Huber R. Warner

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMicrodetermination of PhosphorusP. S. Chen, T. Y. Toribara, and Huber. WarnerCite this: Anal. Chem. 1956, 28, 11, 1756–1758Publication Date (Print):November 1, 1956Publication History Published online1 May 2002Published inissue 1 November 1956https://pubs.acs.org/doi/10.1021/ac60119a033https://doi.org/10.1021/ac60119a033research-articleACS PublicationsRequest reuse permissionsArticle Views6581Altmetric-Citations5821LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

The National Institute on Aging's Interventions Testing Program was established to evaluate agents that are purported to increase lifespan and delay the appearance of age-related disease in genetically heterogeneous mice. Up to five compounds are added to the study each year and each compound is tested at three test sites (The Jackson Laboratory, University of Michigan, and University of Texas Health Science Center at San Antonio). Mice in the first cohort were exposed to one of four agents: aspirin, nitroflurbiprofen, 4-OH-alpha-phenyl-N-tert-butyl nitrone, or nordihydroguaiaretic acid (NDGA). Sample size was sufficient to detect a 10% difference in lifespan in either sex,with 80% power, using data from two of the three sites. Pooling data from all three sites, a log-rank test showed that both NDGA (p=0.0006) and aspirin (p=0.01) led to increased lifespan of male mice. Comparison of the proportion of live mice at the age of 90% mortality was used as a surrogate for measurement of maximum lifespan;neither NDGA (p=0.12) nor aspirin (p=0.16) had a significant effect in this test. Measures of blood levels of NDGA or aspirin and its salicylic acid metabolite suggest that the observed lack of effects of NDGA or aspirin on life span in females could be related to gender differences in drug disposition or metabolism. Further studies are warranted to find whether NDGA or aspirin, over a range of doses,might prove to postpone death and various age-related outcomes reproducibly in mice.

These proceedings contain 30 papers grouped under the headings of: Theories of aging: A perspective; Evolution of life span in placental mammals; Developmentally programmed aging; Free-radical damage; Error catastrophe; DNA Damage and repair; and Organ systems as pacemakers of aging.

The National Institute on Aging's Interventions Testing Program (ITP) has developed a plan to evaluate agents that are considered plausible candidates for delaying rates of aging. Key features include: (i) use of genetically heterogeneous mice (a standardized four-way cross), (ii) replication at three test sites (the Jackson Laboratory, TJL; University of Michigan, UM; and University of Texas, UT), (iii) sufficient statistical power to detect 10% changes in lifespan, (iv) tests for age-dependent changes in T cell subsets and physical activity, and (v) an annual solicitation for collaborators who wish to suggest new interventions for evaluation. Mice in the first cohort were exposed to one of four agents: aspirin, nitroflurbiprofen (NFP), 4-OH-alpha-phenyl-N-tert-butyl nitrone (4-OH-PBN), or nordihydroguiaretic acid (NDGA). An interim analysis was conducted using survival data available on the date at which at least 50% of the male control mice had died at each test site. Survival of control males was significantly higher, at the interim time-point, at UM than at UT or TJL; all three sites had similar survival of control females. Males in the NDGA group had significantly improved survival (P = 0.0004), with significant effects noted at TJL (P < 0.01) and UT (P < 0.04). None of the other agents altered survival, although there was a suggestion (P = 0.07) of a beneficial effect of aspirin in males. More data will be needed to determine if any of these compounds can extend maximal lifespan, but the current data show that NDGA reduces early life mortality risks in genetically heterogeneous mice at multiple test sites.