Expression of a Fas-like proapoptotic molecule on the lymphocytes of Xenopus laevis.

Ligation of the externally expressed Fas (APO1/CD95) molecule will initiate programmed cell death (apoptosis), in many mammalian developing and adult cells. Fas-induced apoptosis has not been demonstrated with the cells of any non-mammalian vertebrate. We immunostained suspensions of splenocytes from adult Xenopus laevis, the South African clawed toad, with a polyclonal rabbit anti-human Fas antibody raised against the amino acid residues 321-335 of human Fas. The binding was specific, as it was dramatically reduced by preincubation of the antibody with the Fas peptide used to make it, but not with a Fas-ligand (FasL) peptide. The binding was enhanced after in vitro exposure of the splenocytes to phytahemagglutinin (PHA), a T cell mitogen and apoptogen in this species. Sections of developing Xenopus larval tissue were also immunostained with the polyclonal rabbit anti-human Fas antibody. Consistent binding of thymocytes and splenocytes was not observed until early metamorphosis in these immunological sites. A monoclonal mouse anti-human Fas antibody, previously used to stimulate apoptosis in mammalian cells, induced significant levels of apoptosis in adult Xenopus splenocytes and additionally, bound specifically to a splenocyte extract, as assayed by ELISA. Thus, a molecule on Xenopus splenocytes shares both structural and functional homologies with human Fas, indicating the evolutionary conservation within vertebrates of this means of initiating apoptosis.

Lessons learned from the tobacco industry's efforts to prevent the passage of a workplace smoking regulation.

OBJECTIVES: This study assessed the implementation of tobacco industry strategies to prevent a workplace smoking regulation. METHODS: Tobacco industry internal documents were identified; hearing transcripts for the affiliations, arguments, and positions regarding the regulation of testifiers were coded; and media coverage was analyzed. RESULTS: Tobacco industry strategies sought to increase business participation and economic discussions at public hearings and to promote unfavorable media coverage of the regulation. The percentage of business representatives opposing the regulation grew from 18% (5 to 28) to 57% (13 of 23) between the hearings. Economic arguments opposing the regulation rose from 25% (7 of 28) to 70% (16 of 23). Press coverage was neutral and did not increase during the period of the regulatory hearings. CONCLUSIONS: The tobacco industry was successful in implementing 2 of its 3 strategies but was not able to prevent passage of the comprehensive workplace regulation.

Science in regulatory policy making: case studies in the development of workplace smoking restrictions.

OBJECTIVE: To study the role of science related and other arguments in the development of workplace smoking regulations. DESIGN: Case study, content analysis SUBJECTS: Written commentaries and hearing transcripts on proposed indoor air regulations in Maryland and Washington. MAIN OUTCOME MEASURES: We coded each written commentary and hearing testimony for position toward the regulation, affiliation of the person submitting it, criteria used to evaluate science and scientific, ideological, economic, political, engineering and procedural arguments. RESULTS: In both states, opposition to the regulations came primarily from the tobacco industry, small businesses, and business organisations and appeared to be coordinated. There was little coordination of public health support for the regulations. Arguments about science were used more often by those opposed to the regulations than by those in favour. Supporters emphasised the quantity of the evidence, while opponents criticised its reliability, validity, and quality. Arguments not related to science (61% of total arguments; 459/751), were more common than scientific arguments (39% of total arguments; 292/751). Economic and ideological arguments were used to a similar extent by regulation supporters and opponents. CONCLUSIONS: Advocates can support health related regulations by submitting commentary emphasising the sound research base for regulation and countering criticisms of research. National coordination of these efforts could avoid duplication of effort and make more efficient use of limited public health resources.