LLNL researchers identify how many cancer cells it takes to initiate metastatic tumors
For the first time, researchers have developed a way to determine how many cancer cells it takes to initiate a tumor in another part of the body. The findings, made by a team of LLNL scientists, are published in the journal Scientific Reports. The Livermore scientists have been studying how cancer spreads through the body, using the Lab’s AMS technology and mouse models with cancer, for the past three years through a grant from the National Institutes of Health.
Big results come from small instrument
A new kid is coming to town in the form of an ultra-sensitive, laser-based, carbon-14 spectrometer that will be able to measure samples as small as one microgram of carbon. LLNL engineer Daniel McCartt has built laser-based detection methods for rare isotopes to supplement the Lab’s AMS detection capabilities. The new laser-based, rare-isotope detection technique would combine with biochemistry tools like liquid chromatography.
Biomedical Technology Accelerates into ‘Science on Saturday’ Program
LLNL’s educational outreach program Science on Saturday returned in February for a season of Marvelous Machines . In a February 10 presentation titled “Biomedical Accelerator Mass Spectrometry: Improving Human Health One Atom at a Time,” LLNL biomedical scientist Mike Malfatti and Dougherty Valley High School (DVHS; San Ramon, CA) teacher Katherine Huang teamed up to explain how accelerator mass spectrometry (AMS) helps advance bioscience.
Bruce Buchholz presents during NIEHS SRP webinar
Bruce Buchholz presented “Metabolite quantitation and biomarker development using accelerator mass spectrometry” during the National Institute of Environmental Health Sciences (NIEHS) Superfund Research Program (SRP) Risk e-Learning Analytical Tools and Methods webinar on May 22, 2017. The webinar was Session II in the series and focused on Techniques for Trace Analysis of Metals and Chemical Mixtures. Buchholz described how Accelerator Mass Spectrometry (AMS) is used to measure zeptomole to femtomole quantities of carbon-14 in sub milligram sized samples. He described applications used to quantify metabolism of chemicals at relevant exposures in animals and humans, such as dermal exposure to pesticides and ingestion of PAHs or antimicrobials. The metabolism studies have become more streamlined recently with the addition of an integrated HPLC-AMS-MS system and can identify dominant metabolites at relevant doses from which specific field assays can be developed without the use of the carbon-14 label. All tissues, blood, urine, saliva, or purified biomolecules (protein, DNA, RNA) are amenable to AMS analyses. The session has been recorded and is accessible to the public for viewing on the Hazardous Waste Clean-Up Information website.
Personalized cancer medications
Biomedical scientists at the Lawrence Livermore National Laboratory are teaming up with medical oncologists at UC Davis to see if they can find out within minutes how someone will respond to certain therapeutic drugs, including chemotherapy. In this full-length interview by UC Science Today, learn how biomedical AMS is making this possible.
LLNL BioAMS article makes editor’s list for Editorial Board of Chemical Research in Toxicology
Every year at the fall ACS meeting, the Editorial Board of Chemical Research in Toxicology (CRT) meets to enjoy a social hour and dinner. At the 2015 meeting in Boston, the Editorial Advisory Board members were asked to pick their favorite paper published in CRT in the past two years; these would be collected in a virtual issue. Sixteen papers were highlighted and chosen. The following paper was one of the sixteen chosen:
Madeen, E., Corley, R.A., Crowell, S., Turteltaub, K., Ognibene, T., Malfatti, M., McQuistan, T.J., Garrard, M., Sudakin, D., and Williams, D.E. (2015), Human in Vivo Pharmacokinetics of [14C]Dibenzo[def,p]chrysene by Accelerator Mass Spectrometry Following Oral Microdosing, Chem. Res. Toxicol. 28 (1), 126, doi: 10.1021/tx500.
Bruce Buchholz discusses radiocarbon bomb pulse dating
Research Resource scientist Bruce Buchholz appeared with collaborators Kirsty Spalding and Jonas Frisén of the Karolinska Institute in Stockholm, Sweden on the episode “Elements” of the National Public Radio program Radiolab. In a segment on the element carbon, the trio discussed how they developed radiocarbon bomb pulse dating to determine the age of cells in the human body. The program was broadcast in August 2015.
Chemotherapy helps save the lives of thousands of cancer patients each year. But now, researchers at the Lawrence Livermore National Laboratory (LLNL) and UC Davis believe they’ve developed a technology that could make chemo treatments even more effective. Channel 7 (KGO-TV, San Francisco) aired this story about the LLNL-UC Davis cancer collaboration.
LLNL Scientists’ paper published in Analytical Chemistry highlights the use of Liquid sample AMS
“Directly Coupled High-Performance Liquid Chromatography–Accelerator Mass Spectrometry Measurement of Chemically Modified Protein and Peptides” Avi T. Thomas, Benjamin J. Stewart, Ted J. Ognibene, Kenneth W. Turteltaub, and Graham Bench.
Quantitation of low-abundance protein modifications involves significant analytical challenges, especially in biologically important applications, such as studying the role of post-translational modifications in biology and measurement of the effects of reactive drug metabolites. 14C labeling combined with accelerator mass spectrometry (AMS) provides exquisite sensitivity for such experiments. Here, we demonstrate real-time 14C quantitation of high-performance liquid chromatography (HPLC) separations by liquid sample accelerator mass spectrometry (LS-AMS). By enabling direct HPLC-AMS coupling, LS-AMS overcomes several major limitations of conventional HPLC-AMS, where individual HPLC fractions must be collected and converted to graphite before measurement.
Collaboration with Swedish scientists uses bomb pulse 14C to reveal dynamics of human hippocampal neurogenesis
“Dynamics of Hippocampal Neurogenesis in Adult Humans” Kirsty L. Spalding, Olaf Bergmann, Kanar Alkass, Samuel Bernard, Mehran Salehpour, Hagen B. Huttner, Emil Boström, Isabelle Westerlund, Céline Vial, Bruce A. Buchholz, Göran Possnert, Deborah C. Mash, Henrik Druid, Jonas Frisén.
Adult-born hippocampal neurons are important for cognitive plasticity in rodents. There is evidence for hippocampal neurogenesis in adult humans, although whether its extent is sufficient to have functional significance has been questioned. The generation of hippocampal cells in humans has been determined by measuring the concentration of nuclear-bomb-test-derived 14C in genomic DNA. It was found that a large subpopulation of hippocampal neurons constituting one-third of the neurons is subject to exchange. In adult humans, 700 new neurons are added in each hippocampus per day, corresponding to an annual turnover of 1.75% of the neurons within the renewing fraction, with a modest decline during aging. It appears that neurons are generated throughout adulthood and that the rates are comparable in middle-aged humans and mice, suggesting that adult hippocampal neurogenesis may contribute to human brain function.