreased at similar rates, while the molecular weights of samples incubated at lower temperatures remained almost unaffected, indicating that molecular weight decrease is due to simple hydrolysis and not to the action of biodegrading microorganisms. The degradation resulted in loss of mechanical properties. From the samples used in the biodegradation studies, 295 dominant microbial strains capable of degrading P (3HB) and the poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer in vitro were isolated and identified.(ABSTRACT TRUNCATED AT 250 WORDS)
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research-article |
32 |
204 |
14
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Compston JE, Vedi S, Ledger JE, Webb A, Gazet JC, Pilkington TR. Vitamin D status and bone histomorphometry in gross obesity. Am J Clin Nutr 1981; 34:2359-63. [PMID: 7304477 DOI: 10.1093/ajcn/34.11.2359] [Citation(s) in RCA: 189] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Plasma 25-hydroxyvitamin D concentrations and bone histomorphometry were investigated in 24 grossly obese subjects. The mean plasma 25OHD concentration was significantly lower in the obese group than in age-matched, healthy controls. Subnormal values were found in four obese subjects and in a further two subjects, who were investigated at the end of the summer, plasma 25-hydroxyvitamin D levels were at the lower end of the normal winter range. Bone histology was abnormal in two patients. In one, mild osteomalacia and secondary hyperparathyroidism were present while in the other patient the appearance suggested increased bone turnover, possibly as a result of healing osteomalacia. We conclude that gross obesity is associated with an increased risk of vitamin D deficiency, probably because of reduced exposure to uv radiation. Histological evidence of metabolic bone disease may also occur. Preoperative vitamin D deficiency may contribute in some patients to the development of metabolic bone disease after intestinal bypass.
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44 |
189 |
15
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Ingold KU, Burton GW, Foster DO, Hughes L, Lindsay DA, Webb A. Biokinetics of and discrimination between dietary RRR- and SRR-alpha-tocopherols in the male rat. Lipids 1987; 22:163-72. [PMID: 3573996 DOI: 10.1007/bf02537297] [Citation(s) in RCA: 179] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The net rates of uptake of the natural (2R,4'R,8'R) diastereoisomer of alpha-tocopherol (alpha-T) and the biodiscrimination relative to its 2S-epimer (2S,4'R,8'R) have been measured, in two experiments, for the blood and 21 tissues of male Sprague-Dawley rats fed over a period of several months diets containing deuterium-substituted forms of the alpha-T acetates. Gas chromatography-mass spectrometry was used to measure the amount of deuterated tocopherols taken up relative to the amount of nondeuterated tocopherol remaining. The measurements were performed at different times after the rats, placed for one month on a basal diet containing nondeuterated, natural alpha-T acetate, were switched to a diet containing the same total quantity of deuterated forms of either natural alpha-T acetate or a mixture of the acetates of the 2R- and 2S-epimers (i.e., ambo-alpha-T acetate). In experiment 1 the source of vitamin E in the replacement diet was trideuterio-2R,4'R,8'R-alpha-T acetate. The data obtained provide the first direct measure of the rate at which natural vitamin E is replaced and augmented in the tissues of growing animals under normal laboratory dietary conditions. There are dramatic differences in the tissue kinetics; for example, the apparent half-life of vitamin E, i.e., the time at which the total amount of ingested trideuterio-alpha-T taken up is the same as the amount of nondeuterated alpha-T remaining, varies from ca. 1 wk for the lung to ca. 11 wk for the spinal cord. In experiment 2 the vitamin E in the replacement diet was an equimolar mixture of trideuterio-2S,4'R,8'R- and hexadeuterio-2R,4'R,8'R-alpha-T acetates. The results show that there is a preferential uptake of the natural diastereoisomer of alpha-T by all tissues (except the liver during the first month). Examination of fecal material reveals that the biodiscrimination begins in the gut; the incomplete hydrolysis of the acetates shows clearly that this reaction proceeds to a greater extent with the natural diastereoisomer. The greatest discrimination of all the tissues examined was found to occur in the brain. After five months, the level of the deuterated natural diastereoisomer was more than five times that of the deuterated 2S-epimer. These results have potential implications for human nutrition.
