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Curtis JR, Kramer JM, Martin C, Saag KG, Patkar N, Shatin D, Burgess M, Xie A, Braun MM. Heart failure among younger rheumatoid arthritis and Crohn's patients exposed to TNF-alpha antagonists. Rheumatology (Oxford) 2007; 46:1688-93. [PMID: 17938138 DOI: 10.1093/rheumatology/kem212] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES New onset heart failure (HF) has been associated with the use of TNF-alpha antagonists etanercept and infliximab based upon spontaneous adverse event reports. HF clinical trials of these agents were stopped early due to futility or worsening of existing HF. A potential association between etanercept and infliximab and new onset HF has been studied minimally at a population level. METHODS Using administrative claims from a large U.S. health care organization, we identified rheumatoid arthritis (RA) and Crohn's disease (CD) patients receiving infliximab or etanercept (exposed), and comparator cohorts of RA and CD patients receiving non-biologic immunosuppressives (unexposed). We studied adults < 50 years to reduce potential confounding related to common age-related comorbidities. Based on abstracted medical records of suspected HF cases, a physician panel adjudicated cases as definite, possible or no HF. RESULTS Among 4018 RA and CD patients with mean duration follow-up of 18 months, 9 of 33 suspected HF cases (identified using claims data) were adjudicated as definite (n = 5) or possible (n = 4) HF. The relative risk of HF among TNF-alpha antagonist-treated RA and CD patients was 4.3 and 1.2, respectively (P = NS for both). The absolute difference in cumulative incidence of HF among infliximab or etanercept-exposed compared to unexposed patients was 3.4 and 0.3 cases per 1000 persons for RA and CD (P = NS), respectively, yielding a number needed to harm of 294 for RA and 3333 for CD. CONCLUSION We found only a small number of presumed HF cases (n = 9, or 0.2%) in a large population of relatively young RA and CD patients. Although there was an increased relative risk of incident, HF that was not statistically significant among those exposed to TNF-alpha antagonists compared to those unexposed, larger cohorts are needed to provide more precise risk estimates and permit adjustment for potential confounding.
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Burgess M. The necessity of physician involvement in the political process. Interview by Shawn Friesen. BULLETIN OF THE AMERICAN COLLEGE OF SURGEONS 2007; 92:59-64. [PMID: 17691618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
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Moir S, Shaw L, Haluska B, Jenkins C, Rakhit D, Burgess M, Marwick T. Left Ventricular Opacification for the Diagnosis of Coronary Artery Disease with Stress Echocardiography: An Angiographic Study of Incremental Benefit and Cost-Effectiveness. Heart Lung Circ 2007. [DOI: 10.1016/j.hlc.2007.06.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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79
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Moir S, Hanekom L, Fang ZY, Haluska B, Wong C, Burgess M, Marwick TH. Relationship between myocardial perfusion and dysfunction in diabetic cardiomyopathy: a study of quantitative contrast echocardiography and strain rate imaging. Heart 2006; 92:1414-9. [PMID: 16606865 PMCID: PMC1861031 DOI: 10.1136/hrt.2005.079350] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVE To use quantitative myocardial contrast echocardiography (MCE) and strain rate imaging (SRI) to assess the role of microvascular disease in subclinical diabetic cardiomyopathy. METHODS Stress MCE and SRI were performed in 48 patients (22 with type II diabetes mellitus (DM) and 26 controls), all with normal left ventricular systolic function and no obstructive coronary disease by quantitative coronary angiography. Real-time MCE was acquired in three apical views at rest and after combined dipyridamole-exercise stress. Myocardial blood flow (MBF) was quantified in the 10 mid- and apical cardiac segments at rest and after stress. Resting peak systolic strain rate (SR) and peak systolic strain (epsilon) were calculated in the same 10 myocardial segments. RESULTS The DM and control groups were matched for age, sex and other risk factors, including hypertension. The DM group had higher body mass index and left ventricular mass index. Quantitative SRI analysis was possible in all patients and quantitative MCE in 46 (96%). The mean epsilon, SR and MBF reserve were all significantly lower in the DM group than in controls, with diabetes the only independent predictor of each parameter. No correlation was seen between MBF and SR (r = -0.01, p = 0.54) or between MBF and epsilon (r = -0.20, p = 0.20). CONCLUSIONS Quantitative MCE shows that patients with diabetes but no evidence of obstructive coronary artery disease have impaired MBF reserve, but abnormal transmural flow and subclinical longitudinal myocardial dysfunction are not related.
