20 results on '"Chakiath C"'
Search Results
2. Escalated-dose versus control-dose conformal radiotherapy for prostate cancer: long-term results from the MRC RT01 randomised controlled trial
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Dearnaley, David P, Jovic, Gordana, Syndikus, Isabel, Khoo, Vincent, Cowan, Richard A, Graham, John D, Aird, Edwin G, Bottomley, David, Huddart, Robert A, Jose, Chakiath C, Matthews, John H L, Millar, Jeremy L, Murphy, Claire, Russell, J Martin, Scrase, Christopher D, Parmar, Mahesh K B, and Sydes, Matthew R
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- 2014
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3. Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial
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Dearnaley, David P, Sydes, Matthew R, Graham, John D, Aird, Edwin G, Bottomley, David, Cowan, Richard A, Huddart, Robert A, Jose, Chakiath C, Matthews, John HL, Millar, Jeremy, Moore, A Rollo, Morgan, Rachel C, Russell, J Martin, Scrase, Christopher D, Stephens, Richard J, Syndikus, Isabel, and Parmar, Mahesh KB
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- 2007
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4. The early toxicity of escalated versus standard dose conformal radiotherapy with neo-adjuvant androgen suppression for patients with localised prostate cancer: Results from the MRC RT01 trial (ISRCTN47772397)
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Dearnaley, David P., Sydes, Matthew R., Langley, Ruth E., Graham, John D., Huddart, Robert A., Syndikus, Isabel, Matthews, John H.L., Scrase, Christopher D., Jose, Chakiath C., Logue, John, and Stephens, Richard J.
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- 2007
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5. A Phase III trial to investigate the timing of radiotherapy for prostate cancer with high-risk features: background and rationale of the Radiotherapy - Adjuvant Versus Early Salvage (RAVES) trial
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David Joseph, Henry H. Woo, Chakiath C Jose, John H L Matthews, Jeremy Millar, Gillian M. Duchesne, Scott Williams, Colin Tang, Carol Fraser-Browne, Andrew Kneebone, Annette Haworth, Sandra Turner, Teesin Lim, Mark Frydenberg, Ian D. Davis, K. Wiltshire, Nigel Spry, Richard Fisher, Maria Pearse, and Mark Sidhom
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Oncology ,medicine.medical_specialty ,business.industry ,Prostatectomy ,Urology ,medicine.medical_treatment ,Salvage therapy ,medicine.disease ,law.invention ,Surgery ,Quality-adjusted life year ,Clinical trial ,Radiation therapy ,Prostate cancer ,Prostate-specific antigen ,Randomized controlled trial ,law ,Internal medicine ,medicine ,business - Abstract
Objectives To test the hypothesis that observation with early salvage radiotherapy (SRT) is not inferior to ‘standard’ treatment with adjuvant RT (ART) with respect to biochemical failure in patients with pT3 disease and/or positive surgical margins (SMs) after radical prostatectomy (RP). To compare the following secondary endpoints between the two arms: patient-reported outcomes, adverse events, biochemical failure-free survival, overall survival, disease-specific survival, time to distant failure, time to local failure, cost utility analysis, quality adjusted life years and time to androgen deprivation. Patients and Methods The Radiotherapy – Adjuvant Versus Early Salvage (RAVES) trial is a phase III multicentre randomised controlled trial led by the Trans Tasman Radiation Oncology Group (TROG), in collaboration with the Urological Society of Australia and New Zealand (USANZ), and the Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP). In all, 470 patients are planned to be randomised 1:1 to either ART commenced at ≤4 months of RP (standard of care) or close observation with early SRT triggered by a PSA level of >0.20 ng/mL (experimental arm). Eligible patients have had a RP for adenocarcinoma of the prostate with at least one of the following risk factors: positive SMs ± extraprostatic extension ± seminal vesicle involvement. The postoperative PSA level must be ≤0.10 ng/mL. Rigorous investigator credentialing and a quality assurance programme are designed to promote consistent RT delivery among patients. Results Trial is currently underway, with 258 patients randomised as of 31 October 2013. International collaborations have developed, including a planned meta-analysis to be undertaken with the UK Medical Research Council/National Cancer Institute of Canada Clinical Trials Group RADICALS (Radiotherapy and Androgen Deprivation In Combination with Local Surgery) trial and an innovative psycho-oncology sub-study to investigate a patient decision aid resource. Conclusion On the current evidence available, it remains unclear if ART is equivalent or superior to observation with early SRT.
