The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Jos H Beijnen - One of the best experts on this subject based on the ideXlab platform.
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determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry
Veterinary and Comparative Oncology, 2015Co-Authors: Tine Janssens, E E M Brouwers, N De Vries, Jan H M Schellens, Jos H BeijnenAbstract:The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology centres, 46.3 and 68.9% of the sampled surfaces demonstrated platinum contamination, respectively. Highest platinum levels were found in the preparation rooms (44.6 pg cm-2) in veterinary centres, while maximal levels in human centres were found in oncology patient-only toilets (725 pg cm-2). Transference of platinum by workers outside areas where antineoplastic drugs were handled was observed in veterinary and human oncology centres. In conclusion, only low levels of platinum contamination attributable to carboplatin were found in the sampled veterinary oncology centres. However, dispersion of platinum outside areas where antineoplastic drugs were handled was detected in veterinary and human oncology centres. Consequently, not only personnel, but also others may be exposed to platinum.
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Monitoring of platinum surface contamination in seven Dutch hospital pharmacies using inductively coupled plasma mass spectrometry
International Archives of Occupational and Environmental Health, 2007Co-Authors: E E M Brouwers, Jan H M Schellens, A. D. R. Huitema, E. N. Bakker, J. W. Douma, K. J. M. Schimmel, G. Weringh, P. J. Wolf, Jos H BeijnenAbstract:Objective: To develop, validate, and apply a method for the determination of platinum contamination, originating from cisplatinum, oxaliplatinum, and carboplatinum. Methods: Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine platinum in wipe samples. The sampling procedure and the analytical conditions were optimised and the assay was validated. The method was applied to measure surface contamination in seven Dutch hospital pharmacies. Results: The developed method allowed reproducible quantification of 0.50 ng l^−1 platinum (5 pg/wipe sample). Recoveries for stainless steel and linoleum surfaces ranged between 50.4 and 81.4% for the different platinum compounds tested. Platinum contamination was reported in 88% of the wipe samples. Although a substantial variation in surface contamination of the pharmacies was noticed, in most pharmacies, the laminar-airflow (LAF) hoods, the floor in front of the LAF hoods, door handles, and handles of service hatches showed positive results. This demonstrates that contamination is spread throughout the preparation rooms. Conclusion: We developed and validated an ultra sensitive and reliable ICP-MS method for the determination of platinum in surface samples. Surface contamination with platinum was observed in all hospital pharmacies sampled. The interpretation of these results is, however, complicated.
David R Gandara - One of the best experts on this subject based on the ideXlab platform.
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relevance of platinum sensitivity status in relapsed refractory extensive stage small cell lung cancer in the modern era a patient level analysis of southwest oncology group trials
Journal of Thoracic Oncology, 2015Co-Authors: Primo N Lara, James Moon, Mary W Redman, Thomas J Semrad, Karen Kelly, J W Allen, Barbara J Gitlitz, Philip C Mack, David R GandaraAbstract:Extensive-stage small-cell lung cancer (SCLC) patients who progress after platinum-based chemotherapy are traditionally categorized as platinum sensitive (progression ≥ 90 days from last platinum dose) or refractory (progression < 90 days), a practice arising from seminal observations of worse survival in refractory patients. Subsequent trials accounted for platinum sensitivity, resulting in higher sample sizes and increased resource use.To assess whether platinum-sensitivity status remains associated with outcomes, patient-level data from recent Southwest Oncology Group trials in second- and/or third-line extensive-stage SCLC were pooled. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) accounting for platinum sensitivity were calculated using unadjusted and adjusted Cox Proportional Hazard models. Recursive partitioning was performed to define prognostic risk groups.Of 329 patients, 151 were platinum sensitive and 178 refractory. HRs from unadjusted Cox PFS and OS models for refractory versus sensitive disease were 1.0 (95% confidence interval, 0.81-1.25; p = 0.98) and 1.24 (0.99-1.57; p = 0.06), respectively. Adjusted Cox models showed that only elevated serum lactate dehydrogenase (HR, 2.04; p < 0.001), males (HR, 1.36; p = 0.04), performance status of 1 (HR, 1.25; p = 0.02), and weight loss greater than or equal to 5% (1.53, p = 0.01) were independently associated with OS. Platinum-sensitivity status was not associated with PFS (HR, 1.11; p = 0.49) or OS (HR, 1.25; p = 0.14), except in a model that excluded 36 patients who received more than one prior chemotherapy regimen (HR, 1.34; p = 0.049). Prognostic groups with differential OS outcomes (high, intermediate, and poor risk) were identified.Platinum-sensitivity status may no longer be strongly associated with PFS or OS in at least one multivariate model. Validation of prognostic risk groups identified here is warranted. These data have critical implications in the design of future SCLC trials.