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Longstaff H, Burgess M, Lewis P. Comparing methods of ethical consultation for biotechnology related issues. HEALTH LAW REVIEW 2006; 15:37-8. [PMID: 17153274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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81
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Vorburger SA, Xing Y, Hunt KK, Lakin GE, Benjamin RS, Feig BW, Pisters PWT, Ballo MT, Chen L, Trent J, Burgess M, Patel S, Pollock RE, Cormier JN. Angiosarcoma of the breast. Cancer 2005; 104:2682-8. [PMID: 16288486 DOI: 10.1002/cncr.21531] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Angiosarcoma of the breast is a rare entity. The objectives of this study were to evaluate prognostic factors and determine outcomes in a large contemporary series of patients. METHODS Clinical and pathologic factors were analyzed in all patients with angiosarcoma of the breast treated between 1990 and 2003. Overall survival (OS) and disease-free survival (DFS) were estimated using the methods of Kaplan and Meier. Multivariate analyses were performed to evaluate prognostic factors. RESULTS Fifty-five women with angiosarcoma of the breast were identified. The median age was 49.1 years, and the median follow-up time was 3.7 years. The median OS and DFS were 2.96 years and 2.26 years, respectively. For the 32 patients with primary angiosarcoma of the breast 5-year OS was 59%. Twenty-three (42%) patients had received prior radiation therapy for the treatment of breast cancer. These patients with radiation therapy-associated angiosarcoma were on average 30 years older and less likely to present with distant metastatic disease than patients presenting with radiation-naive angiosarcoma of the breast. Although radiation-naive patients appeared to have had better early DFS and OS, the Kaplan-Meier curves were not statistically different between patients with radiation therapy-associated disease and radiation therapy-naive patients. On multivariate analysis, tumor recurrence (P = 0.006) was the only significant adverse prognostic factor noted for OS. CONCLUSIONS In this series of 55 patients with angiosarcoma of the breast, radiation therapy-naive angiosarcomas occurred in younger patients, but they behaved similarly to radiation therapy-associated angiosarcomas.
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Brunger F, Burgess M. A cultural understanding of research ethics governance. HEALTH LAW REVIEW 2005; 13:69-74. [PMID: 16459417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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83
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Sandler A, Gordon M, De Alwis DP, Pouliquen I, Green L, Marder P, Chaudhary A, Fife K, Battiato L, Sweeney C, Jordan C, Burgess M, Slapak CA. A Phase I trial of a potent P-glycoprotein inhibitor, zosuquidar trihydrochloride (LY335979), administered intravenously in combination with doxorubicin in patients with advanced malignancy. Clin Cancer Res 2004; 10:3265-72. [PMID: 15161679 DOI: 10.1158/1078-0432.ccr-03-0644] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Our intention was to (a) to investigate the safety and tolerability of a potent P-glycoprotein modulator, zosuquidar trihydrochloride (LY335979), when administered i.v. alone or in combination with doxorubicin, (b) to determine the pharmacokinetics of zosuquidar and correlate exposure to inhibition of P-glycoprotein function in a surrogate assay, and (c) to compare the pharmacokinetics of doxorubicin in the presence and absence of zosuquidar. PATIENTS AND METHODS Patients with advanced malignancies who provided written informed consent received zosuquidar and doxorubicin administered separately during the first cycle of therapy and then concurrently in subsequent cycles. Zosuquidar was given i.v. over 48 h in a cohort-dose escalation manner until the occurrence of dose-limiting toxicity or protocol specified maximum exposure. Doxorubicin doses of 45, 60, 75 mg/m(2) were administered during the course of the trial. RESULTS Dose escalation proceeded through 9 cohorts with a total of 40 patients. The maximal doses administered were 640 mg/m(2) of zosuquidar and 75 mg/m(2) of doxorubicin. No dose-limiting toxicity of zosuquidar was observed. Pharmacokinetic analysis revealed that, in the presence of zosuquidar at doses that exceeded 500 mg, there was a modest decrease in clearance (17-22%) and modest increase in area under the curve (15-25%) of doxorubicin. This change was associated with an enhanced leukopenia and thrombocytopenia but was without demonstrable clinical significance. The higher doses of zosuquidar were associated with maximal P-glycoprotein inhibition in natural killer cells. CONCLUSION Zosuquidar can be safely coadministered with doxorubicin using a 48 h i.v. dosing schedule.
