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Biomedical subjects

G S Omenn

Publications and source records attributed to G S Omenn.

At least 19 recordsLinked to original sources
PubMed2001

Assessment of human cancer risk: challenges for alternative approaches.

The ILSI/HESI Workshop on Alternatives to Carcinogenicity Testing aims to develop and apply new methods for assessment of potential carcinogenic risk to humans from various chemicals. The Workshop represents a major cooperative scientific effort. The long-term goals should be to greatly enhance the efficiency and reliability of such testing and to supplant, not just supplement, lifetime rodent bioassays. There are now well-established frameworks for risk assessment and risk management, putting risks into public health context and engaging stakeholders. The Lave-Omenn value-of-information model provides a useful way to assess the social costs and benefits of different strategies for testing large numbers of chemicals.

Academies and Institutes↗
PubMed2001

The new millennium: values, perceptions of risk, and the key roles of science and technology.

Radiation protection and management of radioactive waste streams and products are certain to be important areas of public policy, worker education, and technology development in the new millennium. Overriding values of freedom, sustainability, transparency, and public participation in decision making about technology's benefits and risks will shape the public policy agenda. Early engagement of stakeholders in the identification and assessment of risks and in communications about risk management will be beneficial in most cases. Putting specific environmental problems into broader public health and ecologic context will be helpful to all parties and will improve decisions about how best to utilize precious resources and enhance public confidence in the process and the outcomes.

Humans↗
PubMed2001

Prospects for pharmacogenetics and ecogenetics in the new millennium.

Genetics and genomics are certain to have a large impact in drug development and proper pharmaceutical treatment of subgroups of patients with many specific diseases. We should be able to increase the therapeutic margin for many agents. Genetic variation will also be important in refining estimates of risk from all kinds of environmental agents and in choosing more effective and more cost-effective risk reduction strategies. The linkage of information about genetic variation and information about environmental, nutritional, behavioral, metabolic, medical, and healthcare factors will be necessary to interpret the variation in clinical and public health terms. However, there is a great risk that present federal and state efforts to protect confidentiality and privacy of individual genetic information may make such research infeasible. In Michigan, a Governor's Commission has sought to strike an appropriate balance.

Genome↗
PubMed2001

Predictors of serum selenium in cigarette smokers and the lack of association with lung and prostate cancer risk.

Epidemiological studies have suggested that low levels of selenium are associated with a higher incidence of both lung and prostate cancer. We analyzed the selenium serum concentration in 356 Carotene and Retinol Efficacy Trial (CARET) participants who later developed lung cancer and 356 matched controls and in 235 prostate cancer cases and 456 matched controls. Serum samples were obtained a mean of 4.7 years before diagnosis for both tumor types. Controls were matched to cases by year of randomization, age, smoking status, treatment arm, exposure population (asbestos workers or cigarette smokers), and year of blood draw. In the control population (n = 820), significant predictors of low serum selenium concentration were current smoking status and East Coast locations of the study center. Overall, there was no significant difference in mean serum selenium in lung cancer cases versus controls (11.91 microg/dl versus 11.77 microg/dl) or prostate cancer cases versus controls (11.48 microg/dl versus 11.43 microg/dl). No statistically significant trend in odds ratio was seen across quartiles of serum selenium for lung cancer (P = 0.49) or prostate cancer (P = 0.69). In a subpopulation of 174 prostate cancer patients who had clinical and pathological staging material reviewed, there was no association between serum selenium and Gleason score or clinical or pathological stage. In the CARET population of current and former smokers consuming an ad libitum diet, the serum concentration of selenium was not a risk factor for either lung cancer or prostate cancer.

Age Distribution↗
PubMed2000

Risk estimation and value-of-information analysis for three proposed genetic screening programs for chronic beryllium disease prevention.