Florian Mansfeld - One of the best experts on this subject based on the ideXlab platform.
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EMBC - Electrodeposition of platinum-iridium alloy nanowires for hermetic packaging of microelectronics
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2012Co-Authors: Artin Petrossians, James D. Weiland, James J. Whalen, Florian MansfeldAbstract:An electrodeposition technique was applied for fabrication of dense platinum-iridium alloy nanowires as interconnect structures in hermetic microelectronic packaging to be used in implantable devices. Vertically aligned arrays of platinum-iridium alloy nanowires with controllable length and a diameter of about 200 nm were fabricated using a cyclic potential technique from a novel electrodeposition bath in nanoporous aluminum oxide templates. Ti/Au thin films were sputter deposited on one side of the alumina membranes to form a base material for electrodeposition. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to characterize the morphology and the chemical composition of the nanowires, respectively. SEM micrographs revealed that the electrodeposited nanowires have dense and compact structures. EDS analysis showed a 60∶40% platinum-iridium nanowire composition. Deposition rates were estimated by determining nanowire length as a function of deposition time. High Resolution Transmission Electron Microscopy (HRTEM) images revealed that the nanowires have a nanocrystalline structure with grain sizes ranging from 3 nm to 5 nm. Helium leak tests performed using a helium leak detector showed leak rates as low as 1 × 10−11 mbar L s−1 indicating that dense nanowires were electrodeposited inside the nanoporous membranes. Comparison of electrical measurements on platinum and platinum-iridium nanowires revealed that platinum-iridium nanowires have improved electrical conductivity.
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Electrodeposition of platinum-iridium alloy nanowires for hermetic packaging of microelectronics
2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012Co-Authors: Artin Petrossians, James D. Weiland, James J. Whalen, Florian MansfeldAbstract:An electrodeposition technique was applied for fabrication of dense platinum-iridium alloy nanowires as interconnect structures in hermetic microelectronic packaging to be used in implantable devices. Vertically aligned arrays of platinum-iridium alloy nanowires with controllable length and a diameter of about 200 nm were fabricated using a cyclic potential technique from a novel electrodeposition bath in nanoporous aluminum oxide templates. Ti/Au thin films were sputter deposited on one side of the alumina membranes to form a base material for electrodeposition. Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) were used to characterize the morphology and the chemical composition of the nanowires, respectively. SEM micrographs revealed that the electrodeposited nanowires have dense and compact structures. EDS analysis showed a 60:40% platinum-iridium nanowire composition. Deposition rates were estimated by determining nanowire length as a function of deposition time. High Resolution Transmission Electron Microscopy (HRTEM) images revealed that the nanowires have a nanocrystalline structure with grain sizes ranging from 3 nm to 5 nm. Helium leak tests performed using a helium leak detector showed leak rates as low as 1 × 10-11 mbar L s-1 indicating that dense nanowires were electrodeposited inside the nanoporous membranes. Comparison of electrical measurements on platinum and platinum-iridium nanowires revealed that platinum-iridium nanowires have improved electrical conductivity.
Jan H M Schellens - One of the best experts on this subject based on the ideXlab platform.