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- 2014
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6. Escalated-dose versus standard-dose conformal radiotherapy in prostate cancer: first results from the MRC RT01 randomised controlled trial
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Richard A Cowan, Mahesh K. B. Parmar, Robert Huddart, John Graham, J. Martin Russell, Richard Stephens, John H L Matthews, Christopher D Scrase, Matthew R. Sydes, David P. Dearnaley, A. Rollo Moore, Rachel C Morgan, Edwin Aird, Jeremy Millar, Chakiath C Jose, Isabel Syndikus, and David Bottomley
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Male ,Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,Androgen suppression ,Disease-Free Survival ,law.invention ,Prostate cancer ,Randomized controlled trial ,law ,Internal medicine ,medicine ,Humans ,External beam radiotherapy ,Aged ,Intention-to-treat analysis ,business.industry ,Hazard ratio ,Prostatic Neoplasms ,Androgen Antagonists ,Radiotherapy Dosage ,Middle Aged ,medicine.disease ,Neoadjuvant Therapy ,Surgery ,Radiation therapy ,Hormonal therapy ,Radiotherapy, Conformal ,business - Abstract
Summary Background In men with localised prostate cancer, conformal radiotherapy (CFRT) could deliver higher doses of radiation than does standard-dose conventional radical external-beam radiotherapy, and could improve long-term efficacy, potentially at the cost of increased toxicity. We aimed to present the first analyses of effectiveness from the MRC RT01 randomised controlled trial. Methods The MRC RT01 trial included 843 men with localised prostate cancer who were randomly assigned to standard-dose CFRT or escalated-dose CFRT, both administered with neoadjuvant androgen suppression. Primary endpoints were biochemical-progression-free survival (bPFS), freedom from local progression, metastases-free survival, overall survival, and late toxicity scores. The toxicity scores were measured with questionnaires for physicians and patients that included the Radiation Therapy Oncology Group (RTOG), the Late Effects on Normal Tissue: Subjective/Objective/Management (LENT/SOM) scales, and the University of California, Los Angeles Prostate Cancer Index (UCLA PCI) scales. Analysis was done by intention to treat. This trial is registered at the Current Controlled Trials website http://www.controlled-trials.com/ISRCTN47772397. Findings Between January, 1998, and December, 2002, 843 men were randomly assigned to escalated-dose CFRT (n=422) or standard-dose CFRT (n=421). In the escalated group, the hazard ratio (HR) for bPFS was 0·67 (95% CI 0·53–0·85, p=0·0007). We noted 71% bPFS (108 cumulative events) and 60% bPFS (149 cumulative events) by 5 years in the escalated and standard groups, respectively. HR for clinical progression-free survival was 0·69 (0·47–1·02; p=0·064); local control was 0·65 (0·36–1·18; p=0·16); freedom from salvage androgen suppression was 0·78 (0·57–1·07; p=0·12); and metastases-free survival was 0·74 (0·47–1·18; p=0·21). HR for late bowel toxicity in the escalated group was 1·47 (1·12–1·92) according to the RTOG (grade ≥2) scale; 1·44 (1·16–1·80) according to the LENT/SOM (grade ≥2) scales; and 1·28 (1·03–1·60) according to the UCLA PCI (score ≥30) scale. 33% of the escalated and 24% of the standard group reported late bowel toxicity within 5 years of starting treatment. HR for late bladder toxicity according to the RTOG (grade ≥2) scale was 1·36 (0·90–2·06), but this finding was not supported by the LENT/SOM (grade ≥2) scales (HR 1·07 [0·90–1·29]), nor the UCLA PCI (score ≥30) scale (HR 1·05 [0·81–1·36]). Interpretation Escalated-dose CFRT with neoadjuvant androgen suppression seems clinically worthwhile in terms of bPFS, progression-free survival, and decreased use of salvage androgen suppression. This additional efficacy is offset by an increased incidence of longer term adverse events.
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- 2007
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7. Escalated-dose versus control-dose conformal radiotherapy for prostate cancer: long-term results from the MRC RT01 randomised controlled trial
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David P, Dearnaley, Gordana, Jovic, Isabel, Syndikus, Vincent, Khoo, Richard A, Cowan, John D, Graham, Edwin G, Aird, David, Bottomley, Robert A, Huddart, Chakiath C, Jose, John H L, Matthews, Jeremy L, Millar, Claire, Murphy, J Martin, Russell, Christopher D, Scrase, Mahesh K B, Parmar, and Matthew R, Sydes
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Aged, 80 and over ,Male ,Time Factors ,Prostatic Neoplasms ,Androgen Antagonists ,Kaplan-Meier Estimate ,Middle Aged ,Prostate-Specific Antigen ,Disease-Free Survival ,Neoadjuvant Therapy ,Intention to Treat Analysis ,Treatment Outcome ,Chemotherapy, Adjuvant ,Risk Factors ,Disease Progression ,Humans ,Kallikreins ,Dose Fractionation, Radiation ,Radiotherapy, Conformal ,Aged ,Neoplasm Staging ,Proportional Hazards Models - Abstract
The aim of this trial was to compare dose-escalated conformal radiotherapy with control-dose conformal radiotherapy in patients with localised prostate cancer. Preliminary findings reported after 5 years of follow-up showed that escalated-dose conformal radiotherapy improved biochemical progression-free survival. Based on the sample size calculation, we planned to analyse overall survival when 190 deaths occurred; this target has now been reached, after a median 10 years of follow-up.RT01 was a phase 3, open-label, international, randomised controlled trial enrolling men with histologically confirmed T1b-T3a, N0, M0 prostate cancer with prostate specific antigen of less than 50 ng/mL. Patients were randomly assigned centrally in a 1:1 ratio, using a computer-based minimisation algorithm stratifying by risk of seminal vesicle invasion and centre to either the control group (64 Gy in 32 fractions, the standard dose at the time the trial was designed) or the escalated-dose group (74 Gy in 37 fractions). Neither patients nor investigators were masked to assignment. All patients received neoadjuvant androgen deprivation therapy for 3-6 months before the start of conformal radiotherapy, which continued until the end of conformal radiotherapy. The coprimary outcome measures were biochemical progression-free survival and overall survival. All analyses were done on an intention-to-treat basis. Treatment-related side-effects have been reported previously. This trial is registered, number ISRCTN47772397.Between Jan 7, 1998, and Dec 20, 2001, 862 men were registered and 843 subsequently randomly assigned: 422 to the escalated-dose group and 421 to the control group. As of Aug 2, 2011, 236 deaths had occurred: 118 in each group. Median follow-up was 10·0 years (IQR 9·1-10·8). Overall survival at 10 years was 71% (95% CI 66-75) in each group (hazard ratio [HR] 0·99, 95% CI 0·77-1·28; p=0·96). Biochemical progression or progressive disease occurred in 391 patients (221 [57%] in the control group and 170 [43%] in the escalated-dose group). At 10 years, biochemical progression-free survival was 43% (95% CI 38-48) in the control group and 55% (50-61) in the escalated-dose group (HR 0·69, 95% CI 0·56-0·84; p=0·0003).At a median follow-up of 10 years, escalated-dose conformal radiotherapy with neoadjuvant androgen deprivation therapy showed an advantage in biochemical progression-free survival, but this advantage did not translate into an improvement in overall survival. These efficacy data for escalated-dose treatment must be weighed against the increase in acute and late toxicities associated with the escalated dose and emphasise the importance of use of appropriate modern radiotherapy methods to reduce side-effects.UK Medical Research Council.
