News Article | April 17, 2017
The cancer profile of African-born blacks differs from that of United States-born blacks and varies by region of birth, according to a new study. The study, appearing in CANCER, suggests differences in environmental, cultural, social, and genetic factors, and points to an opportunity to study the risk factors associated with the cancer burden in African-born blacks to help create targeted interventions. Sub-Saharan African-born blacks are one of the fastest-growing populations in the United States, comprising a substantial proportion of the estimated 2.1 million black African immigrants in the United States in 2015. However, there is a lack of data regarding the cancer burden in this group. To learn more, researchers from the American Cancer Society, the Ohio State University, and Covance Laboratories reviewed incidence data covering 2000-2012 from the Surveillance, Epidemiology, and End Results (SEER 17) program to compare the frequency of the top 15 cancers in African-born blacks with that of U.S.-born blacks by sex and region of birth. Because the investigators did not have data on the number of sub-Saharan African born immigrants living in SEER areas, they were not able to estimate the incidence of cancers by place of birth, and instead examined the proportion of individual cancers among overall cancers in this group. They found that compared to United States-born non-Hispanic blacks, sub-Saharan African-born blacks had significantly higher proportion of infection-related cancers (liver, stomach, and Kaposi sarcoma), blood cancers (leukemia and non-Hodgkin lymphoma), prostate cancer, and thyroid cancers (in females only). For example, the proportion of Kaposi sarcoma was 12 times higher in African-born black women than US-born black women. In contrast, African-born black men had lower incidence for smoking-related and colorectal cancers. For example, the proportion of lung cancer was 30% lower in African-born black men compared to blacks born in the U.S. Furthermore, cancer occurrence in African-born blacks versus U.S.-born blacks varied by region of birth. For example, the higher incidence for liver cancer noted among male African-born blacks and for thyroid cancer in African-born females were confined to Eastern African-born blacks, whereas the higher incidence for prostate cancer was confined to Western African-born blacks. "Typically, cancer occurrence among blacks in the United States is presented as one homogenous group, with no breakdown by country or region of birth," said Ahemdin Jemal, D.V.M., Ph.D., American Cancer Society epidemiologist and co-author of the study. "Our study shows that approach masks important potential differences that may be key to guiding cancer prevention programs for African-born black immigrants." Article: Cancer Incidence Profile in Sub-Saharan African-Born Blacks in the United States: Similarities and Differences With US-Born Non-Hispanic Blacks; Jemal et al. CANCER; Published Online: April 13, 2017 DOI: 10.1002/cncr.30701.
Lepping M.D.,Dow AgroSciences |
Herman R.A.,Dow AgroSciences |
Potts B.L.,Covance Laboratories Inc.
Journal of Agricultural and Food Chemistry | Year: 2013
Soybeans from transgenic event DAS-444Ø6-6 are the first to express three proteins that provide tolerance to broad-spectrum herbicides. DAS-444Ø6-6 soybean expresses the aryloxyalkanoate dioxygenase-12 (AAD-12) enzyme from the soil bacterium Delftia acidovorans, which provides tolerance to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D); the double-mutant 5-enolpyruvylshikimate-3-phosphate synthase (2mEPSPS) enzyme encoded by a modified version of the epsps gene from maize (Zea mays), which provides tolerance to the herbicide glyphosate; and the phosphinothricin acetyltransferase (PAT) enzyme from Streptomyces viridochromogenes, which provides tolerance to the herbicide glufosinate. The purpose of this study was to determine if the nutrient and antinutrient composition of forage and grain from DAS-444Ø6-6 soybean are similar to those of nontransgenic soybean. Forage was analyzed for proximates, fiber, and minerals; grain analyses further included vitamins, amino acid and fatty acid profiles, and antinutrients and bioactive components (lectin, phytic acid, raffinose, stachyose, trypsin inhibitor, and isoflavones). Results indicate that DAS-444Ø6-6 soybean is compositionally equivalent to nontransgenic soybean. Findings are consistent with similar studies for other input traits, as endogenous plant metabolic pathways that influence composition are expected to be less affected by transgenesis compared with traditional plant-breeding methods. © 2013 American Chemical Society.
