659 research outputs found
Toward a document evaluation methodology: What does research tell us about the validity and reliability of evaluation methods?
Although the usefulness of evaluating documents has become generally accepted among communication professionals, the supporting research that puts evaluation practices empirically to the test is only beginning to emerge. This article presents an overview of the available research on troubleshooting evaluation methods. Four lines of research are distinguished concerning the validity of evaluation methods, sample composition, sample size, and the implementation of evaluation results during revisio
Concise review: Clinical relevance of drug drug and herb drug interactions mediated by the ABC transporter ABCB1 (MDR1, P-glycoprotein).
Learning Objectives
After completing this course, the reader will be able to: Identify important sources of variability in drug exposure caused by drug interactions mediated by P-glycoprotein.Describe how unwanted drug–drug interactions may lead to unexpected serious toxicity or undertreatment.Prevent these interactions by individualizing pharmacotherapy; this means selecting noninteracting drugs or adapting the dose of (the) interacting drug(s).
CME Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.co
Adduct-specific monoclonal antibodies for the measurement of cisplatin-induced DNA lesions in individual cell nuclei
The anticancer drug cisplatin executes its cytotoxic activity via formation of intra- and interstrand crosslinks in DNA. The relative contribution of structurally defined cisplatin adducts to induce apoptosis and the cellular processing of these lesions is still poorly understood mostly due to the lack of sensitive analytical tools for in vivo studies. Here we describe a new method to establish and characterize monoclonal antibodies (Mab) for structurally defined DNA adducts. The two major reaction products of cisplatin, the guanine–guanine (Pt-[GG]) and adenine–guanine (Pt-[AG]) intrastrand crosslinks are recognized by Mab R-C18 and R-B3, respectively. Both antibodies were employed in an immuno-cytological assay allowing the quantification of drug-induced lesions in individual cell nuclei at clinically relevant doses. Analyzing various tissues of cisplatin-treated C57Bl/6 mice the accumulation of Pt-(GG) was highest in kidney tubular cells compared with 30, 50 and 90% lower levels in kidney stroma, liver and peripheral blood cells, respectively. Adduct kinetics revealed that wild type mouse cells remove up to 80% of the crosslinks in contrast to their complete persistence in nucleotide excision repair-deficient (XPC(−/−)) mice. The aptitude of the immunoassay for human molecular dosimetry studies was demonstrated by measuring adduct levels in tumor biopsies from patients treated with cisplatin
Comparison of ethanol plasma-protein precipitation with plasma ultrafiltration and trichloroacetic acid protein precipitation for the measurement of unbound platinum concentrations
Sensitive high-performance liquid chromatographic fluorescence assay for the quantitation of topotecan (SKF 104864-A) and its lactone ring-opened product (hydroxy acid) in human plasma and urine
A sensitive reversed-phase high-performance liquid chromatographic fluorescence method is described for the simultaneous determination of topotecan (I) and the hydrolysed lactone ring-opened product hydroxy acid (II) in plasma and for the determination of I in urine. To 250 μl of plasma, a 750-μl volume of cold methanol was added to stabilize the pH-dependent conversion of I into II. In plasma, the lower limit of quantitation (LLQ) for both compounds was 0.10 ng/ml. The between-day variation for I at the LLQ was 7.1% and for II was 5.5%. Prior to injection, urine samples were acidified with orthophosphoric acid and diluted with phosphate-buffered saline (PBS). In urine, the calibration curve for I was linear in the range of 10 to 250 ng/ml and the LLQ was 10 ng/ml. The assay was developed to enable pharmacological analysis of I, in on-going phase I and II studies, in patients with solid tumors
Archeologische prospectie met ingreep in de bodem Ranst, Oelegem, Schuurblok
Dit rapport werd ingediend bij het agentschap samen met een aantal afzonderlijke digitale bijlagen. Een aantal van deze bijlagen zijn niet inbegrepen in dit pdf document en zijn niet online beschikbaar. Sommige bijlagen (grondplannen, fotos, spoorbeschrijvingen, enz.) kunnen van belang zijn voor een betere lezing en interpretatie van dit rapport. Indien u deze bijlagen wenst te raadplegen kan u daarvoor contact opnemen met: [email protected]
Specific Investigation of Sample Handling Effects on Protease Activities and Absolute Serum Concentrations of Various Putative Peptidome Cancer Biomarkers
# The Author(s) 2010. This article is published with open access at Springerlink.com Introduction In the search for novel cancer biomarkers, various proteolytically derived peptides have been proposed to exhibit cancer or cancer-type specificity. As these peptides are presumably also generated after sample collection by tumor-specific proteases, extensive investigatio
Emerging and scripted roles in computer-supported collaborative learning
Emerging and scripted roles pose an intriguing approach to analysing and facilitating CSCL. The concept of emerging roles provides a perspective on how learners structure and self-regulate their CSCL processes. Emerging roles appear to be dynamic over longer periods of time in relation to learners’ advancing knowledge, but are often unequally distributed in ad hoc CSCL settings, e.g. a learner being the ‘typist’ and another being the ‘thinker’. Empirical findings show that learners benefit from structuring or scripting CSCL. Scripts can specify roles and facilitate role rotation for learners to equally engage in relevant learning roles and activities. Scripted roles can, however, collide with emerging roles and therefore need to be carefully attuned to the advancing capabilities of the learners
The impact of structural uncertainty on cost-effectiveness models for adjuvant endocrine breast cancer treatments: The need for disease-specific model standardization and improved guidance
__Abstract__
Introduction: Structural uncertainty relates to differences in model structure and parameterization. For many published health economic analyses in oncology, substantial differences in model structure exist, leading to differences in analysis outcomes and potentially impacting decision-making processes. The objectives of this analysis were (1) to identify differences in model structure and parameterization for cost-effectiveness analyses (CEAs) comparing tamoxifen and anastrazole for adjuvant breast cancer (ABC) treatment; and (2) to quantify the impact of these differences on analysis outcome metrics. Methods: The analysis consisted of four steps: (1) review of the literature for identification of eligible CEAs; (2) definition and implementation of a base model structure, which included the core structural components for all identified CEAs; (3) definition and implementation of changes or additions in the base model structure or parameterization; and (4) quantification of the impact of changes in model structure or parameterizations on the analysis outcome metrics life-years gained (LYG), incremental costs (IC) and the incremental cost-effectiveness ratio (ICER). Results: Eleven CEA analyses comparing anastrazole and tamoxifen as ABC treatment were identified. The base model consisted of the following health states: (1) on treatment; (2) off treatment; (3) local recurrence; (4) metastatic disease; (5) death due to breast cancer; and (6) death due to other causes. The base model estimates of anastrazole versus tamoxifen for the LYG, IC and ICER were 0.263 years, €3,647 and €13,868/LYG, respectively. In the published models that were evaluated, differences in model structure included the addition of different recurrence health states, and associated transition rates were identified. Differences in parameterization were related to the incidences of recurrence, local recurrence to metastatic disease, and metastatic disease to death. The separate impact of these model components on the LYG ranged from 0.207 to 0.356 years, while incremental costs ranged from €3,490 to €3,714 and ICERs ranged from €9,804/LYG to €17,966/LYG. When we re-analyzed the published CEAs in our framework by including their respective model properties, the LYG ranged from 0.207 to 0.383 years, IC ranged from €3,556 to €3,731 and ICERs ranged from €9,683/LYG to €17,570/LYG. Conclusion:
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