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- 2014
8. The outcome of a multi-centre feasibility study of online adaptive radiotherapy for muscle-invasive bladder cancer TROG 10.01 BOLART
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Colin Tang, Sandra Turner, Marketa Skala, Aldo Rolfo, Alex Tan, Dickon Hayne, Chakiath C Jose, Daniel Pham, Farshad Foroudi, Stephen Williams, Margot Lehman, George Hruby, Tomas Kron, Mathias Bressel, and Kumar Gogna
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Male ,medicine.medical_specialty ,medicine.medical_treatment ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Neoplasm Invasiveness ,Adaptive radiotherapy ,Multi centre ,Aged ,Bladder cancer ,business.industry ,Radiotherapy Planning, Computer-Assisted ,Muscle invasive ,Cancer ,Hematology ,Cone-Beam Computed Tomography ,Middle Aged ,medicine.disease ,Surgery ,Radiation therapy ,Clinical trial ,Oncology ,Urinary Bladder Neoplasms ,Feasibility Studies ,Urologic disease ,Female ,Radiology ,business ,Organ Sparing Treatments ,Radiotherapy, Image-Guided - Abstract
Purpose To assess whether online adaptive radiotherapy for bladder cancer is feasible across multiple Radiation Oncology departments using different imaging, delivery and recording technology. Materials and methods A multi-centre feasibility study of online adaptive radiotherapy, using a choice of three “plan of the day”, was conducted at 12 departments. Patients with muscle-invasive bladder cancer were included. Departments were activated if part of the pilot study or after a site-credentialing visit. There was real time review of the first two cases from each department. Results 54 patients were recruited, with 50 proceeding to radiotherapy. There were 43 males and 7 females with a mean age of 78 years. The tumour stages treated included T1 (1 patient), T2 (35), T3 (10) and T4 (4). One patient died of an unrelated cause during radiotherapy. The three adaptive plans were created before the 10th fraction in all cases. In 8 (16%) of the patients, a conventional plan using a ‘standard’ CTV to PTV margin of 1.5 cm was used for one or more fractions where the pre-treatment bladder CTV was larger than any of the three adaptive plans. The bladder CTV extended beyond the PTV on post treatment imaging in 9 (18%) of the 49 patients. Conclusions From a technical perspective an online adaptive radiotherapy technique can be instituted in a multi-centre setting. However, without further bladder filling control or imaging, a CTV to PTV margin of 7 mm is insufficient.
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- 2013
9. Protection Against Malaria by Intravenous Immunization with a Nonreplicating Sporozoite Vaccine
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Seder, R. A., Chang, L.-J., Enama, M. E., Zephir, K. L., Sarwar, U. N., Gordon, I. J., Holman, L. A., James, E. R., Billingsley, P. F., Gunasekera, A., Richman, A., Chakravarty, S., Manoj, A., Velmurugan, S., Li, M., Ruben, A. J., Li, T., Eappen, A. G., Stafford, R. E., Plummer, S. H., Hendel, C. S., Novik, L., Costner, P. J. M., Mendoza, F. H., Saunders, J. G., Nason, M. C., Richardson, J. H., Murphy, J., Davidson, S. A., Richie, T. L., Sedegah, M., Sutamihardja, A., Fahle, G. A., Lyke, K. E., Laurens, M. B., Roederer, M., Tewari, K., Epstein, J. E., Sim, B. K. L., Ledgerwood, J. E., Graham, B. S., Hoffman, S. L., DiGiovanni, C., Williams, P., Luongo, N., Mitchell, J., Florez, M. B., Larkin, B., Berkowitz, N., Wilson, B., Clarke, T., Vasilenko, O., Yamshchikov, G., Sitar, S., Stanford, L., Pittman, I., Bailer, R. T., Casazza, J., Decederfelt, H., Starling, J., Williams, E. C., Lau, A., Antonara, S., Brocious, J., Kemp, M., Inglese, J., Dranchak, P., Abot, E. N., Reyes, S., Ganeshan, H., Belmonte, M., Huang, J., Belmonte, A., Komisar, J., Abebe, Y., Getachew, Y., Patil, A., Matheny, S., Nelson, K., Overby, J., Pich, V., Wen, Y., Fan, R., Fomumbod, E., Awe, A., Chakiath, C., King, M., Orozco, M. S., Murshedkar, T., Padilla, D., Jiang, B., Gao, L., Kc, N., Xu, R., Adams, M., Plowe, C., Loblein, H., Renehan, P. Z., Kunchai, M., and Diep, L.
