High-throughput method development for sensitive, accurate, and reproducible quantification of therapeutic monoclonal antibodies in tissues using orthogonal array optimization and nano liquid chromatography/selected reaction monitoring mass spectrometry

Although liquid chromatography/mass spectrometry using selected reaction monitoring (LC/SRM-MS) holds great promise for targeted protein analysis, quantification of therapeutic monoclonal antibody (mAb) in tissues represents a daunting challenge due to the extremely low tissue levels, complexity of tissue matrixes, and the absence of an efficient strategy to develop an optimal LC/SRM-MS method. Here we describe a high-throughput, streamlined strategy for the development of sensitive, selective, and reliable quantitative methods of mAb in tissue matrixes. A sensitive nano-LC/nanospray-MS method was employed to achieve a low lower limit of quantification (LOQ). For selection of signature peptides (SP), the SP candidates were identified by a high-resolution Orbitrap and then optimal SRM conditions for each candidate were obtained using a high-throughput, on-the-fly orthogonal array optimization (OAO) strategy, which is capable of optimizing a large set of SP candidates within a single nano-LC/SRM-MS run. Using the optimized conditions, the candidates were experimentally evaluated for both sensitivity and stability in the target matrixes, and SP selection was based on the results of the evaluation. Two unique SP, respectively from the light and heavy chain, were chosen for quantification of each mAb. The use of two SP improves the quantitative reliability by gauging possible degradation/modification of the mAb. Standard mAb proteins with verified purities were utilized for calibration curves, to prevent the quantitative biases that may otherwise occur when synthesized peptides were used as calibrators. We showed a proof of concept by rapidly developing sensitive nano-LC/SRM-MS methods for quantifying two mAb (8c2 and cT84.66) in multiple preclinical tissues. High sensitivity was achieved for both mAb with LOQ ranged from 0.156 to 0.312 μg/g across different tissues, and the overall procedure showed a wide dynamic range (≥500-fold) and good accuracy [relative error (RE) < 18.8%] and precision [interbatch relative standard deviation (RSD) < 18.1%, intrabatch RSD < 17.2%]. The quantitative method was applied to a comprehensive investigation of the steady-state tissue distribution of 8c2 in wild-type mice versus those deficient in FcRn α-chain, FcγIIb, and FcγRI/FcγRIII, following a chronic dosing regimen. This work represents the first extensive quantification of mAb in tissues by an LC/MS-based method.     

A probabilistic model of wall thinning in CANDU feeders due to flow-accelerated corrosion

Wall thinning due to flow-accelerated corrosion (FAC) is a pervasive form of degradation in feeder pipes of the primary heat transport system of CANDU reactors. Prediction of the end-of-life of a feeder from wall thickness measurement data is confounded by the sampling and temporal uncertainties associated with the FAC degradation phenomenon. This paper presents a probabilistic model of wall thinning due to FAC, and calibrates it with a set of feeder wall thickness measurements obtained from a CANDU plant. The proposed model derives the feeder lifetime distribution, which is useful in developing optimum strategies for life-cycle management of the feeder system.     

Acute behavioral effects of triazolam and caffeine, alone and in combination, in humans.

The acute behavioral effects of triazolam (0, 0.375, and 0.75 mg/70 kg) and caffeine (0, 250, and 500 mg/70 kg), alone and in combination, were assessed in 9 male volunteers. Ss received all possible dose combinations according to a Latin square design. Triazolam administered alone dose dependently disrupted learning and performance on the Repeated Acquisition and Performance procedure and the Digit Symbol Substitution Test and increased S ratings of sedation. Caffeine administered alone did not significantly affect learning or performance measures, but it did dose dependently increase S ratings of drug strength. Caffeine significantly attenuated triazolam-induced decrements in learning and performance. Consistent with effects on learning and performance, caffeine offset triazolam-induced increases in S ratings of sedation. Combining caffeine and triazolam did not significantly alter increases in S ratings of drug strength observed with caffeine alone. These effects are qualitatively similar to those observed with other benzodiazepines (e.g., lorazepam) and document a high degree of consistency in the behavioral pharmacology of benzodiazepine-caffeine combinations in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of adding behavioral treatment to opioid detoxification with buprenorphine.