Jiang H.,Huazhong University of Science and Technology |
Cao H.,Covance Laboratories Inc. |
Zhang Y.,Covance Laboratories Inc. |
Fast D.M.,Covance Laboratories Inc.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012
In past a few years, there has been a large increase in the application of supported liquid extraction (SLE) for LC-MS/MS based bioanalysis due to its distinct practical advantage in reduced time cost, ease of operation and the feasibility for automation. The main purpose of this study was to systematically evaluate supported liquid extraction in reducing matrix effect and improving extraction efficiency/recovery under various extraction conditions with 10 model pharmaceutical compounds in liquid chromatography coupled to electrospray tandem mass spectrometry (LC-ESI-MS/MS) analysis. Selected compounds have diverse physicochemical properties where logP ranges from 0.1 to 6.24 and pKa ranges from 4.0 to 11.1. The factors that may have the impact on the recovery of analytes and phospholipids (PL) were assessed. Over 75% recovery was achieved for every analyte under its respectively optimized extraction conditions where the selection of the polarity of extraction solvent and buffered pH can be critical for efficient recovery. Furthermore, the matrix effect was assessed by postextraction spike and postcolumn infusion method. The matrix effect was considerably reduced for all analytes under most extraction conditions evaluated for SLE, compared with protein precipitation (PPT) method. The correlation between matrix effect and residual phospholipids in sample extract was clearly shown. Although analyte-dependent matrix effect was observed prominently in sample extract prepared by PPT, it was minimized by SLE sample preparation process that effectively removes the majority of phospholipids. Sample extracted by ethyl acetate contained more phospholipids and demonstrated stronger matrix effect than by other organic solvents. Water-miscible organic content, such as methanol and acetonitrile in samples prior to loading has significant impact on PL recovery when eluting with methyl tert-butyl ether. However, isopropanol does not enhance the recovery of PL when adding to dichloromethane for elution. In addition, the compromise between improved extraction efficiency by SLE and reduced matrix effect is sometimes necessary to yield clean extract with acceptable recovery. The effective removal of phospholipids and reduction of matrix effect, while achieving good recovery for all pharmaceutical compounds with diverse physicochemical properties, demonstrated that SLE is a valuable alternative technique to liquid-liquid extraction (LLE) in high throughput LC-MS/MS based bioanalysis. © 2012 Elsevier B.V..
Hale S.L.,Covance Laboratories Inc.
Toxicologic pathology | Year: 2011
This session at the 2010 joint symposium of the Society of Toxicologic Pathology (STP) and the International Federation of Societies of Toxicologic Pathologists (IFSTP) explored modern neuropathology methods for assessing the neurotoxicologic potential of xenobiotics. Conventional techniques to optimally prepare and evaluate the central and peripheral neural tissues while minimizing artifact were reviewed, and optimal schemes were set forth for evaluation of the nervous system during both routine (i.e., general toxicity) studies and enhanced (i.e., specialized neurotoxicity) studies. Stereology was introduced as the most appropriate means of examining the possible impact of toxicants on neural cell numbers. A focused discussion on brain sampling took place among a panel of expert neuroscientists (anatomists and pathologists) and the audience regarding the proper balance between sufficient sampling and cost- and time-effectiveness of the analysis. No consensus was reached on section orientation (coronal sections of both sides vs. a parasagittal longitudinal section with several unilateral hemisections from the contralateral side), but most panelists favored sampling at least 8 sections (or approximately double to triple the current complement) in routine toxicity studies.
Huang M.,Covance Laboratories Inc.
Journal of AOAC International | Year: 2012
In an effort to measure vitamin D, ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) was applied to samples. The use of UHPLC-MS/MS decreased the run time by 50%. The UHPLC-MS/MS achieved equal or better separation efficiency with complex food matrixes compared to HPLC-MS/MS. It was also observed that under the optimized conditions of UHPLC, all previtamins of vitamin D3, D2, and isotope-labeled vitamin D3 were baseline-separated from their corresponding vitamins. The sterol isomers found in complex food matrixes that interfere in the analysis were well separated from the analytes. The accuracy of the method was evaluated by analyzing National Institute of Standards and Technology Standard Reference Material 1849 infant reference material. The average vitamin D3 concentration was 0.251 +/- 0.012 microg/g. This showed excellent agreement with the certified value of 0.251 +/- 0.027 microg/g. The spike recovery study of a commercial infant formula matrix showed a range of recovery from 100 to 108%. The LOQ values determined were 0.0022 and 0.0028 microg/g for vitamins D3 and D2, respectively; LOD values were 0.00065 and 0.00083 microg/g for vitamins D3 and D2, respectively.
Li F.,Covance Laboratories Inc.
Journal of mass spectrometry : JMS | Year: 2012
Dried blood spot (DBS) sampling has gained considerable interest as a microsampling technique to support drug discovery and development owing to its enormous ethical and practical benefits. Quantitative determinations of drugs and/or their metabolites collected in DBS matrix in its current format, however, have encountered technical challenges and regulatory uncertainty. The challenges of DBS bioanalysis are largely ascribed to the way how samples are collected and analyzed. Currently, an uncontrolled amount of a blood sample, e.g. 20 μl, is collected per time point per sample and spotted onto cellulose paper. Quantitation is based on removal of a fixed area of the DBS sample, resulting in sample waste, a need for mechanical punching and concomitant potential punching carryover, uncertainty in recovery assessment and the adverse impact of hematocrit on accurate quantitation. Here, we describe the concept and applications of a novel concept, namely perforated dried blood spot (PDBS), for accurate microsampling that addresses previous challenges. Advantages of PDBS are enumerated and compared with conventional DBS in the context of microsampling and liquid chromatography tandem mass spectrometry bioanalysis. Two approaches for accurate microsampling of a small volume of blood (5 μl) are proposed and demonstrated, i.e. Microsafe® pipettes and the Drummond incremental pipette. Two online sample enrichment techniques to enhance liquid chromatography tandem mass spectrometry sensitivity for microsampling bioanalysis are discussed. The PDBS concept was successfully applied for accurate sample collection (5 μl) in a toxicokinetic study in rats given a single oral gavage dose of acetaminophen. Perspectives on bioanalytical method validation for regulated DBS/PDBS microsampling are also presented. Copyright © 2012 John Wiley & Sons, Ltd.