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parasitic diseases - Abstract
Malaria Sporozoite Vaccine Each year, hundreds of millions of people are infected with Plasmodium falciparum, the mosquito-borne parasite that causes malaria. A preventative vaccine is greatly needed. Seder et al. (p. 1359, published online 8 August; see the Perspective by Good) now report the results from a phase I clinical trial where subjects were immunized intravenously with a whole, attenuated sporozoite vaccine. Three of 9 subjects who received four doses and zero of 6 subjects who received five doses of the vaccine went on to develop malaria after controlled malaria infection. Both antibody titers and cellular immune responses correlated positively with the dose of vaccine received, suggesting that both arms of the adaptive immune response may have participated in the observed protection. Consistent, high-level, vaccine-induced protection against human malaria has only been achieved by inoculation of Plasmodium falciparum (Pf) sporozoites (SPZ) by mosquito bites. We report that the PfSPZ Vaccine—composed of attenuated, aseptic, purified, cryopreserved PfSPZ—was safe and wel-tolerated when administered four to six times intravenously (IV) to 40 adults. Zero of six subjects receiving five doses and three of nine subjects receiving four doses of 1.35 × 105 PfSPZ Vaccine and five of six nonvaccinated controls developed malaria after controlled human malaria infection (P = 0.015 in the five-dose group and P = 0.028 for overall, both versus controls). PfSPZ-specific antibody and T cell responses were dose-dependent. These data indicate that there is a dose-dependent immunological threshold for establishing high-level protection against malaria that can be achieved with IV administration of a vaccine that is safe and meets regulatory standards. Intravenous immunization with an attenuated whole malaria sporozoite vaccine protected volunteers in a phase I clinical trial. [Also see Perspective by Good] Intravenous immunization with an attenuated whole malaria sporozoite vaccine protected volunteers in a phase I clinical trial. [Also see Perspective by Good]
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- 2013
10. The early toxicity of escalated versus standard dose conformal radiotherapy with neo-adjuvant androgen suppression for patients with localised prostate cancer: results from the MRC RT01 trial (ISRCTN47772397)
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Ruth E Langley, Richard Stephens, David P. Dearnaley, Matthew R. Sydes, Robert Huddart, John Graham, Isabel Syndikus, John H L Matthews, Chakiath C Jose, John P Logue, and Christopher D Scrase
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Oncology ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Urinary Bladder ,Androgen suppression ,Gonadotropin-Releasing Hormone ,Prostate cancer ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,External beam radiotherapy ,Radiation Injuries ,Neoadjuvant therapy ,Aged ,business.industry ,Rectum ,Prostatic Neoplasms ,Androgen Antagonists ,Radiotherapy Dosage ,Hematology ,Middle Aged ,medicine.disease ,Acute toxicity ,Neoadjuvant Therapy ,Surgery ,Radiation therapy ,Toxicity ,Hormonal therapy ,Radiotherapy, Conformal ,business - Abstract
Five-year disease-free survival rates for localised prostate cancer following standard doses of conventional radical external beam radiotherapy are around 80%. Conformal radiotherapy (CFRT) raises the possibility that radiotherapy doses can be increased and long-term efficacy outcomes improved, with safety an important consideration.MRC RT01 is a randomised controlled trial of 862 men with localised prostate cancer comparing Standard CFRT (64Gy/32f) versus Escalated CFRT (74Gy/37f), both administered with neo-adjuvant androgen suppression. Early toxicity was measured using physician-reported instruments (RTOG, LENT/SOM, Royal Marsden Scales) and patient-reported questionnaires (MOS SF-36, UCLA Prostate Cancer Index, FACT-P).Overall early radiotherapy toxicity was similar, apart from increased bladder, bowel and sexual toxicity, in the Escalated Group during a short immediate post-radiotherapy period. Toxicity in both groups had abated by week 12. Using RTOG Acute Toxicity scores, cumulative Grade 2 bladder and bowel toxicity was 38% and 30% for Standard Group and 39% and 33% in Escalated Group, respectively. Urinary frequency (Royal Marsden Scale) improved in both groups from pre-androgen suppression to 6 months post-radiotherapy (p0.001), but bowel and sexual functioning deteriorated. This pattern was supported by patient-completed assessments. Six months after starting radiotherapy the incidence of RTOG Gradeor = 2 side-effects was low (1%); but there were six reports of rectal ulceration (6 Escalated Group), six haematuria (5 Escalated Group) and eight urethral stricture (6 Escalated Group).The two CFRT schedules with neo-adjuvant androgen suppression have broadly similar early toxicity profiles except for the immediate post-RT period. At 6 months and compared to before hormone therapy, bladder symptoms improved, whereas bowel and sexual symptoms worsened. These assessments of early treatment safety will be complemented by further follow-up to document late side-effects and efficacy.