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Gerrard G, Payne E, Baker RJ, Jones DT, Potter M, Prentice HG, Ethell M, McCullough H, Burgess M, Mehta AB, Ganeshaguru K. Clinical effects and P-glycoprotein inhibition in patients with acute myeloid leukemia treated with zosuquidar trihydrochloride, daunorubicin and cytarabine. Haematologica 2004; 89:782-90. [PMID: 15257929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
BACKGROUND AND OBJECTIVES P-glycoprotein (P-gp) is a major cause of multidrug resistance (MDR) in acute myelogenous leukemia (AML) and is thought to contribute to the failure of chemotherapy. Zosuquidar trihydochloride (Z.3HCL) is a potent and selective inhibitor of P-gp which rapidly and effectively inhibits drug efflux. DESIGN AND METHODS The aim of this study was to evaluate the clinical effects of Z.3HCL and determine its influence on P-gp activity. Sixteen AML patients were entered into a phase 1 dose ranging clinical trial of Z.3HCL, co-administered intravenously with daunorubicin and cytosine arabinoside (ARA-C). Clinical outcomes, toxicity abd adverse events were assessed. P-gp function was analyzed by flow cytometry. In vitro cytotoxicity was studied using the MTT assay. RESULTS Eleven patients achieved a complete remission and one a partial remission with a median survival of 559 (range 38-906) days. Non-hematologic grade 3 and 4 toxicities were seen in 4 patients. Z.3HCL infusion was associated with rapid inhibition of Rh123 efflux in CD56+ cells in 16/16 patients and in CD33+ cells from 6/10 patients. The median inhibition was 95% for CD56+ cells and 85.25% for CD33+ cells was significantly elevated in 6/16 patients. The median IC50, using a MTT assay for daunorubicin, decreased significantly between Z.3HCL modulated and unmodulated cells (n=11,153 and 247 ng/mL respectively, p=0.01). INTERPRETATION AND CONCLUSIONS The modulator Z.3HCL is a specific inhibitor of P-gp efflux and can be given safely to patients with AML in combination with induction doses of conventional cytotoxic drugs.
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Callies S, de Alwis DP, Mehta A, Burgess M, Aarons L. Population pharmacokinetic model for daunorubicin and daunorubicinol coadministered with zosuquidar.3HCl (LY335979). Cancer Chemother Pharmacol 2004; 54:39-48. [PMID: 15045528 DOI: 10.1007/s00280-004-0775-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2003] [Accepted: 01/21/2004] [Indexed: 11/27/2022]
Abstract
PURPOSE The impact of zosuquidar.3HCl, an inhibitor of P-glycoprotein, on the pharmacokinetics of daunorubicin and daunorubicinol was examined in a phase I trial using a population approach. Pharmacokinetic and pharmacodynamic properties of zosuquidar.3HCl were also determined. METHODS The pharmacokinetics of daunorubicin and daunorubicinol were studied following daunorubicin administration on day 1 (50 mg/m2 i.v. infusion over 10 min) alone and on day 3 concomitantly with zosuquidar.3HCl (i.v. 200 or 300 mg/m2 over 6 h or 400 mg over 3 h). Of a total of 18 patients entered, 16 with acute leukemia completed the study. RESULTS A three-compartment pharmacokinetic model adequately described daunorubicin concentration-time profiles. Five- and four-compartment models adequately described the daunorubicin-daunorubicinol pharmacokinetics in the absence and presence of zosuquidar.3HCl, respectively. The impact of zosuquidar.3HCl on coadministered daunorubicin was minimal, with a 10% reduction in daunorubicin clearance. The model predicted a 50% decrease in daunorubicinol apparent clearance in the presence of zosuquidar.3HCl. A direct concentration-effect relationship between zosuquidar.3HCl concentrations and inhibition of rhodamine 123 (Rh123) efflux in CD56 lymphocytes was defined by a sigmoid E(max) model. The IC(50) was 31.7 microg/l. The zosuquidar.3HCl dosing regimen led to concentrations in excess of the IC(90) (169.6 microg/l) and provided maximal P-glycoprotein inhibition during the distribution phases of daunorubicin. CONCLUSIONS The decrease in daunorubicin and daunorubicinol clearance in the presence of zosuquidar.3HCl likely reflects inhibition of P-glycoprotein in the bile canaliculi impeding their biliary excretion. The results need to be interpreted carefully due to the sequential nature of daunorubicin administration and analysis.