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Comparative Study |
38 |
179 |
16
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DiGirolamo GJ, Kramer AF, Barad V, Cepeda NJ, Weissman DH, Milham MP, Wszalek TM, Cohen NJ, Banich MT, Webb A, Belopolsky AV, McAuley E. General and task-specific frontal lobe recruitment in older adults during executive processes: a fMRI investigation of task-switching. Neuroreport 2001; 12:2065-71. [PMID: 11435947 DOI: 10.1097/00001756-200107030-00054] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Performance deteriorates when subjects must shift between two different tasks relative to performing either task separately. This switching cost is thought to result from executive processes that are not inherent to the component operations of either task when performed alone. Medial and dorsolateral frontal cortices are theorized to subserve these executive processes. Here we show that larger areas of activation were seen in dorsolateral and medial frontal cortex in both younger and older adults during switching than repeating conditions, confirming the role of these frontal brain regions in executive processes. Younger subjects activated these medial and dorsolateral frontal cortices only when switching between tasks; in contrast, older subjects recruited similar frontal regions while performing the tasks in isolation as well as alternating between them. Older adults recruit medial and dorsolateral frontal areas, and the processes computed by these areas, even when no such demands are intrinsic to the current task conditions. This neural recruitment may be useful in offsetting the declines in cognitive function associated with ageing.
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24 |
165 |
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Chau I, Norman AR, Cunningham D, Tait D, Ross PJ, Iveson T, Hill M, Hickish T, Lofts F, Jodrell D, Webb A, Oates JR. A randomised comparison between 6 months of bolus fluorouracil/leucovorin and 12 weeks of protracted venous infusion fluorouracil as adjuvant treatment in colorectal cancer. Ann Oncol 2005; 16:549-57. [PMID: 15695501 DOI: 10.1093/annonc/mdi116] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND We performed a multicentre randomised trial to compare the efficacy and toxicity of 12 weeks of protracted venous infusion (PVI) 5-fluorouracil (5-FU) against the standard bolus monthly regimen of 5-FU/leucovorin (LV) given for 6 months as adjuvant treatment in colorectal cancer (CRC). PATIENTS AND METHODS Patients with curatively resected stage II and III CRC were randomly assigned to 5-FU/LV [5-FU 425 mg/m(2) intravenously (i.v.) and LV 20 mg/m(2) i.v. bolus days 1-5 every 28 days for 6 months] or to PVI 5-FU (300 mg/m(2)/day for 12 weeks). RESULTS Between 1993 and 2003, 801 eligible patients were randomised to 5-FU/LV (n=404) or PVI 5-FU (n=397). With a median follow-up of 5.3 years, 231 relapses and 220 deaths have been observed. Five-year relapse-free survival (RFS) was 66.7% [95% confidence interval (CI) 61.6% to 71.3%] and 73.3% (95% CI 68.4% to 77.6%) with bolus 5-FU/LV and PVI 5-FU, respectively [hazard ratio (HR) 0.8; 95% CI 0.62-1.04; P=0.10]. Five-year overall survival (OS) was 71.5% (95% CI 66.4% to 75.9%) and 75.7% (95% CI 70.8% to 79.9%) with bolus 5-FU/LV and PVI 5-FU, respectively (HR 0.79; 95% CI 0.61-1.03; P=0.083). There was a significant survival advantage for patients starting adjuvant chemotherapy within 8 weeks (P=0.044). Significantly less diarrhoea, stomatitis, nausea and vomiting, alopecia, lethargy, and neutropenia (all with P <0.0001) were seen with PVI 5-FU. CONCLUSIONS There was no OS difference between the two arms, although PVI 5-FU was associated with a trend towards better RFS and OS compared with bolus 5-FU/LV, as well as significantly less toxicity. Based on our results, the probability of 12 weeks of PVI 5-FU being inferior to 6 months of bolus 5-FU/LV is extremely low (P <0.005), and therefore shorter duration of adjuvant treatment should be explored further.