This trial assessed whether behavioral treatment improves outcome during a 26-week outpatient opioid detoxification. Thirty-nine opioid-dependent adults were assigned randomly to a buprenorphine dose-taper combined with either behavioral or standard treatment. Behavioral treatment included (a) a voucher incentive program for providing opioid-free urine samples and engaging in verifiable therapeutic activities and (b) the community reinforcement approach, a multicomponent behavioral treatment. Standard treatment included lifestyle counseling. Fifty-three percent of the patients receiving behavioral treatment completed treatment, versus 20% receiving standard treatment. The percentage of patients achieving 4, 8, 12, and 16 weeks of continuous opioid abstinence were 68, 47, 26, and 11 for the behavioral group and 55, 15, 5, and 0 for the standard group, respectively. Behavioral treatment improved outcomes during outpatient detoxification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Separate but equal? A comparison of participants and data gathered via Amazon’s MTurk,social media,and face-to-face behavioral testing

Recent and emerging technology permits psychologists today to recruit and test participants in more ways than ever before. But to what extent can behavioral scientists trust these varied methods to yield reasonably equivalent results? Here, we took a behavioral, face-to-face task and converted it to an online test. We compared the online responses of participants recruited via Amazon’s Mechanical Turk (MTurk) and via social media postings on Twitter, Facebook, and Reddit. We also recruited a standard sample of students on a college campus and tested them in person, not via computer interface. The demographics of the three samples differed, with MTurk participants being significantly more socio-economically and ethnically diverse, yet the test results across the three samples were almost indistinguishable. We conclude that for some behavioral tests, online recruitment and testing can be a valid—and sometimes even superior—partner to in-person data collection.     

Numerical analysis of fiber composite-steel plate upgraded beam–column sub-assemblages under cyclic loading

In the present study, exterior beam–column sub-assemblage from a regular RC building has been considered. Extremely poor gravity load designed (GLD) beam–column sub-assemblage was upgraded by combinely using FRP and steel plate. Three different upgradation schemes have been proposed. Nonlinear finite element (FE) program has been employed for analysing both existing and upgraded sub-assemblages under cyclic loading. Concrete parts of the FE models were modelled using quadratic brick – and steel plates were modelled using tetrahedral – solid elements. All the FRPs were modelled as 9-noded iso-parametric multi-layered shell elements with embedded unidirectional reinforcement to represent the anisotropic material property. Contact elements and bond properties were suitably incorporated. It has been found out that the results obtained from the numerical analysis are well corroborated with those of experimental results. Further, a detailed parametric study has been carried out on type, extent and amount of flexural strengthening, and number of wrapping to identify the scopes of improvement on the proposed upgradation schemes.     

Experimental and clinical psychopharmacology: The next five years.

I am very honored to have been selected to serve as the editor of Experimental and Clinical Psychopharmacology (ECP). I consider ECP to be an important scholarly resource for our field, and I have given considerable thought to my responsibilities as editor and to the goals I wish to accomplish. In this editorial, I outline my vision for the journal in its next 5 years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Celebrating the decade of behavior: Introduction to special issue.

This special issue represents a joint effort by the journal Experimental and Clinical Psychopharmacology and the American Psychological Association's Division of Psychopharmacology and Substance Abuse to celebrate the "Decade of Behavior: 2000–2100" initiative. The Decade of Behavior initiative seeks to underscore the importance of behavioral science to broadening understanding and offering solutions to many of society's most challenging problems. Contained in this special issue are commentaries by 3 Institute directors from the National Institutes of Health, 4 excellent critical reviews of various aspects of contemporary psychopharmacology research, and a series of 9 excellent original research reports. This series of articles bodes well for the health of psychopharmacology and substance abuse research and offers a fitting salute to this important initiative. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ein biographischer Vergleich von Medizinhistorikern im Zeitraum 1825–1975

25 medical historians born between 1800 and 1900 have been selected, mainly by citation frequency, for a study in comparative biography. They originated in Germany, U.S.A., U.K. France, Switzerland, Italy, and Austria. A number of them were active in two countries due to emigration from fascist Europe in the 1930s. All were MDs except for one historian. Most of them showed an interest in the history of medicine early in life, some only between age 40–50. Their motivations were quite varied. Most of them made their living with clinical practice, at least initially. Those ten who attained a chair in the history of medicine did so usually between age 41 and 56. Our selection of medical historians active between 1825 and 1975 is very heterogeneous, much more so than in the final decades of the 20th century.     

Modeling drug consumption in the clinic using simulation procedures: Demand for heroin and cigarettes in opioid-dependent outpatients.

Use of a time- and cost-efficient simulation procedure to assess reinforcement efficacy in humans was explored in the present study. Opioid-dependent outpatients completed questionnaires asking how many cigarettes or bags of heroin they would purchase across a range of prices. Reported consumption patterns conformed to a quantitative model that has been successful in accounting for data obtained in studies using real rather than hypothetical consequences, suggesting the self-report data may have been a valid proxy for observations of actual consumption patterns. Simulation procedures may thus be a useful supplement to traditional operant methods for the assessment of reinforcement efficacy in humans, particularly in situations where the use of operant methods is logistically difficult or ethically questionable. The relationship between behavioral-economic and traditional measures of reinforcement efficacy is also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)