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Callies S, de Alwis DP, Harris A, Vasey P, Beijnen JH, Schellens JH, Burgess M, Aarons L. A population pharmacokinetic model for paclitaxel in the presence of a novel P-gp modulator, Zosuquidar Trihydrochloride (LY335979). Br J Clin Pharmacol 2003; 56:46-56. [PMID: 12848775 PMCID: PMC1884334 DOI: 10.1046/j.1365-2125.2003.01826.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To develop a population pharmacokinetic model for paclitaxel in the presence of a MDR modulator, zosuquidar 3HCl. METHODS The population approach was used (implemented with NONMEM) to analyse paclitaxel pharmacokinetic data from 43 patients who received a 3-h intravenous infusion of paclitaxel (175 mg x m(-2) or 225 mg x m(-2)) alone in cycle 2 or concomitantly with the oral administration of zosuquidar 3HCl in cycle 1. RESULTS The structural pharmacokinetic model for paclitaxel, accounting for the Cremophor ELTM impact, was a three-compartment model with a nonlinear model for paclitaxel plasma clearance (CL), involving a linear decrease in this parameter during the infusion and a sigmoidal increase with time after the infusion. The final model described the effect of Zosuquidar 3HCl on paclitaxel CL by a categorical relationship. A 25% decrease in paclitaxel CL was observed, corresponding to an 1.3-fold increase in paclitaxel AUC (from 14829 microg x l(-1) x h to 19115 microg x l(-1) x h following paclitaxel 175 mg x m(-2)) when zosuquidar Cmax was greater than 350 microg x l(-1). This cut-off concentration closely corresponded to the IC50 of a sigmoidal Emax relationship (328 microg x l(-1)). A standard dose of 175 mg x m(-2) of paclitaxel could be safely combined with doses of zosuquidar 3HCl resulting in plasma concentrations known, from previous studies, to result in maximal P-gp inhibition. CONCLUSIONS This analysis provides a model which accurately characterized the increase in paclitaxel exposure, which is most likely to be due to P-gp inhibition in the bile canaliculi, in the presence of zosuquidar 3HCl (Cmax > 350 microg x l(-1)) and is predictive of paclitaxel pharmacokinetics following a 3 h infusion. Hence the model could be useful in guiding therapy for paclitaxel alone and also for paclitaxel administered concomitantly with a P-gp inhibitor, and in designing further clinical trials.
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Callies S, de Alwis DP, Wright JG, Sandler A, Burgess M, Aarons L. A population pharmacokinetic model for doxorubicin and doxorubicinol in the presence of a novel MDR modulator, zosuquidar trihydrochloride (LY335979). Cancer Chemother Pharmacol 2003; 51:107-18. [PMID: 12647011 DOI: 10.1007/s00280-002-0542-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Accepted: 10/10/2002] [Indexed: 11/30/2022]
Abstract
PURPOSE To develop a population pharmacokinetic model for doxorubicin and doxorubicinol in the presence of zosuquidar.3HCl, a potent P-glycoprotein inhibitor. METHODS The population approach was used (implemented with NONMEM) to analyse doxorubicin-doxorubicinol pharmacokinetic data from 40 patients who had received zosuquidar.3HCl and doxorubicin intravenously (separately in cycle 1 and concomitantly in cycle 2 over 48 h and 0.5 h, respectively). RESULTS A five-compartment pharmacokinetic model (including three compartments for doxorubicin pharmacokinetics with two pathways for doxorubicinol formation) best described the doxorubicin-doxorubicinol pharmacokinetics in the presence of zosuquidar.3HCl. Doxorubicin clearance (CL), peripheral volume of distribution (V2) and doxorubicinol apparent clearance (CLm/fm) and apparent volume of distribution (Vm/fm) were 62.3 l/h, 2360 l, 143 l/h and 3150 l, respectively, in the absence or presence of low doses of zosuquidar.3HCl (<500 mg). In the presence of high doses of zosuquidar.3HCl (>or=500 mg), these values decreased by 25%, 26%, 48% and 73%, respectively, and doxorubicinol pharmacokinetics were characterized by a delayed t(max) (24 h versus 4 h), which led to the inclusion of the parallel pathways. A decrease in the objective function ( P<0.005) was observed when the impact of zosuquidar.3HCl was accounted for. CONCLUSIONS This integrated parent-metabolite population pharmacokinetic model accurately characterized the increase in doxorubicin and doxorubicinol exposure (1.33- and 2-fold, respectively) in the presence of zosuquidar.3HCl (>or=500 mg) and provided insights into the pharmacokinetic interaction, which may be useful in designing future clinical trials.