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- 2006
11. Estimation of radiation-induced interphase cell death in cultures of human tumor material and in cell lines
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Chakiath C Jose, Julian B. White, John R. Whittaker, Richard Coutts, Elaine S. Marshall, Richard J. Isaacs, Michael L. Rice, Randall P. Morton, Christopher E. Furneaux, James H. F. Shaw, John H L Matthews, James A. Kirker, and Bruce C. Baguley
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Cancer Research ,Pathology ,medicine.medical_specialty ,Cell cycle checkpoint ,Cell Death ,Paclitaxel ,Melanoma ,medicine.medical_treatment ,Cancer ,General Medicine ,Biology ,Cell cycle ,medicine.disease ,Mitotic inhibitor ,Radiation therapy ,Oncology ,Apoptosis ,Neoplasms ,medicine ,Cancer research ,Tumor Cells, Cultured ,Humans ,Radiosensitivity ,Interphase - Abstract
A short-term assay method able to estimate the radiation response of human cancer tissue samples would be of great advantage to the individualization of radiotherapy in cancer patients. However, the effect of radiation on [ 3 H]thymidine incorporation by proliferating cells reflects a composite of cell cycle arrest and induced cell death pathways. Here we consider whether it is feasible to correct for cell cycle effects based on comparison of the effects of radiation and the mitotic inhibitor paclitaxel on [ 3 H]thymidine incorporation. Sixty-two short-term (7-day) cultures of human tumor tissue from 61 patients with melanoma, gynecological cancer, brain cancer, and head and neck cancer, as well as 18 5-day cultures of low passage human tumor cell lines, were irradiated at doses from 2 to 9 Gy, or exposed to paclitaxel (200 nM). [ 3 H]Thymidine incorporation was measured at the end of the incubation. Cell cycle times could be estimated from the paclitaxel data and were 2.7 to 18.6 days for melanomas, 2.5 to >40 days for carcinomas, 3.9 to 39 days for brain tumors, and 1.1 to 3.8 days for cell lines. The effects of radiation on ['H]thymidine incorporation varied widely (0-97% and 0-99% inhibition for 2 and 9 Gy, respectively), and in 23 of the clinical samples, but in none of the cell lines, radiation caused significantly greater inhibition of 3 H]thymidine incorporation than paclitaxel (p < 0.05). We argue that that these differences reflect radiation-induced cell loss from G 1 phase and/or S phase. Responses of short-term cultures of clinical tumor material to radiation, with appropriate correction for cell cycle effects, might have the potential to provide information on radiation-induced cell death in individual patients.
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- 2004
12. What is optimal timing of post prostatectomy radiotherapy? Is adjuvant radiotherapy equivalent to early salvage radiotherapy? The 'RAVES' phase III randomized clinical trial
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Sandra Turner, Annette Haworth, Ian D. Davis, Richard Fisher, Gillian M. Duchesne, Andrew Kneebone, John H L Matthews, David Joseph, K. Wiltshire, Colin Tang, Jeremy Millar, Henry H. Woo, Chakiath C Jose, Carol Fraser-Browne, Scott Williams, Maria Pearse, Tee Lim, Mark Frydenberg, Mark Sidhom, and Nigel Spry
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Cancer Research ,medicine.medical_specialty ,Adjuvant radiotherapy ,Post prostatectomy radiotherapy ,business.industry ,medicine.medical_treatment ,Surgery ,law.invention ,Oncology ,Randomized controlled trial ,law ,Salvage radiotherapy ,medicine ,Positive Margins ,In patient ,business ,Adjuvant - Abstract
TPS4690 Background: Three randomised trials have demonstrated a significant benefit of adjuvant post prostatectomy radiotherapy in patients with positive margins, extra capsular extension or seminal vesicle involvement, and it should be regarded as current standard of care. However, adopting this approach will expose nearly half of such patients to unnecessary radiotherapy and potential treatment morbidity. Salvage radiotherapy, if given early, is recognised to be effective. The RAVES trial is designed to compare these two approaches, and was developed in collaboration with the Trans Tasman Radiation Oncology Group (TROG), Australian and New Zealand Urogenital and Prostate Trials Group (ANZUP) and the Urological Society of Australia and New Zealand (USANZ). It aims to test the hypothesis that active surveillance with early salvage radiotherapy is non-inferior to adjuvant radiotherapy with respect to risk of biochemical failure (defined as PSA level ≥ 0.40 ng/mL and rising). Methods: Patients must have at least one of the following risk factors: positive margins, extracapsular extension or seminal vesicle involvement. They must start radiotherapy within 4 months of radical prostatectomy (RP) and have an undetectable PSA (≤ 0.10 ng/ml) prior to randomisation. Patients receiving androgen deprivation or who have an artificial hip are excluded. Eligible patients are randomised to either: Arm 1: Adjuvant RT (64Gy in 32#) commenced within 4 months of RP, or Arm 2: Active surveillance with 3 monthly PSA tests and commencement of early salvage RT (64Gy in 32#) if PSA rises ≥ 0.20 ng/ml. Stratification is by seminal vesicle invasion, Gleason Score, pre-operative PSA, margin positivity (no/yes) and radiotherapy institution. A sample size of 470 patients is required to detect a 10% non-inferiority margin in the 5-year biochemical failure-free rate between the adjuvant and active surveillance arms. As of 31 Jan 2012, 186 patients have been recruited across 26 centres in Australia and New Zealand. A meta analysis with the MRC RADICALS and GETUG-17 trials will be prospectively designed to detect a survival difference between the two approaches.
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- 2012
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13. Estimation of Radiation-Induced Interphase Cell Death in Cultures of Human Tumor Material and in Cell Lines
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Marshall, Elaine S., primary, Baguley, Bruce C., additional, Matthews, John H. L., additional, Jose, Chakiath C., additional, Furneaux, Christopher E., additional, Shaw, James H. F., additional, Kirker, James A., additional, Morton, Randall P., additional, White, Julian B., additional, Rice, Michael L., additional, Isaacs, Richard J., additional, Coutts, Richard, additional, and Whittaker, John R., additional
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- 2003
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14. Cyclopentadiene as a Multifunctional Reagent for Normal- and Inverse-Electron Demand Diels-Alder Bioconjugation.
