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Biomedical subjects

J C Fletcher

Publications and source records attributed to J C Fletcher.

At least 55 records · Page 3Linked to original sources
PubMed1993

Molecular analysis of the initiation of insect metamorphosis: a comparative study of Drosophila ecdysteroid-regulated transcription.

More than 50 ecdysteroid-regulated Drosophila genes have been described in the literature. These genes were identified using several different ecdysteroid-responsive systems and characterized under a variety of experimental conditions. The diversity of these approaches has made it difficult to compare results and identify common responses to the hormone. As a first step toward characterizing the temporal regulation of these genes by ecdysteroids, we have examined their transcriptional activity throughout third instar larval and prepupal development using a single collection of staged animals. We see four coordinate changes in ecdysteroid-regulated gene activity during third instar larval development, at 78-88 hr, approximately 100 hr, 106-108 hr, and approximately 114 hr after egg laying. A dramatic transition in gene expression occurs at puparium formation, after which the prepupal ecdysteroid pulse induces successive waves of transcription. Our results suggest that several increases in the ecdysteroid titer during third instar larval and prepupal development program a precise temporal progression of gene activity that could direct the appropriate behavioral and developmental changes at the onset of metamorphosis.

Animals↗
PubMed1993

HECs: are they evaluating their performance?

Although the incidence and composition of HECs has been well characterized, little is known about how HECs assess their performance. In order to describe the incidence of HEC self-evaluation, the methods HECs use to evaluate their performance, and the characteristics of HECs that influence self-evaluation, we surveyed the readers of Hospital Ethics. 290 HECs in 45 U.S. states, the District of Columbia, Puerto Rico and three Canadian provinces, completed questionnaires. Of the 241 HECs included in the data analysis, 97.9% had performed some self-evaluation. Responding committees largely made formative rather than summative evaluations and appeared to evaluate performance in light of their own objectives rather than basing assessments on specific structural, process, and outcome measures of quality. Responding committees used certain evaluation criteria more extensively than others--among these, the number of participants and staff knowledge of the service provided--with the choice of criteria differing with the function being evaluated. Eight characteristics of HECs influenced the probability of self-evaluation, including age, number of beds and meetings, the existence of a mission statement, and a budget. The presence of certain characteristics made HECs six times more likely to evaluate their performance than HECs without the characteristic.

Canada↗
PubMed1993

Prenatal diagnosis and sex selection in 19 nations.

As part of a study of ethics and human genetics in 19 nations, we surveyed attitudes of 71 medical geneticists in 4 developing nations (Brazil, Greece, India and Turkey), and 611 geneticists in 15 developed nations, using anonymous questionnaires. Overall, 52% in India, 30% in Brazil, 29% in Greece, and 20% in Turkey would perform prenatal diagnosis to select a male fetus for a couple with 4 daughters and no sons. Sex selection is the major use of prenatal diagnosis in India. The majority in the U.S.A. (62%) and Hungary (60%) would also do sex selection or refer. We discuss possible means of preventing sex selection while avoiding medical paternalism and promoting the autonomy of women.

Attitude↗
PubMed1993

Geneticists approach ethics: an international survey.

Fletcher, Berg and Tranøy (1985) proposed that medical geneticists around the world would benefit from collective reflection on their preferred approaches to the most frequent of the difficult moral choices in practical genetics. In 1985-86, Wertz & Fletcher undertook a survey of geneticists' views in 19 nations. Results were widely disseminated. In this paper, the authors describe a new survey that they are conducting in 37 nations.

Attitude of Health Personnel↗
PubMed1992

Participation in biomedical research: the consent process as viewed by children, adolescents, young adults, and physicians.

We examined the capacity of children, adolescents, and young adults to assent and consent to participation in biomedical research, and what physician-investigators believe is important for patients in these age groups to know about such participation. The sample included 44 male and female subjects, ranging in age from 7 to 20 years, who were hospitalized to treat either pediatric cancer or obesity. The participants completed a structured interview that assessed knowledge of research participation using the elements outlined in the federal guidelines for informed consent. The study subjects were most knowledgeable about those elements of consent that assessed concrete information (e.g., freedom to ask questions, time elements involved, and the benefits of participation). They were less knowledgeable about those elements of informed consent that assessed abstract information (e.g., scientific vs therapeutic purpose of the study, and alternative treatments). Chronologic age was not related to knowledge of the elements of informed consent. The strategies that the study subjects used to reason about participation in research appeared to parallel their reasoning about other physical phenomena.

Adolescent↗
PubMed1992

Influence of political power, medical provincialism, and economic incentives on the rationing of surgical intensive care unit beds.

OBJECTIVE: To determine factors influencing rationing decisions in a surgical ICU during a temporary nursing shortage when two to six of the unit's 16 beds were closed. DESIGN: Blinded, concurrent data collection, retrospective chart review. SETTING: Surgical ICU. PATIENTS: All patients (n = 308) for whom a surgical ICU bed was requested were studied during a 3-month period. MEASUREMENTS AND MAIN RESULTS: Admitting patterns did not change and no attempts were made to limit admissions to more severely ill patients during times of the greatest shortage of surgical ICU beds. Contrary to findings in previous reports, the severity of illness of patients admitted to the surgical ICU decreased as bed availability and bed census decreased. Bed allocation across surgical services was influenced by factors other than medical suitability. Of major users, cardiothoracic surgery experienced the highest percentage (59%) of all patient admissions and lowest percentage (1.6%) of all denied admissions. General surgery experienced the lowest percentage (15%) of all admissions and highest percentage (10.4%) of all denied admissions, although these patients had the highest average Acute Physiology and Chronic Health Evaluation (APACHE II) scores for all patients admitted (17.7) and for patients denied admission (15.8). CONCLUSIONS: Surgical attending physicians rarely used other open inhouse ICU beds when surgical ICU beds were unavailable. Political power, medical provincialism, and income maximization overrode medical suitability in the provision of critical care services.

Adult↗
PubMed1992

Fetal therapy, ethics and public policies.

This article reviews the evolution of ethical problems in the first generation of experimental fetal therapy and the prevailing approaches to them. The problems include: review of risks/benefits, case selection, informed consent, twin pregnancies, and refusal of proven fetal therapy. The article further discusses ethical and public policy issues in the lack of U.S. federal support for fetal diagnosis, fetal therapy, and human embryo research. An argument is made for such support, beginning with experimental gene therapy in the fetus. Ethical principles are identified that support an obligation to learn to relieve and treat such human suffering at the earliest time. Contradictions of these principles are also identified in terms of research not now supported.

Aborted Fetus↗