Genetic differences (polymorphisms) among members of a population are thought to influence susceptibility to various environmental exposures. In practice, however, this information is rarely incorporated into quantitative risk assessment and risk management. We describe an analytic framework for predicting the risk reduction and value-of-information (VOI) resulting from specific risk management applications of genetic biomarkers, and we apply the framework to the example of occupational chronic beryllium disease (CBD), an immune-mediated pulmonary granulomatous disease. One described Human Leukocyte Antigen gene variant, HLA-DP beta 1*0201, contains a substitution of glutamate for lysine at position 69 that appears to have high sensitivity (approximately 94%) but low specificity (approximately 70%) with respect to CBD among individuals occupationally exposed to respirable beryllium. The expected postintervention CBD prevalence rates for using the genetic variant (1) as a required job placement screen, (2) as a medical screen for semiannual in place of annual lymphocyte proliferation testing, or (3) as a voluntary job placement screen are 0.08%, 0.8%, and 0.6%, respectively, in a hypothetical cohort with 1% baseline CBD prevalence. VOI analysis is used to examine the reduction in total social cost, calculated as the net value of disease reduction and financial expenditures, expected for proposed CBD intervention programs based on the genetic susceptibility test. For the example cohort, the expected net VOI per beryllium worker for genetically based testing and intervention is $13,000, $1,800, and $5,100, respectively, based on a health valuation of $1.45 million per CBD case avoided. VOI results for alternative CBD evaluations are also presented. Despite large parameter uncertainty, probabilistic analysis predicts generally positive utility for each of the three evaluated programs when avoidance of a CBD case is valued at $1 million or higher. Although the utility of a proposed risk management program may be evaluated solely in terms of risk reduction and financial costs, decisions about genetic testing and program implementation must also consider serious social, legal, and ethical factors.

Berylliosis↗
PubMed2000

Public health genetics: an emerging interdisciplinary field for the post-genomic era.

Public health genetics is an exciting interdisciplinary area that brings all the public health sciences to bear on the emerging challenge of interpreting the medical and public health significance of genetic variation within populations. Sequencing of the human genome will generate an avalanche of genetic information to be linked with information about microbial, chemical, and physical exposures; nutrition, metabolism, lifestyle behaviors, and medications. The public health genetics mini-symposium in this volume includes articles dealing with educational innovations, host-pathogen interactions in infectious diseases, nutrition/genetic interactions in cancers, and population screening for hemochromatosis. Additional topics addressed here are ecogenetics and risk assessment, the genetics of unhealthful behaviors, and ethical and policy issues. Finally, a set of principles for community-based health research in populations is presented as a public health-oriented counterpart to the principle of autonomy and the practice of informed consent that have become key elements of ethics in medical care and medical research with individuals.

Ethics, Medical↗
PubMed1999

Predictors of participant retention in two chemoprevention feasibility trials.

Retention of participants for intervention and follow-up activities is critical in cancer chemoprevention trials. Little has been published about retention patterns and predictors of retention in prevention studies. The Carotene and Retinol Efficacy Trial (CARET) provides an opportunity to study retention of volunteer participants in a large, long-term clinical trial. Two pilot studies were conducted in different populations to test the feasibility of critical strategies for the long-term study. Thirteen percent of the asbestos-exposed workers and 18% of the smokers became inactive during the pilot study. Of those remaining active, all but 2% of asbestos-exposed workers pilot study participants and 5% of smokers pilot study participants chose to participate in the full-scale efficacy trial. Five baseline predictors of inactivity for the asbestos-exposed participants emerged: being non-White, being a current smoker, having a history of high blood pressure at baseline, reporting two or more increases in symptoms during the placebo run-in, and having higher baseline levels of negative mental health measures (i.e. anxiety, depression, and fatigue). The only significant predictor of inactivity for smoker pilot participants was reporting symptoms during the placebo run-in. The most frequently reported reasons for becoming inactive during the pilot studies were general health issues and problems and symptoms that were seen as specific to the CARET vitamins. These findings suggest areas that could be tested to optimize retention in clinical trials.

Aged↗
PubMed1999

Caring for the community: the role of partnerships.

While many members of the public are deeply interested in and supportive of the three traditional missions of academic medicine--education, research, and clinical care, they also want to know what academic health centers (AHCs) are doing to improve the overall health of their communities. Much is already being done toward this goal, but improving communities' health in a measurable way requires a far broader agenda. AHCs must bring together the approaches of medicine and public health, and need to partner with many other players. This agenda must proceed despite all the other challenges that AHCs are currently facing. The author reviews illustrative and emerging national, state, and local efforts, public and private, in both medicine and public health, in partnerships with individuals and institutions in the larger community. He also highlights the physician's role in assisting stakeholders' efforts to deal with health threats from the environment, and offers advice about how such efforts should proceed. He closes by emphasizing the importance of community-based research to learn about the health statuses, problems, and resources of particular communities, and presents a set of principles for such community-based research.

Academic Medical Centers↗