PubMed Health⌕ Search

Biomedical subjects

Wendy Nelson

Publications and source records attributed to Wendy Nelson.

8 recordsLinked to original sources

The adult human heart as a source for stem cells: repair strategies with embryonic-like progenitor cells.

Adequate cell-based repair of adult myocardium remains an elusive goal because most cells that are used cannot generate mature myocardium sufficient to promote large functional improvements. Embryonic stem cells can generate both mature cardiocytes and vasculature, but their use is hampered by associated teratoma formation and the need for an allogeneic source. The detection of sca-1(+), c-kit(+), or isl-1(+) cardiac precursors and the creation of cardiospheres from adult heart tissues suggest that a persistent population of immature progenitor cells is present in the mature myocardium. These cell populations probably represent stages along a continuum of cardiac stem cell development and differentiation. We report isolation from ventricle of uncommitted cardiac progenitor cells, which appear to resemble the more immature, common pool of embryonic lateral plate mesoderm progenitors that yield both myocardial and endocardial cells during normal cardiac development. Under controlled in vitro conditions and in vivo, these cells can differentiate into endothelial, smooth muscle, and cardiomyocyte lineages and can be isolated and expanded to clinically relevant numbers from adult rat myocardial tissue. In this article, we discuss the potential for autologous repair or even cardiac regeneration with cells that follow a developmental pathway similar to embryonic cardiac precursors but without the inherent limitations associated with undifferentiated embryonic stem cells.

Adult↗

Associations of perceived risk and worry with cancer health-protective actions: data from the Health Information National Trends Survey (HINTS).

This study examined the associations of susceptibility, conceptualized as both a cognition (risk) and as affect (worry) and their possible interaction, with cancer screening behaviors. Data for this study were obtained from the 2003 Health Information National Trends Survey (HINTS). Hierarchical regression models assessed the ability of risk, worry and their interaction (after controlling for other important variables) to predict cancer-screening behaviors. Results found that risk and worry (but not their interaction) were associated with regular mammography screening and having had a sigmoidoscopy or colonoscopy but with neither FOBT nor PSA screening. The findings suggest that risk and worry are both important in predicting some types of screening behavior and that these variables operate independently.

Female↗

A heuristics approach to understanding cancer risk perception: contributions from judgment and decision-making research.

BACKGROUND: The likelihood judgments that people make about their risks for cancer have important implications. At the individual level, risk estimates guide protective actions, such as cancer screening. However, at the extremes, exaggerated risk judgments can also lead to anxiety that degrades quality of life or to aggressive self-protective actions that are unwarranted given the objective risks. At the policy level, risk judgments may serve as an indicator of societal perceptions of the "war" against cancer. Using risk judgments, the public expresses its belief about whether we are winning. PURPOSE: We present theoretical perspectives from judgment and decision making, illustrate how they can explain some of the existing empirical findings in the cancer risk literature, and describe additional predictions that have not yet been tested. CONCLUSIONS: Overall, we suggest that theories from the judgment and decision-making perspective offer a potentially powerful view for understanding and improving risk judgments for cancer and other diseases.

Attitude to Health↗

Linking decision-making research and cancer prevention and control: important themes.

This article describes 6 themes underlying the multiple presentations from the Basic and Applied Decision Making in Cancer Control meeting, held February 19-20, 2004. The following themes have important implications for research and practice linking basic decision-making research to cancer prevention and control: (a) Traditional decision-making theories fail to capture real-world decision making, (b) decision makers are often unable to predict future preferences, (c) preferences are often constructed on the spot and thus are influenced by situational cues, (d) decision makers often rely on feelings rather than beliefs when making a decision, (e) the perspective of the decision maker is critical in determining preferences, and (f) informed decision making may--or may not--yield the best decisions.

Congresses as Topic↗

Basic and applied decision making in cancer control.

Decision making is fundamental to all aspects of cancer care--prevention, detection, treatment, survivorship, and end of life--yet researchers and clinicians have limited knowledge of the ways in which patients and their health care providers make critical health decisions. Recognizing how important it is to understand how patients and their providers make potentially life-altering decisions, the National Cancer Institute developed a decision making in cancer control initiative. The goal of this initiative is to enhance understanding of human decision-making processes so that individuals can make more informed and satisfying choices regarding their health. This article describes the multidisciplinary meeting that provided the scientific foundation for this initiative.

Decision Support Techniques↗

S-adenosylmethionine (AdoMet) modulates endotoxin stimulated interleukin-10 production in monocytes.

IL-10 is produced by a large variety of cells including monocytes, macrophages, B and T lymphocytes, as well as natural killer cells and is an important suppressor for both immunoproliferative and inflammatory responses. IL-10 exerts antifibrotic effects in the liver, and decreased monocyte synthesis of IL-10 is well documented in alcoholic cirrhosis. Intracellular deficiency of S-adenosylmethionine (AdoMet) is a hallmark of toxin-induced liver injury. Although the administration of exogenous AdoMet attenuates this injury, the mechanisms of its actions are not fully established. This study was performed to investigate the effect of exogenous AdoMet on IL-10 production in LPS-stimulated RAW 264.7 cells, a murine macrophage cell line. Our results demonstrated that exogenous AdoMet administration enhanced both protein production and gene expression of IL-10 in RAW 264.7 cells. Ethionine, an inhibitor for methionine adenosyltransferases, inhibited LPS-stimulated IL-10 both at the protein and mRNA levels. Exogenous AdoMet increased the intracellular cAMP concentration as early as 3 h and continued for 24 h after AdoMet treatment; however, the inhibitors for both adenylyl cyclase and PKA did not significantly affect IL-10 production. On the basis of these results, we conclude that AdoMet administration may exert its anti-inflammatory and hepatoprotective effects, at least in part, by enhancing LPS-stimulated IL-10 production.

Animals↗

Molecular dynamics simulation of site-directed spin labeling: experimental validation in muscle fibers.

We have developed a computational molecular dynamics technique to simulate the motions of spin labels bound to the regulatory domain of scallop myosin. These calculations were then directly compared with site-directed spin labeling experimental results obtained by preparing seven single-cysteine mutants of the smooth muscle (chicken gizzard) myosin regulatory light chain and performing electron paramagnetic resonance experiments on these spin-labeled regulatory light chains in functional scallop muscle fibers. We determined molecular dynamics simulation conditions necessary for obtaining a convergent orientational trajectory of the spin label, and from these trajectories we then calculated correlation times, orientational distributions, and order parameters. Simulated order parameters closely match those determined experimentally, validating our molecular dynamics modeling technique, and demonstrating our ability to predict preferred sites for labeling by computer simulation. In several cases, more than one rotational mode was observed within the 14-ns trajectory, suggesting that the spin label samples several local energy minima. This study uses molecular dynamics simulations of an experimental system to explore and enhance the site-directed spin labeling technique.

Animals↗