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Dantzig AH, de Alwis DP, Burgess M. Considerations in the design and development of transport inhibitors as adjuncts to drug therapy. Adv Drug Deliv Rev 2003; 55:133-50. [PMID: 12535578 DOI: 10.1016/s0169-409x(02)00175-8] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
With the realization of the importance of drug efflux transporters in disease processes and treatment, development of inhibitors to these transporters has been sought for use as adjuncts to therapy. To date, inhibitors that have been best studied are modulators of P-glycoprotein, a transporter important in the removal of anticancer agents from cells and overexpression of this transporter results in multidrug resistance. There is a delicate balance between efficacy and toxicity. This review summarizes key learning points in the development of P-glycoprotein inhibitors. Topics covered include specificity of the inhibitor for the target transporter, effect on metabolism of coadministered drugs, pharmacokinetic interactions, toxicity and the salient features needed for efficacy. These points will have general application to the development of inhibitors of transporters.
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Sessa C, Weigang-Köhler K, Pagani O, Greim G, Mora O, De Pas T, Burgess M, Weimer I, Johnson R. Phase I and pharmacological studies of the cryptophycin analogue LY355703 administered on a single intermittent or weekly schedule. Eur J Cancer 2002; 38:2388-96. [PMID: 12460783 DOI: 10.1016/s0959-8049(02)00489-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
LY355703 is a synthetic derivative of the marine cryptophycins, cytotoxic agents which induce mitotic arrest by binding at the microtubule vinca binding domain. Promising preclinical features of LY355703 were the 40-400 greater potency than paclitaxel or vinca alkaloids, the broad spectrum of antitumor activity in xenografts and the antitumour activity in multidrug resistant (MDR)-expressing murine tumours. Aims of this study were to define the maximum tolerated dose (MTD) and the dose recommended for Phase II, the pattern of toxicity, the pharmacokinetic profile and to document hints of antitumour activity of LY355703 given as 2-h infusion on day 1 every 3 weeks (Study 1) or, later on, on days 1, 8 and 15 every 4 weeks (Study 2). The latter weekly regimen was selected because of the acute dose-related toxicity reported in Study 1. The dose was escalated using a modified Continual Reassessment Method. Pharmacokinetic studies were performed on day 1 of cycle 1 in both studies; LY355703 plasma concentrations were assessed by liquid chromatography with tandem mass spectrometry. A total of 35 adult patients with solid tumours entered Study 1; the dose was escalated from 0.1 to 1.92 mg/m(2); at this dose 2 of 5 patients presented grade 3 neuropathy and myalgias; 1.48 mg/m(2) was then recommended for Phase II study. A total of 8 patients were treated in Study 2 at 1 mg/m(2); cumulative long-lasting neuroconstipation and neurosensory toxicity precluded the completion of the cycle in 9 out of 15 cycles; the clinical development of the weekly regimen was then discontinued. Other toxicities included cardiac dysrhythmia and mild alopecia. Pharmacokinetics of LY355703 appeared to be linear over the dose range studied. The administration of LY355703 on a 3-week schedule is associated with an acute dose-dependent peripheral neuropathy and myalgia of high interpatient variability for which possible risk factors and pharmacokinetic correlates could not be identified.