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Ting CY, Kolbeck PT, Colombo R, Chakiath C, Rice M, Marelli M, and Christie RJ
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- Amino Acids chemistry, Cycloaddition Reaction, Cyclopentanes, Electrons, Indicators and Reagents, Heterocyclic Compounds, Immunoconjugates
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Optimizing the Diels-Alder (DA) reaction for aqueous coupling has resulted in practical methods to link molecules such as drugs and diagnostic agents to proteins. Both normal electron demand (NED) and inverse electron demand (IED) DA coupling schemes have been employed, but neither mechanism entails a common multipurpose reactive group. This report focuses on expanding the bioconjugation toolbox for cyclopentadiene through the identification of reactive groups that couple through NED or IED mechanisms in aqueous solution. Dienophiles and tetrazine derivatives were screened for reactivity and selectivity toward antibodies bearing cyclopentadiene amino acids to yield bioconjugates. Twelve NED dienophiles and four tetrazine-based IED substrates were identified as capable of practical biocoupling. Furthermore, tetrazine ligation to cyclopentadiene occurred at a rate of 3.3 ± 0.5 M
-1 s-1 and was capable of bioorthogonal transformations, as evidenced by the selective protein labeling in serum. Finally, an antibody-drug conjugate (ADC)-bearing monomethyl auristatin E was prepared via tetrazine conjugation to cyclopentadiene. The resulting ADC was stable and demonstrated potent activity in vitro . These findings expand the utility of cyclopentadiene as a tool to couple entities to proteins via dual DA addition mechanisms.- Published
- 2022
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15. A Reactive Antibody Platform for One-Step Production of Antibody-Drug Conjugates through a Diels-Alder Reaction with Maleimide.
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St Amant AH, Huang F, Lin J, Lemen D, Chakiath C, Mao S, Fazenbaker C, Zhong H, Harper J, Xu W, Patel N, Adams L, Vijayakrishnan B, Howard PW, Marelli M, Wu H, Gao C, Read de Alaniz J, and Christie RJ
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- Animals, CHO Cells, Cell Survival drug effects, Cricetulus, Cycloaddition Reaction, Humans, Immunoconjugates pharmacology, Models, Molecular, PC-3 Cells, Protein Conformation, Spiro Compounds chemistry, Immunoconjugates chemistry, Maleimides chemistry
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The normal electron-demand Diels-Alder (DA) cycloaddition is a classic transformation routinely used in synthesis; however, applications in biological systems are limited. Here, we report a spiro[2.4]hepta-4,6-diene-containing noncanonical amino acid (SCpHK) capable of efficient incorporation into antibodies and subsequent coupling with maleimide via a DA reaction. SCpHK was stable throughout protein expression in mammalian cells and enabled covalent attachment of maleimide drug-linkers yielding DA antibody-drug conjugates (DA-ADCs) with nearly quantitative conversion in a one-step process. The uncatalyzed DA reaction between SCpHK and maleimide in aqueous buffer was rapid (1.8-5.4 M
-1 s-1 ), and the antibody-drug adduct was stable in rat serum for at least 1 week at 37 °C. Anti-EphA2 DA-ADCs containing AZ1508 or SG3249 maleimide drug-linkers were potent inhibitors of tumor growth in PC3 tumor models in vivo. The DA bioconjugation strategy described here represents a simple method to produce site-specific and stable ADCs with maleimide drug-linkers.- Published
- 2019
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16. Two-years Postradiotherapy Biopsies: Lessons from MRC RT01 Trial.
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Kass-Iliyya A, Jovic G, Murphy C, Fisher C, Syndikus I, Jose C, Scrase CD, Graham JD, Nicol D, Sydes MR, and Dearnaley D
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- Aged, Androgen Antagonists therapeutic use, Biopsy, Follow-Up Studies, Humans, Male, Middle Aged, Neoadjuvant Therapy, Progression-Free Survival, Prostatic Neoplasms blood, Prostatic Neoplasms therapy, Radiotherapy Dosage, Randomized Controlled Trials as Topic, Survival Rate, Prostate pathology, Prostate-Specific Antigen blood, Prostatic Neoplasms pathology, Prostatic Neoplasms radiotherapy
- Abstract
Background: The importance of 2-yr postradiotherapy prostate biopsy status remains uncertain., Objective: To assess the value of 2 year post treatment biopsies in a randomised trial of radiotherapy dose escalation., Design, Setting, and Participants: Between 1998 and 2001, 843 men with localised prostate cancer were randomised to receive either control-64Gy or escalated-74Gy conformal radiotherapy (CFRT) in the MRC RT01 trial in combination with 3-6-mo neoadjuvant androgen deprivation therapy. Prostate biopsies were planned at 2 yr from start of CFRT in suitable men., Outcome Measurements and Statistical Analysis: Prostate biopsy results and prostate-specific antigen (PSA) levels performed at 2 yr post-CFRT were evaluated with long-term biochemical progression free survival (bPFS) and overall survival. Outcome measures were timed from the 2-yr biopsy using a landmark approach., Results and Limitations: A 2-yr biopsy was performed in 312/843 patients. One hundred and seventy-seven patients were included in the per-protocol group with median follow-up of 7.8 yr from biopsy. Median PSA at biopsy was 0.5ng/ml. Sixty-four bPFS events were reported: 46/145 (32%) in patients with negative, 6/18 (33%) suspicious, and 12/14 (86%) positive biopsies. A positive biopsy was prognostic of worse bPFS, going forward, compared with negative and suspicious biopsies, hazard ratio (HR)=4.81 (95% confidence interval [CI]: 2.50-9.26, p<0.001). The estimate for survival was HR=1.58 (95% CI: 0.52-4.78, p=0.42). PSA values at 2 yr between 1.01ng/ml and 2.09ng/ml were also associated with subsequent PSA failures (HR=2.71, 95% CI: 1.98-3.71), bPFS events (HR=2.45, 95% CI: 1.81-3.32), and prostate cancer-specific survival (HR=2.87, 95% CI: 1.08-7.64) compared with PSA ≤1.0ng/ml., Conclusions: Two-year postradiotherapy prostate biopsies have limited value in patients with PSA control but both positive biopsy and higher PSA status are strongly associated with future bPFS events. A policy of selected biopsy may provide an opportunity for early salvage interventions., Patient Summary: Routine 2-yr postradiotherapy biopsy is not recommended but can be considered in selected patients with unfavourable post-treatment prostate-specific antigen levels who are suitable for early salvage treatments., (Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.)
