The E. Donnall Thomas Lecture: Normal and Neoplastic Stem Cells

AbstractDr. Irving Weissman was the honored E. Donnall Thomas lecturer at the Tandem BMT Meetings, held on February 10, 2007, at Keystone, Colorado. Dr. Weissman has been a major player, and has provided us with enormous insight into many areas of biology, dating back to his high school days in Montana. He led an enormously productive career at Stanford University where he has taught us many lessons involving our understanding of lymphocyte homing, stem cell biology, both of the hematopoietic system and other types of stem cells, and also now, about cancer stem cells. Dr. Weissman has made enormous contributions to this burgeoning field that has provided us new insights and new opportunities for treatment strategies. In addition to a very productive laboratory career, he is also currently the director of both the Stem Cell Institute, as well as the Cancer Center at Stanford University. The following text is a modified transcribed version of the presentation made by Dr. Weissman

WHERE DOES NEWS ABOUT PRESCRIPTION DRUGS COME FROM?: EXPLORING HOW ORGANIZATIONS BUILT AND FRAMED THE NATIONAL NEWS MEDIA AGENDA FOR HORMONE THERAPY FROM 1995 TO 2011

ABSTRACT This longitudinal study explored how health and medical organizations used public relations techniques to influence news content about postmenopausal hormone therapy (HT) from 1995 to 2011. A theoretical framework that combined agenda building, information subsidies, and framing guided the study (Zoch & Molleda, 2006). Quantitative content analyses were conducted on 675 press releases about HT distributed through PR Newswire and EurekAlert!, and 429 news stories about HT in the Associated Press Newswire (AP), The New York Times, The Washington Post, Los Angeles Times, and The Wall Street Journal. Supplemental qualitative content analyses of organizational websites, annual reports, and scientific publications explored financial relationships and potential collaborations between ten organizations that emerged as the most successful agenda builders. Six types of health and medical organizations produced press releases about HT: pharmaceutical companies, academic/medical institutions, nonprofit health advocacy organizations, medical/scientific journal publishers, U.S. government agencies, and other for-profit organizations. A positive, statistically significant relationship was found between the quantity of press releases and news stories over time (r = .55, p<.001). Findings also supported the transference of specific objects, such as brand-name HT products, and attributes, such as risks and benefits, from the public relations to the news media agenda. Academic/medical institutions and nonprofit health advocacy organizations were significantly more likely than pharmaceutical companies to identify non-FDA approved, "off-label" benefits. Wyeth Pharmaceuticals, manufacturer of leading HT brands Premarin and Prempro, financially subsidized most of the top-ten, agenda-building organizations, including four academic/medical institutions and two non-profit health advocacy organizations that were frequently cited in news stories. Additionally, a substantial degree of synergy was found between these organizations in terms of how they framed menopause and HT over the study period. This study supported and extended the theoretical framework used by offering insights into how organizations may collaborate through funding arrangements and third-party communication techniques to influence news content in a health and medical context. The findings also contributed a new and important dimension to scholarship on pharmaceutical promotion of prescription drugs, which has neglected the role of public relations and focused almost exclusively on more overt, paid-promotional efforts like direct-to-consumer advertising

Food Security in the 21\u3csup\u3est\u3c/sup\u3e Century: Lessons from Cuban Agriculture for Materializing Realities

Worldwide, hunger continues to pose great problems for humanity. Despite popular belief, hunger is a problem of inequality, not agricultural production. The fast-approaching global peak in oil production, the point at which half of all existing oil has been used, means that hunger, now a problem of inequality, will soon become a problem of production unless contemporary agricultural production is transformed. This project examines the promise of urban agriculture in providing food security following the collapse of petroagriculture. The case of Cuba, albeit fostered by political economic conditions and not emerging geophysical limitations, provides a model of agricultural development for the rest of the world. The collapse of the Soviet trade bloc in 1989 undermined Cuba’s agriculture sector, as former inputs (particularly petroleum) were no longer available. To feed its population, Cuba initiated the largest organic agriculture effort in history. In doing so, Cuba successfully thwarted potentially devastating hunger and possible famine. Degradation of the planet is inextricably linked to the degrading conditions of life for the majority of the world’s population. A systematic examination of the Cuban case exemplifies the importance and feasibility of urban agriculture for simultaneously addressing the roots of both

Two-step phase changes in cubic relaxor ferroelectrics

The field-driven conversion between the zero-field-cooled frozen relaxor state and a ferroelectric state of several cubic relaxors is found to occur in at least two distinct steps, after a period of creep, as a function of time. The relaxation of this state back to a relaxor state under warming in zero field also occurs via two or more sharp steps, in contrast to a one-step relaxation of the ferroelectric state formed by field-cooling. An intermediate state can be trapped by interrupting the polarization. Giant pyroelectric noise appears in some of the non-equilibrium regimes. It is suggested that two coupled types of order, one ferroelectric and the other glassy, may be required to account for these data.Comment: 27 pages with 8 figures to appear in Phys. Rev.

Endogenous Wnt signalling in human embryonic stem cells generates an equilibrium of distinct lineage-specified progenitors.

The pluripotent nature of human embryonic stem cells (hESCs) makes them convenient for deriving therapeutically relevant cells. Here we show using Wnt reporter hESC lines that the cells are heterogeneous with respect to endogenous Wnt signalling activity. Moreover, the level of Wnt signalling activity in individual cells correlates with differences in clonogenic potential and lineage-specific differentiation propensity. The addition of Wnt protein or, conversely, a small-molecule Wnt inhibitor (IWP2) reduces heterogeneity, allowing stable expansion of Wnt(high) or Wnt(low) hESC populations, respectively. On differentiation, the Wnt(high) hESCs predominantly form endodermal and cardiac cells, whereas the Wnt(low) hESCs generate primarily neuroectodermal cells. Thus, heterogeneity with respect to endogenous Wnt signalling underlies much of the inefficiency in directing hESCs towards specific cell types. The relatively uniform differentiation potential of the Wnt(high) and Wnt(low) hESCs leads to faster and more efficient derivation of targeted cell types from these populations

Aging in the Relaxor Ferroelectric PMN/PT

The relaxor ferroelectric (PbMn$_{1/3}$Nb$_{2/3}$O$_3$)$_{1-x}$(PbTiO$_3$)$_{x}$, $x=0.1$, (PMN/PT(90/10)) is found to exhibit several regimes of complicated aging behavior. Just below the susceptibility peak there is a regime exhibiting rejuvenation but little memory. At lower temperature, there is a regime with mainly cumulative aging, expected for simple domain-growth. At still lower temperature, there is a regime with both rejuvenation and memory, reminiscent of spin glasses. PMN/PT (88/12) is also found to exhibit some of these aging regimes. This qualitative aging behavior is reminiscent of that seen in reentrant ferromagnets, which exhibit a crossover from a domain-growth ferromagnetic regime into a reentrant spin glass regime at lower temperatures. These striking parallels suggest a picture of competition in PMN/PT (90/10) between ferroelectric correlations formed in the domain-growth regime with glassy correlations formed in the spin glass regime. PMN/PT (90/10) is also found to exhibit frequency-aging time scaling of the time-dependent part of the out-of-phase susceptibility for temperatures 260 K and below. The stability of aging effects to thermal cycles and field perturbations is also reported.Comment: 8 pages RevTeX4, 11 figures; submitted to Phys. Rev.

A Titan exploration study: Science, technology, and mission planning options, volume 2

For abstract, see Vol.