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determination of platinum surface contamination in veterinary and human oncology centres using inductively coupled plasma mass spectrometry
Veterinary and Comparative Oncology, 2015Co-Authors: Tine Janssens, E E M Brouwers, N De Vries, Jan H M Schellens, Jos H BeijnenAbstract:The objective of this study was to determine the surface contamination with platinum-containing antineoplastic drugs in veterinary and human oncology centres. Inductively coupled plasma mass spectrometry was used to measure platinum levels in surface samples. In veterinary and human oncology centres, 46.3 and 68.9% of the sampled surfaces demonstrated platinum contamination, respectively. Highest platinum levels were found in the preparation rooms (44.6 pg cm-2) in veterinary centres, while maximal levels in human centres were found in oncology patient-only toilets (725 pg cm-2). Transference of platinum by workers outside areas where antineoplastic drugs were handled was observed in veterinary and human oncology centres. In conclusion, only low levels of platinum contamination attributable to carboplatin were found in the sampled veterinary oncology centres. However, dispersion of platinum outside areas where antineoplastic drugs were handled was detected in veterinary and human oncology centres. Consequently, not only personnel, but also others may be exposed to platinum.
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Monitoring of platinum surface contamination in seven Dutch hospital pharmacies using inductively coupled plasma mass spectrometry
International Archives of Occupational and Environmental Health, 2007Co-Authors: E E M Brouwers, Jan H M Schellens, A. D. R. Huitema, E. N. Bakker, J. W. Douma, K. J. M. Schimmel, G. Weringh, P. J. Wolf, Jos H BeijnenAbstract:Objective: To develop, validate, and apply a method for the determination of platinum contamination, originating from cisplatinum, oxaliplatinum, and carboplatinum. Methods: Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine platinum in wipe samples. The sampling procedure and the analytical conditions were optimised and the assay was validated. The method was applied to measure surface contamination in seven Dutch hospital pharmacies. Results: The developed method allowed reproducible quantification of 0.50 ng l^−1 platinum (5 pg/wipe sample). Recoveries for stainless steel and linoleum surfaces ranged between 50.4 and 81.4% for the different platinum compounds tested. Platinum contamination was reported in 88% of the wipe samples. Although a substantial variation in surface contamination of the pharmacies was noticed, in most pharmacies, the laminar-airflow (LAF) hoods, the floor in front of the LAF hoods, door handles, and handles of service hatches showed positive results. This demonstrates that contamination is spread throughout the preparation rooms. Conclusion: We developed and validated an ultra sensitive and reliable ICP-MS method for the determination of platinum in surface samples. Surface contamination with platinum was observed in all hospital pharmacies sampled. The interpretation of these results is, however, complicated.
Trevor W Hambley - One of the best experts on this subject based on the ideXlab platform.
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The cellular distribution and oxidation state of platinum(II) and platinum(IV) antitumour complexes in cancer cells
Journal of Biological Inorganic Chemistry, 2003Co-Authors: Matthew D. Hall, Carolyn T. Dillon, Philip Beale, Anton P. J. Stampfl, Mei Zhang, Trevor W HambleyAbstract:The cellular distribution of platinum in A2780 ovarian cancer cells treated with cisplatin and platinum(IV) complexes with a range of reduction potentials has been examined using elemental analysis (synchrotron radiation-induced X-ray emission). The cellular distribution of platinum(IV) drugs after 24 h is similar to that of cisplatin, consistent with the majority of administered platinum(IV) drugs being reduced. Micro-X-ray absorption near-edge spectra of cells treated with cisplatin and platinum(IV) complexes confirmed the reduction of platinum(IV) to platinum(II). In cells treated, the most difficult to reduce complex, cis,trans,cis-[PtCl2(OH)2(NH3)2], platinum(IV) was detected in the cells along with platinum(II). The observations are in accordance with the relative ease of reduction of the platinum(IV) complexes used and support the requirement of reduction for activation of platinum(IV) complexes.
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Platinum (IV) antitumour compounds: their bioinorganic chemistry
Coordination Chemistry Reviews, 2002Co-Authors: M. D. Hall, Trevor W HambleyAbstract:This article reviews the investigations undertaken into platinum(IV) antitumour compounds since Barnett Rosenberg first noted the activity of platinum(IV) complexes. The chemical and pharmacological properties of the drugs are discussed and both the reactions with individual biomolecules, which have received attention and the characterisation of biotransformation products from animal and clinical trials are reviewed. The bioinorganic chemistry of platinum(IV) complexes has not previously been reviewed, and the purpose here is to provide insight into the requirements for the antitumour activity of platinum(IV) complexes.