- Published
- 2018
- Full Text
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17. A Phase III trial to investigate the timing of radiotherapy for prostate cancer with high-risk features: background and rationale of the Radiotherapy -- Adjuvant Versus Early Salvage (RAVES) trial.
- Author
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Pearse M, Fraser-Browne C, Davis ID, Duchesne GM, Fisher R, Frydenberg M, Haworth A, Jose C, Joseph DJ, Lim TS, Matthews J, Millar J, Sidhom M, Spry NA, Tang CI, Turner S, Williams SG, Wiltshire K, Woo HH, and Kneebone A
- Subjects
- Adenocarcinoma drug therapy, Adenocarcinoma pathology, Adenocarcinoma surgery, Australia, Disease-Free Survival, Humans, Male, Neoplasm Invasiveness, New Zealand, Prostate-Specific Antigen, Prostatic Neoplasms drug therapy, Prostatic Neoplasms pathology, Prostatic Neoplasms surgery, Risk Assessment, Time Factors, Treatment Outcome, Adenocarcinoma radiotherapy, Androgen Antagonists therapeutic use, Antineoplastic Agents, Hormonal therapeutic use, Prostatectomy, Prostatic Neoplasms radiotherapy, Radiotherapy, Adjuvant, Salvage Therapy methods
- Abstract
Objectives: To test the hypothesis that observation with early salvage radiotherapy (SRT) is not inferior to 'standard' treatment with adjuvant RT (ART) with respect to biochemical failure in patients with pT3 disease and/or positive surgical margins (SMs) after radical prostatectomy (RP). To compare the following secondary endpoints between the two arms: patient-reported outcomes, adverse events, biochemical failure-free survival, overall survival, disease-specific survival, time to distant failure, time to local failure, cost utility analysis, quality adjusted life years and time to androgen deprivation., Patients and Methods: The Radiotherapy - Adjuvant Versus Early Salvage (RAVES) trial is a phase III multicentre randomised controlled trial led by the Trans Tasman Radiation Oncology Group (TROG), in collaboration with the Urological Society of Australia and New Zealand (USANZ), and the Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP). In all, 470 patients are planned to be randomised 1:1 to either ART commenced at ≤4 months of RP (standard of care) or close observation with early SRT triggered by a PSA level of >0.20 ng/mL (experimental arm). Eligible patients have had a RP for adenocarcinoma of the prostate with at least one of the following risk factors: positive SMs ± extraprostatic extension ± seminal vesicle involvement. The postoperative PSA level must be ≤0.10 ng/mL. Rigorous investigator credentialing and a quality assurance programme are designed to promote consistent RT delivery among patients., Results: Trial is currently underway, with 258 patients randomised as of 31 October 2013. International collaborations have developed, including a planned meta-analysis to be undertaken with the UK Medical Research Council/National Cancer Institute of Canada Clinical Trials Group RADICALS (Radiotherapy and Androgen Deprivation In Combination with Local Surgery) trial and an innovative psycho-oncology sub-study to investigate a patient decision aid resource., Conclusion: On the current evidence available, it remains unclear if ART is equivalent or superior to observation with early SRT., (© 2014 The Authors. BJU International © 2014 BJU International.)
- Published
- 2014
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18. Establishment of an in vitro assay for assessing the effects of drugs on the liver stages of Plasmodium vivax malaria.
