Estrogen metabolism is altered in most, if not all, breast cancer tumors. These alterations primarily lead to the formation of the catechol estrogen metabolites, 2- and 4-hydroxyestrogens, which can generate superoxide anion radicals (O(2)(*)(-)) through the redox cycling of semiquinone/quinone derivatives. In breast cancer cells, the activity of nitric oxide synthase is also frequently elevated, resulting in an increased level of exposure to nitric oxide ((*)NO). Since (*)NO rapidly reacts with O(2)(*)(-) to produce the peroxynitrite anion (ONOO(-)), this study was undertaken to determine whether ONOO(-) can be generated when 2- and 4-hydroxyestrogens are incubated in vitro with (*)NO donor compounds. Using dihydrorhodamine 123 as a specific probe for ONOO(-) formation, a ratio of 100 microM dipropylenetriamine NONOate (DPTA/NO) to 10 microM 4-hydroxyestradiol (4-OHE(2)) gave an optimal ONOO(-) production of 11.9 +/- 1.9 microM (mean +/- SD). Quantification of ONOO(-) was not modified by mannitol, supporting the idea that the hydroxyl radical was not involved. This production of ONOO(-) required the presence of the catechol structure of estrogen metabolites since all methoxyestrogens that were tested were inactive. Hydroxyestrogen metabolites derived from estradiol showed the same efficiency in producing ONOO(-) as those originating from estrone. With DPTA/NO, the 4-hydroxyestrogens generated 30-40% more ONOO(-) than the 2-hydroxyestrogens. Optimal production of ONOO(-) was assessed with DPTA/NO and diethylenetriamine NONOate (initial (*)NO generation rates of 0.76 and 0.08 microM min(-1), respectively). With faster (*)NO-releasing compounds, such as diethylamine NONOate and spermine NONOate, lower levels of ONOO(-) were detected. These data suggest that once the optimal concentration of (*)NO was obtained, the reaction between (*)NO and 4-OHE(2) was saturated. The excess of (*)NO would probably react with aqueous oxygen to form nitrite (NO(2)(-)). Since the third-order reaction rate for the reaction between 2(*)NO and O(2) is 2 x 10(6) M(-2) s(-1), it can therefore be suggested that the reaction between (*)NO and 4-OHE(2) occurs at a faster rate.
Objective To describe the type and level of ethical integration in published health technology assessment (HTA) reports and systematically identify the ethical approaches utilized. Methods A literature search was conducted with the Google™ search engine using the keyword “ethic” between 1 January 2015 and 20 August 2019. Only HTA assessment reports with a section on ethics were retained and classified according to their level of ethical integration: no ethical analysis, ethical issues highlighted, assessments according to legal or social norms, and assessments from a moral or axiological perspective—using a qualitative methodology to distinguish such integration. Results This review yielded 188 reports with a section identified as being on ethics, produced by seventeen HTA agencies in eleven countries. One hundred and thirty-six reports did not develop an ethical analysis, thirty-one highlighted ethical issues, seventeen conducted a norm-based ethical assessment using a descriptive approach grounded in social norms, and four developed an assessment grounded in a moral or axiological perspective. The bioethical “four-principles” framework was used, but mainly for presenting ethical issues and not as a moral framework. Conclusions The majority of reports featuring a section on ethics mention ethical considerations without ethical analysis. Ethical issues are grouped with legal, social, and organizational issues and treated as contextual considerations that decision makers should be aware of. When reports present systematic norm-based ethical assessments from a descriptive perspective or ethical assessment based on a moral or axiological perspective, there is a tendency to ground these analyses in frameworks created for the purpose and reliant on a concept of ethics supporting them.
Introduction:Eliciting implicit value-judgments (VJs) in the HTA process is one way of integrating ethics in HTA since the latter is recognized as a value-laden process. An analysis of the diversity of opinions on implicit VJs in HTA and of their role, highlights the connection there exists between VJs and the different decisions involved in the whole HTA process. Such a link is corroborated by a conceptual analysis of VJ using a speech-act philosophical approach grounded in the philosophy of language, since VJs are linked with normative speech-acts such as commands, recommendations and advices.Methods:We propose an analysis of the published citations mentioning VJs, extracted from our systematic review on the challenges of integrating ethics in HTA. In order to do so, those quotes were categorized in a chart, the latter of which presents: (i) the different steps of decision-making in the HTA process, (ii) the description of the implicit VJ(s) and (iii) the criteria involved. This chart was elaborated with the participation of the HTA local evaluators involved as co-investigators in our research group. The final version was discussed, debated and validated by the entire research group.Results:The chart shows 18 decision-making steps in the HTA process in which twenty-three implicit VJs can be observed. The range of such VJs encompasses the whole HTA process from the initial mandate to the agency presenting the decisional issues, to the dissemination of the final report. The published citations gathered for each category compile different expectations on the elicitation of the implicit VJs, thus making the latter VJs more explicit.Conclusions:This chart allows a better understanding of the expectations that are at the core of the appeal for more transparency in the HTA process, since stakeholders need to understand which value-judgments the final conclusion of a report is relying on.
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