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Rubin EH, de Alwis DP, Pouliquen I, Green L, Marder P, Lin Y, Musanti R, Grospe SL, Smith SL, Toppmeyer DL, Much J, Kane M, Chaudhary A, Jordan C, Burgess M, Slapak CA. A phase I trial of a potent P-glycoprotein inhibitor, Zosuquidar.3HCl trihydrochloride (LY335979), administered orally in combination with doxorubicin in patients with advanced malignancies. Clin Cancer Res 2002; 8:3710-7. [PMID: 12473580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
PURPOSE The purpose of this study was to investigate the safety and tolerability of Zosuquidar.3HCl, a potent inhibitor of P-glycoprotein (Pgp), when administered p.o. alone and in combination with doxorubicin and to determine whether Zosuquidar.3HCl affects doxorubicin pharmacokinetics and inhibits Pgp function in peripheral blood natural killer lymphocytes. EXPERIMENTAL DESIGN Patients with advanced nonhematological malignancies were eligible for this Phase I trial. Zosuquidar.3HCl and doxorubicin were administered separately during the first cycle of therapy and then administered concurrently. Zosuquidar.3HCl was administered over 4 days, with doses escalated until the occurrence of dose-limiting toxicity. Subsequently, doxorubicin doses were increased from 45 to 75 mg/m(2). Zosuquidar.3HCl, doxorubicin, and doxorubicinol pharmacokinetics were analyzed, and dual fluorescence cytometry was used to determine the effects of Zosuquidar.3HCl on Pgp function in natural killer cells. RESULTS A total of 38 patients were treated at nine dose levels. Neurotoxicity was dose-limiting for oral Zosuquidar.3HCl, characterized by cerebellar dysfunction, hallucinations, and palinopsia. The maximum-tolerated dose for oral Zosuquidar.3HCl administered every 12 h for 4 days is 300 mg/m(2). Zosuquidar.3HCl did not affect doxorubicin myelosuppression or pharmacokinetics, and Zosuquidar.3HCl pharmacokinetics were similar in the absence and presence of doxorubicin. Higher plasma concentrations of Zosuquidar.3HCl were associated with greater Pgp inhibition in natural killer cells. CONCLUSION Zosuquidar.3HCl can be coadministered with doxorubicin using a 4-day oral dosing schedule, with little effect on doxorubicin toxicity or pharmacokinetics. Further refinement in Zosuquidar.3HCl dosing and scheduling should be explored to optimize Pgp inhibition while minimizing cerebellar toxicity.
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Kaufman P, Burgess M, Rutz D, Glenister C. Population Dynamics of Manure Inhabiting Arthropods Under an Integrated Pest Management (IPM) Program in New York Poultry Facilities—3 Case Studies. J APPL POULTRY RES 2002. [DOI: 10.1093/japr/11.1.90] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Romanovsky V, Burgess M, Smith S, Yoshikawa K, Brown J. Permafrost temperature records: Indicators of climate change. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2002eo000402] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Burgess M, Millane T, Deiraniya A. Acute thrombosis in an aortic prosthesis: all mechanical valves are not the same. HOSPITAL MEDICINE (LONDON, ENGLAND : 1998) 2001; 62:788-9. [PMID: 11810743 DOI: 10.12968/hosp.2001.62.12.1712] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 65-year-old man presented with symptomatic aortic valve disease and underwent aortic valve replacement with a 21 mm Hall—Kaster valve. Warfarin was commenced, and an international normalized ratio (INR) of 2.5—4.0 was recommended. Twelve years later, the patient developed a large (10 cm) ascending aortic aneurysm not involving the descending aorta. Graft replacement of the ascending aorta was performed. Inspection of the prosthesis at that time revealed it to be clean and competent, although the aortic root was heavily calcified. Eight months later, the patient was re-admitted in extremis with acute dyspnoea. For the preceding 48 hours, the intermittent absence of valve clicks had been reported by the patient's daughter. The INR on admission was 2.5 and had ranged between 2.0 and 3.6 for the 3 months before presentation. It had not been below 2.0 for at least 4 years, but on six out of the last 20 visits to the anticoagulant clinic it had been between 2.0 and 2.5. Examination revealed cardiogenic shock with a to-and-fro murmur audible at the left sternal edge. Transoesophageal echocardiography revealed free aortic regurgitation and showed thrombosis of the valve elements. Emergency surgery was considered but deemed inappropriate since the patient was moribund. Thrombolysis was attempted but the patient deteriorated relentlessly. Post-mortem confirmed the clinical impression of prosthetic valve thrombosis with no evidence of primary mechanical failure, pannus overgrowth or endocarditis (Figure 1).
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Fearn SJ, Pole R, Burgess M, Ray SG, Hooper TL, McCollum CN. Cerebral embolisation during modern cardiopulmonary bypass. Eur J Cardiothorac Surg 2001; 20:1163-7. [PMID: 11717022 DOI: 10.1016/s1010-7940(01)00981-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Cerebral microembolisation still occurs during cardiopulmonary bypass and may cause both stroke and postoperative cognitive impairment. We investigated the frequency of cerebral embolisation during coronary artery bypass surgery with modern cardiopulmonary bypass and related these to ascending aortic atherosclerosis. METHODS Transcranial Doppler monitoring for cerebral embolisation to both middle cerebral arteries was performed in 65 patients undergoing coronary artery surgery with non-pulsatile alpha-stat hypothermic bypass. Epicardial ultrasound imaging of ascending aortic atherosclerosis was performed in 14 patients. RESULTS Thirty patients (56.9%) had more than 200 emboli entering the middle cerebral artery territories during surgery; most at the start of bypass and during defibrillation. Readjustment of aortic clamps and aortic cannulation also caused a large number of emboli which were probably particulate. Aortic disease was mild (mean plaque thickness 1 mm, interquartile range 0.9-1.2 mm) and did not relate to the number of cerebral emboli produced by aortic manipulation. CONCLUSIONS Cerebral embolisation remains common during coronary surgery despite advances in filter and bypass pump technology. Aortic manipulation and clamping was associated with emboli but epicardial ultrasound imaging was of little help in its prediction.