Li F.,Covance Laboratories Inc. |
Fast D.,Covance Laboratories Inc. |
Michael S.,Covance Laboratories Inc.
Bioanalysis | Year: 2011
The advancement of biotechnology has led to an increase in biotherapeutic drugs, especially recombinant proteins and monoclonal antibodies. Ligand-binding assays or immunoassays are the standard methods of choice in pharmacokinetic studies in support of drug discovery and development for protein therapeutics. LC-MS-based methodologies are increasingly used as alternatives to immunoassays for absolute protein quantitation in biological samples. We review recent advancements in absolute quantitation of protein therapeutics in biological matrices by enzymatic digestion and LC-MS. © 2011 Future Science Ltd.
Mastovska K.,Covance Laboratories Inc.
Methods in Molecular Biology | Year: 2011
Antibiotics are the most important drugs administered in veterinary medicine. Their use in food-producing animals may result in antibiotic residues in edible tissues, which are monitored to protect human and animal health, support the enforcement of regulations, provide toxicological assessment data, and resolve international trade issues. This chapter provides basic characterization of the most important classes of antibiotics used in food-producing animals (aminoglycosides, amphenicols, β-lactams, macrolides and lincosamides, nitrofurans, quinolones, sulfonamides, and tetracyclines), along with examples of practical liquid chromatographic-(tandem) mass spectrometric methods for analysis of their residues in food matrices of animal origin. The focus is on multiresidue methods that are favored by regulatory and other food testing laboratories for their ability to analyze residues of multiple compounds in a time- and cost-effective way. © 2011 Springer Science+Business Media, LLC.
Sullivan D.,Covance Laboratories Inc. |
Zywicki R.,Covance Laboratories Inc.
Journal of AOAC International | Year: 2012
A method was developed and validated for the determination of total iodine in a wide variety of food products and dietary supplements. The method involves a unique sample digestion with a KOH solution in an oven or by using an open-vessel microwave system. After digestion, a stabilizer is added and the solution is taken to volume, then filtered and analyzed either directly or after dilution. The amount of iodine is determined with inductively coupled plasma-mass spectrometry (ICP-MS). The method was validated by experiments to determine its precision, accuracy, linearity, specificity, ruggedness, and robustness. The LOQ of this method is 25-50 μg/kg. The method demonstrated an average RSD of 2.27% during analysis of milk powder and 4.30% during analysis of a dietary supplement tablet reference material. The accuracy of the method as determined with these same reference materials was 100 and 94.2%, respectively. The method has been used successfully on commodity foods, processed foods, dairy products, pet food, infant formula, animal feed, mineral premixes, and a variety of dietary supplements. © 2012 Publishing Technology.
Huang M.,Covance Laboratories Inc. |
Winters D.,Covance Laboratories Inc.
Journal of AOAC International | Year: 2011
Ultra-performance liquid chromatography (UPLC)/MS/MS was applied to measure vitamin D in various foods and nutritional supplements. The run-time of the chromatographic separation was cut from20min in HPLC/MS/MS to 10min in UPLC/MS/MS, while equal or better separation efficiency was achieved to deal with complex food matrixes. Under the optimized conditions, all the previtamins of vitamin D3, D2, and isotope-labeled vitamin D3 were baseline-separated from their corresponding vitamins. It was also demonstrated that many sterol isomers in complex food matrixes that interfere in the analysis could be well-separated from the analytes. Accuracy of this method was evaluated by analysis of NIST SRM 1849 infant formula reference material. With eight replicates, the average vitamin D3 concentration was 0.251 × 0.012 mg/kg, an excellent agreement with the certified value of 0.251 ± 0.027 mg/kg. In addition, spike recovery from a commercial infant formula matrix was in the range of 100 to 108% for both vitamins D3 and D2 at three spike concentration levels. The spike recovery for an even more complex matrix, pet food, was 101-105%. LOQ values were 0.026 and 0.033 IU/g, or 0.086 and 0.11 IU/mL in solution, for vitamins D3 and D2, respectively. The dynamic range had three orders of magnitude, which made the method flexible and useful to deal with the wide concentration range of vitamin D in various samples. The method was robust based on the results of changing the parameters of LC separation and MS measurement. This accurate and reliable vitamin D method increased instrument efficiency and analysis productivity significantly.