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Randomized Controlled Trial |
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139 |
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Veprek S, Iqbal Z, Oswald HR, Webb AP. Properties of polycrystalline silicon prepared by chemical transport in hydrogen plasma at temperatures between 80 and 400 degrees C. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/14/3/013] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25 |
132 |
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Ross P, Norman A, Cunningham D, Webb A, Iveson T, Padhani A, Prendiville J, Watson M, Massey A, Popescu R, Oates J. A prospective randomised trial of protracted venous infusion 5-fluorouracil with or without mitomycin C in advanced colorectal cancer. Ann Oncol 1997; 8:995-1001. [PMID: 9402173 DOI: 10.1023/a:1008263516099] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND To compare protracted venous infusion (PVI) 5-fluorouracil (5-FU) with and without mitomycin C (MMC) in a prospectively randomised study and analyse for tumour response, survival, toxicity and quality of life (QL). PATIENTS AND METHODS Two hundred patients with advanced colorectal cancer received PVI 5-FU 300 mg/m2/day for a maximum of 24 weeks and were randomised to PVI 5-FU alone or PVI 5-FU + MMC 10 mg/m2 (7 mg/m2 from June 1995) 6 weekly for 4 courses. RESULTS Overall response was 54% (95% confidence interval [CI] 44.1%-63.9%) with PVI 5-FU + MMC compared to 38% (95% CI: 28.3%-47.7%) for PVI 5-FU alone (P = 0.024). The median failure free survival was 7.9 months in PVI 5-FU plus MMC and 5.4 months with PVI 5-FU alone (P = 0.033) and at one year 31.9% for the combination compared to 17.7% for PVI 5-FU alone. Median survival was 14 months with MMC and 15 months in 5-FU alone; one-year survival 51.7% vs. 57.2%. PVI 5-FU + MMC caused more overall haematological toxicity but CTC grades 3/4 was increased only for thrombocytopaenia. Two patients treated with a cumulative dose of MMC of 40 mg/m2 developed haemolytic uraemic syndrome warranting the reduction in cumulative MMC dose to 28 mg/m2. The global QL scores were better for PVI 5-FU + MMC arm at 24 weeks, but the remaining QL data showed no differences. CONCLUSIONS PVI 5-FU + MMC results in failure-free survival and response advantage, tolerable toxicity and better QL when compared to PVI 5-FU alone but no overall survival advantage. There is no irreversible toxicity with MMC at a cumulative dose of 28 mg/m2.
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Clinical Trial |
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111 |
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Abstract
To determine whether bone loss in patients with chronic cholestatic liver disease is the consequence of a high or low bone turnover state, 30 female patients with biopsy-proven primary biliary cirrhosis underwent iliac crest biopsy following double tetracycline labeling. The mean trabecular bone volume was decreased as a result of trabecular plate thinning in both the premenopausal (p less than 0.02) and postmenopausal (p less than 0.05) patients, compared to age- and sex-matched controls. Indications that osteoblastic function was impaired included a significantly lower mean wall thickness (p less than 0.01) and mean osteoid seam width (p less than 0.05), and this in association with a decreased mineral appositional rate and prolonged mineralization lag time was suggestive of a defect in matrix synthesis. Further evidence of impaired osteoblastic activity was the significantly lower bone formation rate at both tissue (p less than 0.001) and basic multicellular unit levels (p less than 0.05) in the postmenopausal patients. Total resorption surfaces and fasting urinary calcium/creatinine ratios were significantly increased (p less than 0.005 and 0.05, respectively) in the premenopausal patients and mean interstitial bone thickness reduced in both pre- and postmenopausal patients, suggesting that increased resorption may also contribute to bone loss in primary biliary cirrhosis.
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38 |
108 |
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Vedi S, Compston JE, Webb A, Tighe JR. Histomorphometric analysis of dynamic parameters of trabecular bone formation in the iliac crest of normal British subjects. METABOLIC BONE DISEASE & RELATED RESEARCH 1983; 5:69-74. [PMID: 6672539 DOI: 10.1016/0221-8747(83)90004-8] [Citation(s) in RCA: 105] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Some dynamic parameters of bone formation in trabecular iliac crest bone have been measured in a group of normal British subjects of both sexes over a wide age range. There was a significant age-related decrease in mean wall thickness. When either double plus single or double only tetracycline-labeled surfaces were used to represent actively mineralizing surfaces, there was a significant age-related decrease in the bone formation rate at the basic multicellular unit level. Osteoid maturation period showed a significant age-related increase when calculated using double plus single labeled surfaces. There was no significant change with age in fractional labeled surfaces, mean osteoid seam width, bone formation rate at tissue level, or bone formation period. The mean osteoid seam width and osteoid maturation period were significantly higher in males than in females.