- Author
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Chattopadhyay R, Velmurugan S, Chakiath C, Andrews Donkor L, Milhous W, Barnwell JW, Collins WE, and Hoffman SL
- Subjects
- Animals, Anopheles parasitology, Antimalarials pharmacology, Carcinoma, Hepatocellular drug therapy, Carcinoma, Hepatocellular parasitology, Cryopreservation, Disease Models, Animal, Hepatocytes drug effects, Hepatocytes parasitology, Humans, In Vitro Techniques, Microscopy, Fluorescence methods, Pan troglodytes, Plasmodium vivax metabolism, Primaquine pharmacology, Salivary Glands metabolism, Sporozoites chemistry, Liver drug effects, Liver metabolism, Malaria, Vivax metabolism
- Abstract
Plasmodium vivax (Pv) is the second most important human malaria parasite. Recent data indicate that the impact of Pv malaria on the health and economies of the developing world has been dramatically underestimated. Pv has a unique feature in its life cycle. Uninucleate sporozoites (spz), after invasion of human hepatocytes, either proceed to develop into tens of thousands of merozoites within the infected hepatocytes or remain as dormant forms called hypnozoites, which cause relapses of malaria months to several years after the primary infection. Elimination of malaria caused by Pv will be facilitated by developing a safe, highly effective drug that eliminates Pv liver stages, including hypnozoites. Identification and development of such a drug would be facilitated by the development of a medium to high throughput assay for screening drugs against Pv liver stages. We undertook the present pilot study to (1) assess the feasibility of producing large quantities of purified, vialed, cryopreserved Pv sporozoites and (2) establish a system for culturing the liver stages of Pv in order to assess the effects of drugs on the liver stages of Pv. We used primaquine (PQ) to establish this assay model, because PQ is the only licensed drug known to clear all Pv hepatocyte stages, including hypnozoites, and the effect of PQ on Pv hepatocyte stage development in vitro has not previously been reported. We report that we have established the capacity to reproducibly infect hepatoma cells with purified, cyropreserved Pv spz from the same lot, quantitate the primary outcome variable of infected hepatoma cells and demonstrate the inhibitory activity of primaquine on the infected hepatoma cells. We have also identified small parasite forms that may be hypnozoites. These data provide the foundation for finalizing a medium throughput, high content assay to identify new drugs for the elimination of all Pv liver stages.
- Published
- 2010
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19. Thermal Stabilization of Erwinia chrysanthemi pectin methylesterase a for application in a sugar beet pulp biorefinery.
- Author
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Chakiath C, Lyons MJ, Kozak RE, and Laufer CS
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- Amino Acid Substitution genetics, Bacterial Proteins genetics, Biomass, Carboxylic Ester Hydrolases genetics, Directed Molecular Evolution methods, Enzyme Stability, Protein Stability, Bacterial Proteins chemistry, Bacterial Proteins metabolism, Beta vulgaris metabolism, Carboxylic Ester Hydrolases chemistry, Carboxylic Ester Hydrolases metabolism, Dickeya chrysanthemi enzymology
- Abstract
Directed evolution approaches were used to construct a thermally stabilized variant of Erwinia chrysanthemi pectin methylesterase A. The final evolved enzyme has four amino acid substitutions that together confer a T(m) value that is approximately 11 degrees C greater than that of the wild-type enzyme, while maintaining near-wild-type kinetic properties. The specific activity, with saturating substrate, of the thermally stabilized enzyme is greater than that of the wild-type enzyme when both are operating at their respective optimal temperatures, 60 degrees C and 50 degrees C. The engineered enzyme may be useful for saccharification of biomass, such as sugar beet pulp, with relatively high pectin content. In particular, the engineered enzyme is able to function in biomass up to temperatures of 65 degrees C without significant loss of activity. Specifically, the thermally stabilized enzyme facilitates the saccharification of sugar beet pulp by the commercial pectinase preparation Pectinex Ultra SPL. Added pectin methylesterase increases the initial rate of sugar production by approximately 50%.
- Published
- 2009
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20. Estimation of radiation-induced interphase cell death in cultures of human tumor material and in cell lines.
- Author
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Marshall ES, Baguley BC, Matthews JH, Jose CC, Furneaux CE, Shaw JH, Kirker JA, Morton RP, White JB, Rice ML, Isaacs RJ, Coutts R, and Whittaker JR
- Subjects
- Cell Death drug effects, Cell Death radiation effects, Humans, Interphase drug effects, Paclitaxel pharmacology, Tumor Cells, Cultured, Interphase radiation effects, Neoplasms pathology
- Abstract
A short-term assay method able to estimate the radiation response of human cancer tissue samples would be of great advantage to the individualization of radiotherapy in cancer patients. However, the effect of radiation on [3H]thymidine incorporation by proliferating cells reflects a composite of cell cycle arrest and induced cell death pathways. Here we consider whether it is feasible to correct for cell cycle effects based on comparison of the effects of radiation and the mitotic inhibitor paclitaxel on [3H]thymidine incorporation. Sixty-two short-term (7-day) cultures of human tumor tissue from 61 patients with melanoma, gynecological cancer, brain cancer, and head and neck cancer, as well as 18 5-day cultures of low passage human tumor cell lines, were irradiated at doses from 2 to 9 Gy, or exposed to paclitaxel (200 nM). [3H]Thymidine incorporation was measured at the end of the incubation. Cell cycle times could be estimated from the paclitaxel data and were 2.7 to 18.6 days for melanomas, 2.5 to >40 days for carcinomas, 3.9 to 39 days for brain tumors, and 1.1 to 3.8 days for cell lines. The effects of radiation on [3H]thymidine incorporation varied widely (0-97% and 0-99% inhibition for 2 and 9 Gy, respectively), and in 23 of the clinical samples, but in none of the cell lines, radiation caused significantly greater inhibition of [3H]thymidine incorporation than paclitaxel (p < 0.05). We argue that that these differences reflect radiation-induced cell loss from G1 phase and/or S phase. Responses of short-term cultures of clinical tumor material to radiation, with appropriate correction for cell cycle effects, might have the potential to provide information on radiation-induced cell death in individual patients.
- Published
- 2004
- Full Text
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