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Biomedical subjects

J Baron

Publications and source records attributed to J Baron.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

The skin: target organ in immunotoxicology of small-molecular-weight compounds.

Immunotoxicology studies two different effects of xenobiotics: immunosuppression and dysregulation of immune responses leading to hypersensitivity or autoimmunity. The skin is a major target organ of immunotoxicity which is provoked by small-molecular-weight compounds. Methods may be helpful for immunotoxicological investigations and screenings for adverse effects of xenobiotics which are used for diagnosis or studies on the pathophysiology of skin disorders such as allergic contact dermatitis, cutaneous drug-allergic reactions or autoimmune diseases of the skin. Examples include well-designed patch tests, assays involving antigen-presenting cells such as dendritic cells, but also T lymphocytes, basophiles or keratinocytes.

Animals↗
PubMedDate not supplied

Lymphocyte activation in allergic reactions elicited by small-molecular-weight compounds.

The involvement of cytochrome-P450-dependent metabolism of small-molecular-weight compounds as a prerequisite for an optimal lymphocyte response to those compounds is discussed on the basis of studies with compound such as p-phenylenediamine, sulfamethoxazole, chloramphenicol and fragrances. Subsequently, data on cytochrome P450 activity and CYP gene expression in monocytes and MAC-6 cells for cytochromes P450 2E1 and 3A4 are presented.

Chloramphenicol↗
PubMedDate not supplied

The inclusion of patient testimonials in decision aids: effects on treatment choices.

BACKGROUND: Decision aids often provide statistical information and patient testimonials to guide treatment choices. This raises the possibility that the testimonials will overwhelm the statistical information. METHODS: Prospective jurors in Philadelphia County were presented with hypothetical statistical information about the percentage of angina patients who benefit from angioplasty and bypass surgery (50% and 75%, respectively). They were also given written testimonials from hypothetical patients who had benefited or not benefited from each of the two treatments. The numbers of patients benefiting and not benefiting were varied to be either proportionate to the statistical information or disproportionate. In study 1, all participants received 1 testimonial from a patient who had benefited from angioplasty and 1 from a patient who had not. Participants receiving the proportionate questionnaire version were also given 3 testimonials from patients who benefited from bypass surgery and 1 from a patient who did not, coinciding with the hypothetical statistical information. In contrast, participants receiving the disproportionate questionnaire version received only 1 testimonial from a patient who benefited from surgery and 1 from a patient who did not. In study 2, all participants received 2 examples of patients who benefited from angioplasty and 2 who did not. Participants with the proportionate questionnaire version received the same testimonials regarding surgery as in study 1. Those receiving the disproportionate questionnaire version received 2 testimonials from patients who benefited from bypass and 2 from patients who did not. Finally, a separate set of participants in study 2 received a questionnaire with no testimonials. RESULTS: In study 1, 30% of participants receiving the disproportionate questionnaire version chose bypass surgery versus 44% of those receiving the proportionate questionnaire (P = 0.002 by chi2). In study 2, 34% of participants receiving the disproportionate questionnaire version chose bypass surgery versus 37% of those receiving the proportionate questionnaire (P = 0.59 by chi2). Of those receiving no patient testimonials, 58% chose bypass surgery. CONCLUSIONS: The inclusion of written patient testimonials significantly influenced hypothetical treatment choices. Efforts to make the mix of positive versus negative testimonials proportionate to statistical information may, under some circumstances, affect choices in ways that cannot automatically be assumed to be optimal.

Angina Pectoris↗
PubMedDate not supplied

Preference for equity as a framing effect.