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Tucker AW, Isaacs D, Burgess M. Cost-effectiveness analysis of changing from live oral poliovirus vaccine to inactivated poliovirus vaccine in Australia. Aust N Z J Public Health 2001; 25:411-6. [PMID: 11688618 DOI: 10.1111/j.1467-842x.2001.tb00648.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE Estimate the economic impact of introducing inactivated poliovirus vaccine (IPV) into the Australian childhood immunisation schedule to eliminate vaccine-associated paralytic poliomyelitis (VAPP). METHODS Cost-effectiveness of two different four-dose IPV schedules (monovalent vaccine and IPV-containing combination vaccine) compared with the current four-dose oral poliovirus vaccine (OPV) schedule for Australian children through age six years. Model used estimates of VAPP incidence, costs, and vaccine utilisation and price obtained from published and unpublished sources. Main outcome measures were total costs, outcomes prevented, and incremental cost-effectiveness, expressed as net cost per case of VAPP prevented. RESULTS Changing to an IPV-based schedule would prevent 0.395 VAPP cases annually. At $20 per dose for monovalent vaccine and $14 per dose for the IPV component in a combination vaccine, the change would incur incremental, annual costs of $19.5 million ($49.3 million per VAPP case prevented) and $6.7 million ($17.0 million per VAPP case prevented), respectively. Threshold analysis identified break-even prices per dose of $1 for monovalent and $7 for combination vaccines. CONCLUSIONS Introducing IPV into the Australian childhood immunisation schedule is not likely to be cost-effective unless it comes in a combined vaccine with the IPV-component price below $10. IMPLICATIONS More precise estimates of VAPP incidence in Australia and IPV price are needed. However, poor cost-effectiveness will make the decision about switching from OPV to IPV in the childhood schedule difficult.
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Aziz T, Saad RA, Burgess M, Yonan N, Hasleton P, Hutchinson IV. Transforming growth factor beta and myocardial dysfunction following heart transplantation. Eur J Cardiothorac Surg 2001; 20:177-86. [PMID: 11423293 DOI: 10.1016/s1010-7940(01)00719-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE We analyzed the role of transforming growth factor-beta (TGF-beta), a fibrogenic cytokine, in the development of left ventricular diastolic dysfunction following heart transplantation. METHODS We studied 152 heart transplant recipients who had survived for at least 24 months. We compared histopathological findings (staining of endomyocardial biopsy specimens using Hematoxylin Eosin and polyclonal antibodies), left ventricular function (Doppler echocardiography) and clinical course (NYHA status). Patients are classified into group A (n=56 recipients) with immunohistochemical TGF-beta staining score >7 and group B (n=96 recipients) with a staining score <7. RESULTS Doppler echocardiographic evaluation demonstrated greater impairment of left ventricular diastolic function in recipients with higher TGF-beta staining score. The average mitral deceleration time was 129+/-6 ms for recipients group A compared to 167+/-15 ms in group B. While the mean isovolumic relaxation time was 65+/-8 ms for patients in group A compared with 82+/-6 ms for recipients in group B (P=0.0004 and 0.005, respectively). Immunohistochemical scoring correlated inversely with both mitral deceleration and isovolumic relaxation times (r=-0.74, P=0.0004 and r=-0.66, P=0.004, respectively). Mean NYHA status was 2.7+/-1.3 for group A compared to 1.17+/-0.4 in group B was (P=0.002). Five years follow-up revealed persistent left ventricular diastolic impairment for recipients with higher immunohistochemical staining score. Mitral deceleration time and isovolumic relaxation time were 118+/-11 and 62+/-7 ms for group A compared to 156+/-12 and 80+/-5 ms for group B, P=0.006 and P=0.01, respectively. The actuarial development of subsequent coronary artery disease (> 50% stenosis) was 17 and 29% for recipients in group A compared to 4 and 6% for recipients in group B at 3 and 5 years follow-up, respectively (P=0.01 and P=0.005, respectively). CONCLUSIONS TGF-beta expression in cardiac allografts is associated with impaired graft function and limited survival. The pathogenesis of diastolic dysfunction may be an aberrant repair process following rejection due to increased TGF-beta expression in transplant recipients.