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Comparative Study |
42 |
105 |
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Vedi S, Compston JE, Webb A, Tighe JR. Histomorphometric analysis of bone biopsies from the iliac crest of normal British subjects. METABOLIC BONE DISEASE & RELATED RESEARCH 1982; 4:231-6. [PMID: 7182722 DOI: 10.1016/0221-8747(82)90032-7] [Citation(s) in RCA: 99] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Bone histomorphometric parameters have been measured in a group of normal British subjects of both sexes over a wide age range. There is loss of trabecular mineralized bone volume with advancing age and an increase in osteoid volume and in the trabecular bone surface covered by osteoid seams. There was no change in the mineral appositional rate or in bone resorption surfaces.
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43 |
99 |
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Bower M, Collins S, Cottrill C, Cwynarski K, Montoto S, Nelson M, Nwokolo N, Powles T, Stebbing J, Wales N, Webb A. British HIV Association guidelines for HIV-associated malignancies 2008. HIV Med 2009; 9:336-88. [PMID: 18705759 DOI: 10.1111/j.1468-1293.2008.00608.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Practice Guideline |
16 |
96 |
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Geier EG, Chen EC, Webb A, Papp AC, Yee SW, Sadee W, Giacomini KM. Profiling solute carrier transporters in the human blood-brain barrier. Clin Pharmacol Ther 2013; 94:636-9. [PMID: 24013810 PMCID: PMC3906042 DOI: 10.1038/clpt.2013.175] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 08/22/2013] [Indexed: 11/15/2022]
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Research Support, U.S. Gov't, P.H.S. |
12 |
95 |
25
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Maisey NR, Webb A, Flux GD, Padhani A, Cunningham DC, Ott RJ, Norman A. FDG-PET in the prediction of survival of patients with cancer of the pancreas: a pilot study. Br J Cancer 2000; 83:287-93. [PMID: 10917540 PMCID: PMC2374572 DOI: 10.1054/bjoc.2000.1166] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Carcinoma of the pancreas is an aggressive tumour with an extremely poor prognosis. Recent studies have shown that chemotherapy can improve survival as well as quality of life. Since the prognosis is generally poor, the identification of early responders to chemotherapy is important to avoid unnecessary toxicity in patients who are not responding. Response assessment by conventional radiographic methods is problematical because treatment induces fibrosis and makes tumour measurements difficult. The aim of this pilot study was to assess 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET) as an early marker of the benefit of chemotherapy. Eleven patients with histologically proven adenocarcinoma of the pancreas were treated with protracted venous infusional 5-fluorouracil (PVI 5-FU) alone or PVI 5-FU and mitomycin C (MMC). FDG-PET scans were performed prior to and at 1 month following the commencement of chemotherapy. FDG uptake was compared with the tumour dimensions measured on a computer tomographic (CT) scan. Patients were followed up for relapse, death and symptomatic response. Three of the 11 patients had no measurable FDG uptake prior to chemotherapy. Of the eight patients who had measurable uptake prior to treatment, seven had a reduction in uptake at 1 month. Six out of the 11 patients had no measurable FDG uptake at 1 month. The overall survival (OS) in these patients ranged from 124 to 1460 days, with a median of 318.5 days. This was superior in comparison to patients who had residual FDG uptake at 1 month (median survival 318.5 days vs 139 days; P = 0.034) and there was a trend to improved symptoms (84% [5/6] vs 20% [1/5]; P = 0.13). There was no statistically significant correlation between best CT response and FDG uptake at 1 month. These results suggest that the absence of FDG uptake at 1 month following chemotherapy for carcinoma of the pancreas is an indicator of improved overall survival. This suggests that FDG-PET may be superior to response assessment by conventional radiographic methods and FDG-PET may have the potential to help make difficult treatment decisions in the management of pancreatic cancer. Larger prospective studies are required to confirm this finding.
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research-article |
25 |
95 |