BACKGROUND: In previous studies, the authors found that most people, given a fixed budget, would rather offer a less effective screening test to 100% of a Medicaid population than a more effective test to 50% of the population. In a subsequent study, the authors found that the number of people preferring the less effective screening test was dramatically reduced when the percentage of Medicaid enrollees receiving it was less than 100. In this article, 2 new studies are reported that explore whether people's preferences for equity versus efficiency are susceptible to a framing effect. METHODS: In 2 studies, the authors presented subjects with multiple scenarios involving screening tests that vary in the proportion of people who could receive the tests within a budget constraint and the number of people whose lives each test would save. Across scenarios, the proportion of Medicaid enrollees who could receive each test was varied, as was the question of whether scenarios involved Medicaid enrollees from the same or a different state. In addition, the authors varied the order in which subjects received the scenarios. RESULTS: In the 1st study, people's preferences for equity over efficiency varied significantly depending on the way situations were framed. Preference for equity was stronger when the more widely distributed choice covered the entire population than when it covered only half the population (P < 0.001). In addition, people's preferences were susceptible to order effects, with preference for equity being significantly stronger when the 1st scenario received by subjects involved 1 screening test that could be offered to the entire population (P < 0.001). In the 2nd study, preferences for equity over efficiency diminished even when the different framings were descriptions of identical circumstances--preference for equity was significantly reduced when the population to be screened was framed broadly, in terms of the percentage of patients across 2 states who could receive testing rather than narrowly, in terms of the percentages of patients in 1 state who could receive testing (P = 0.04). CONCLUSION: Policy planners should be careful about accepting public preferences for equity over efficiency at face value, because such preferences can be dramatically influenced by framing effects and order effects.

Adolescent↗
PubMedDate not supplied

Do nonpatients underestimate the quality of life associated with chronic health conditions because of a focusing illusion?

BACKGROUND: A number of studies show that the general public often estimates that the quality of life (QOL) associated with various health conditions is worse than patients say it is. These studies raise the possibility that people overestimate the impact that unfamiliar health conditions will have on their quality of life. One possible reason people overestimate this is because they are susceptible to a focusing illusion--when asked to imagine themselves in unfamiliar circumstances, people overestimate the emotional impact of those features of their life that would change. METHODS: The authors surveyed members of the general public to test the hypothesis that their QOL ratings of hypothetical health conditions would be higher (indicating a better quality of life) after thinking about how the health condition would affect a broad range of life domains. Across 3 experiments, the authors varied the health conditions people were asked to consider (either paraplegia, below-the-knee amputation, or partial blindness), the life domains they were asked to consider, the response mode with which they evaluated how each health condition would affect each life domain, whether subjects rated the health condition before and after considering life domains or only after, and whether subjects rated their own current quality of life first. RESULTS: Across 3 experiments, using 10 different questionnaire versions, only 1 instance was found in which subjects' ratings were significantly higher after thinking about the effect of the health condition on life domains than before, and the magnitude of this increase was small. CONCLUSION: It could not be established that a focusing illusion contributes significantly to the discrepancy in QOL ratings of patients and nonpatients. Further research should explore other factors that could contribute to the discrepancy or other ways of testing for the influence of a focusing illusion.

Adult↗
PubMedDate not supplied

Revising a priority list based on cost-effectiveness: the role of the prominence effect and distorted utility judgments.

BACKGROUND: People sometimes object to the results of cost-effectiveness analysis when the analysis produces a ranking of options based on both cost and benefit. We suggest 2 new reasons for these objections: the prominence effect, in which people attend mostly to a more prominent attrbute (benefit as opposed to cost), and distortion of utility judgments. METHOD: We simulated the production of a cost-effectiveness ranking list in 3 experiments using questionnaires on the World Wide Web. Subjects rated the utility of 16 health benefits using either rating scale or person trade-off elicitation methods. In some experiments, subjects were asked to rate the utility of the health benefits with attention also to the cost of achieving the benefits. In all experiments, at the end, subjects were shown a priority list based on their own utility judgments and were asked whether they wanted to move any of the health benefits up or down the list. RESULTS: In all experiments, subjects wanted to give higher priority to treatments with higher benefit, even when they also had higher cost. They thus wanted to give less weight to high cost (which would, by itself, lead to lower ranking) and more weight to benefit than the weight implied by their own prior judgments. The desire for revision was reduced when subjects made their utility judgments after indicating whether the utility was above or below the midpoint of the scale (a manipulation previously found to reduce distortion). CONCLUSION: The desire to change cost-effectiveness rankings is in part a preference reversal phenomenon that occurs because people attend mainly to the benefit of health interventions as opposed to cost, when they examine the ranking. People should be wary of tinkering with priority lists by examining the lists themselves.