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Aziz T, Burgess M, Rahman AN, Campbell CS, Yonan N. Cardiac transplantation for cardiomyopathy and ischemic heart disease: differences in outcome up to 10 years. J Heart Lung Transplant 2001; 20:525-33. [PMID: 11343979 DOI: 10.1016/s1053-2498(00)00327-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Ischemic heart disease (IHD) and cardiomyopathy (CM) are the most common indications for heart transplantation. The aim of this study was to investigate the difference in clinical outcome between these two groups. METHODS At our institution between 1987 and 1998 transplantation was performed in 133 patients with IHD and 87 with CM. Follow-up was complete for all patients (mean 87 months). RESULTS Mean age at time of surgery was 51 +/- 5 years for IHD versus 39 +/- 9 years for CM recipients (p = 0.02). There was no difference in donor age, donor gender, or pre-operative hemodynamics between the two groups. The operative mortality was 11.2% in IHD recipients and 10.6% in CM recipients (p = 0.9). No differences were observed in intra-cardiac pressures or incidence of renal dysfunction, infection, or malignancy between the two groups. The incidence of peripheral vascular incidents was significantly higher for IHD recipients (13% vs 3%, p = 0.02). At 10 years, the incidence of coronary artery disease was 35% and 9%, respectively (p = 0.02). Mean NYHA status was 2.0 +/- 0.3 and 1.1 +/- 0.2 for IHD and CM recipients, respectively (p = 0.013). The actuarial survival at 1, 5, and 10 years was 77%, 62%, and 39% for IHD recipients compared with 85%, 82%, and 80% for CM recipients (p = 0.7, p < 0.0001 and p < 0.0001, respectively). CONCLUSION After heart transplantation, medium- and long-term outcome is significantly better for CM than IHD recipients. In view of limited donor availability, it is appropriate to explore more vigorously alternative treatments for patients with severe ischemic left ventricular dysfunction.
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Aziz TM, Burgess M, Hasleton PS, Yonan N, Deiraniya AK, Hutchinson IV. Transforming growth factor-beta: association with arteriosclerosis and left ventricular dysfunction after heart transplantation. Transplant Proc 2001; 33:2334-6. [PMID: 11377551 DOI: 10.1016/s0041-1345(01)02013-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Gillenwater AM, Hessel AC, Morrison WH, Burgess M, Silva EG, Roberts D, Goepfert H. Merkel cell carcinoma of the head and neck: effect of surgical excision and radiation on recurrence and survival. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2001; 127:149-54. [PMID: 11177031 DOI: 10.1001/archotol.127.2.149] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Merkel cell carcinoma is a rare malignant neoplasm of the skin that most often arises in the head and neck region. Despite the innocuous appearance of the primary lesion, Merkel cell carcinoma often has an aggressive clinical course with frequent locoregional recurrences and distant metastases. We evaluated the association of the width of surgical margins and the use of postoperative radiation therapy with locoregional control and survival rates. METHODS The medical records of 66 patients with head and neck Merkel cell carcinoma seen between 1945 and 1995 were retrospectively reviewed. The Fisher exact test was used to compare outcomes. Kaplan-Meier survival curves were constructed. RESULTS Eighteen patients for whom there was adequate information were divided into the following groups according to the width of their surgical margins: smaller than 1 cm, 1 to 2 cm, and larger than 2 cm. No statistical difference in locoregional control or survival was found among these groups owing to the small patient population. In contrast, a comparison of the patients who did (n = 26) and did not (n = 34) receive postoperative radiation therapy revealed a significant difference in local (3 [12%] vs 15 [44%], respectively; P<.01) and regional (7 [27%] vs 29 [85%], respectively; P<.01) recurrence rates. There was, however, no significant difference in the disease-specific survival between these groups (P = .30). Distant disease developed in 36% of all patients regardless of therapy. CONCLUSIONS Any effect of the width of surgical margins on outcome was not detectable in the small number of patients analyzed. The use of postoperative radiation therapy was associated with a significant improvement in locoregional control. There was no detectable influence of the type of initial therapy on the rates of distant metastases or on survival. Future therapeutic innovations should be directed toward controlling the development of distant metastases in patients with Merkel cell carcinoma.
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