Adolescent↗
PubMedDate not supplied

Clinical reasoning and cognitive processes.

Expected utility theory, and the Bayesian probability theory on which it is based, form the normative basis of most work in medical decision analysis. Recent work in the psychology of judgments and decisions indicates that people do not conform to the axioms of this theory and that these deviations occur in clinical reasoning as well as in the psychology laboratory. At issue is what to do now. The authors argue that the important next steps lie at the interface between descriptive, prescriptive, and normative accounts, all of which affect each other. They point to examples in which the simplest application of supposedly normative theory seems inappropriate, and suggest ways in which the tension between normative and descriptive models may be resolved.

Cognition↗
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Omission bias and pertussis vaccination.

BACKGROUND: Several laboratory studies have suggested that many people favor potentially harmful omissions over less harmful acts. The authors studied the role of this omission bias in parents' decisions whether to vaccinate their children against pertussis. METHODS: Two hundred mail surveys were sent to subscribers to a magazine that had published articles favoring and opposing pertussis vaccination. Subjects were asked about their beliefs about the vaccine and the disease, and whether they had vaccinated their own children or planned to, and they were given test items to identify omission bias in their reasoning. RESULTS: One hundred and three subjects (52%) responded to the survey. Respondents who reported they did not or would not allow their children to be vaccinated (n = 43; 41%) were more likely to believe that vaccinating was more dangerous than not vaccinating (p < 0.001). They were also more likely to exhibit omission bias (p = 0.004), holding constant their stated beliefs about the danger of the vaccine. CONCLUSIONS: Omission bias plays a role in decisions not to vaccinate with pertussis vaccine, beyond the role played by belief about the risk of vaccination.

Adult↗
PubMedDate not supplied

Attitudes of obstetricians and gynecologists toward hormone replacement therapy.

OBJECTIVE: To determine the attitudes of obstetricians and gynecologists toward hormone replacement therapy (HRT), and the beliefs and intuitions that affected those attitudes. DESIGN: A questionnaire was sent to 1,000 gynecologists in the United States; 328 replies were received. The questionnaire asked about effects of HRT, practices concerning HRT, and decisions in hypothetical scenarios. RESULTS: The respondents strongly favored HRT, and they were well informed about its effects on osteoporosis, cardiovascular disease, and breast cancer. They were aware of conflicting findings concerning breast cancer. The strength of their recommendation of HRT was sensitive to patient differences in risk factors. The respondents also showed four biases hypothesized to cause resistance to HRT: omission bias (more concern about harmful acts than harmful omissions); proportionality bias (attention to relative risk rather than risk differences); naturalness bias (preference for the natural); and ambiguity (avoiding options with missing information). Proportion bias, naturalness bias, and (weakly) omission bias were related to less favorable attitudes toward HRT. CONCLUSION: Although specialists are highly favorable toward HRT in general, some negativity toward HRT may result from decision biases.

Adult↗
PubMedDate not supplied

[Pineal cyst in MRI: clinical symptoms and analysis].

Application of magnetic resonance imaging (MRI) in radiology allows to estimate and analyse pineal gland and pineal region pathology more precisely. We report 47 MRI brain studies of patients in whom pineal cyst was recognized as the only pathologic finding. MRI of the brain was performed because of clinical symptoms as headaches (32%), vertigo (26%) and altered behaviour (13%). Because of the common occurrence of pineal cyst in MRI brain imaging it seems to be important to decide whether these patients need neurosurgical intervention, especially if together with morphologic abnormality definite clinical symptoms exist.

Adolescent↗