An adverse outcome pathway for small intestinal tumors in mice involving chronic cytotoxicity and regenerative hyperplasia: a case study with hexavalent chromium, captan, and folpet.

Small intestinal (SI) tumors are relatively uncommon outcomes in rodent cancer bioassays, and limited information regarding chemical-induced SI tumorigenesis has been reported in the published literature. Herein, we propose a cytotoxicity-mediated adverse outcome pathway (AOP) for SI tumors by leveraging extensive target species- and site-specific molecular, cellular, and histological mode of action (MOA) research for three reference chemicals, the fungicides captan and folpet and the transition metal hexavalent chromium (Cr(VI)). The gut barrier functions through highly efficient homeostatic regulation of SI epithelial cell sloughing, regenerative proliferation, and repair, which involves the replacement of up to 1011 cells per day. This dynamic turnover in the SI provides a unique local environment for a cytotoxicity mediated AOP/MOA. Upon entering the duodenum, cytotoxicity to the villous epithelium is the molecular initiating event, as indicated by crypt elongation, villous atrophy/blunting, and other morphologic changes. Over time, the regenerative capacity of the gut epithelium to compensate declines as epithelial loss accelerates, especially at higher exposures. The first key event (KE), sustained regenerative crypt proliferation/hyperplasia, requires sufficient durations, likely exceeding 6 or 12 months, due to extensive repair capacity, to create more opportunities for the second KE, spontaneous mutation/transformation, ultimately leading to proximal SI tumors. Per OECD guidance, biological plausibility, essentiality, and empirical support were assessed using modified Bradford Hill considerations. The weight-of-evidence also included a lack of induced mutations in the duodenum after up to 90 days of Cr(VI) or captan exposure. The extensive evidence for this AOP, along with the knowledge that human exposures are orders of magnitude below those associated with KEs in this AOP, supports its use for regulatory applications, including hazard identification and risk assessment.

Enhancing & Mobilizing the POtential for Wellness & Emotional Resilience (EMPOWER) among Surrogate Decision-Makers of ICU Patients: study protocol for a randomized controlled trial.

BACKGROUND: Critical illness increases the risk for poor mental health outcomes among both patients and their informal caregivers, especially their surrogate decision-makers. Surrogates who must make life-and-death medical decisions on behalf of incapacitated patients may experience additional distress. EMPOWER (Enhancing & Mobilizing the POtential for Wellness & Emotional Resilience) is a novel cognitive-behavioral, acceptance-based intervention delivered in the intensive care unit (ICU) setting to surrogate decision-makers designed to improve both patients' quality of life and death and dying as well as surrogates' mental health. METHODS: Clinician stakeholder and surrogate participant feedback (n = 15), as well as results from an open trial (n = 10), will be used to refine the intervention, which will then be evaluated through a multisite randomized controlled trial (RCT) (n = 60) to examine clinical superiority to usual care. Feasibility, tolerability, and acceptability of the intervention will be evaluated through self-report assessments. Hierarchical linear modeling will be used to adjust for clustering within interventionists to determine the effect of EMPOWER on surrogate differences in the primary outcome, peritraumatic stress. Secondary outcomes will include symptoms of post-traumatic stress disorder, prolonged grief disorder, and experiential avoidance. Exploratory outcomes will include symptoms of anxiety, depression, and decision regret, all measured at 1 and 3 months from post-intervention assessment. Linear regression models will examine the effects of assignment to EMPOWER versus the enhanced usual care group on patient quality of life or quality of death and intensity of care the patient received during the indexed ICU stay assessed at the time of the post-intervention assessment. Participant exit interviews will be conducted at the 3-month assessment time point and will be analyzed using qualitative thematic data analysis methods. DISCUSSION: The EMPOWER study is unique in its application of evidence-based psychotherapy targeting peritraumatic stress to improve patient and caregiver outcomes in the setting of critical illness. The experimental intervention will be strengthened through the input of a variety of ICU stakeholders, including behavioral health clinicians, physicians, bereaved informal caregivers, and open trial participants. Results of the RCT will be submitted for publication in a peer-reviewed journal and serve as preliminary data for a larger, multisite RCT grant application. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03276559 . Retrospectively registered on 8 September 2017.

Attitudes Toward Individuals With Mental Illness and Substance Use Disorders Among Resident Physicians.

OBJECTIVE: Resident physicians frequently provide care for individuals diagnosed with mental illness and substance use disorders (SUDs). Clinicians-including psychiatrists and addiction professionals-have been shown to possess negative attitudes toward these individuals, which is concerning since negative attitudes may have an adverse impact on patient engagement, treatment, and outcomes. However, little is known about resident physicians' attitudes toward individuals with mental illness and SUDs. The objective of this study was to examine the attitudes of emergency medicine, internal medicine, and obstetrics-gynecology residents toward individuals with diagnoses of schizophrenia, multiple SUDs, co-occurring schizophrenia and SUDs, and major depressive disorder. METHODS: A web-based questionnaire, including demographic information, level of training, and the 11-item Medical Condition Regard Scale (MCRS) for individuals with 4 different diagnoses, which assesses the degree to which clinicians find individuals with a given medical condition to be enjoyable, treatable, and worthy of medical resources, was sent to residents across the United States from May 2016 to April 2017. RESULTS: A total of 411 resident physicians completed the questionnaire. Respondents had more negative attitudes toward individuals with diagnoses of SUDs with and without schizophrenia than toward those individuals with diagnoses of schizophrenia or major depressive disorder alone. Senior residents possessed more negative attitudes toward individuals with SUDs than did junior residents. Emergency medicine residents had more negative attitudes than the other resident physician groups. CONCLUSIONS: The attitudes of resident physicians toward individuals with SUDs with and without schizophrenia were negative and were worse among emergency medicine residents and senior residents. Additional research and programmatic work are needed to understand the reasons for these negative attitudes and to develop interventions during residency training to improve them.

Assessing Decision Making Capacity for Do Not Resuscitate Requests in Depressed Patients: How to Apply the "Communication" and "Appreciation" Criteria.

The Patient Self Determination Act (PSDA) of 1991 brought much needed attention to the importance of advance care planning and surrogate decision-making. The purpose of this law is to ensure that a patient's preferences for medical care are recognized and promoted, even if the patient loses decision-making capacity (DMC). In general, patients are presumed to have DMC. A patient's DMC may come under question when distortions in thinking and understanding due to illness, delirium, depression or other psychiatric symptoms are identified or suspected. Physicians and other healthcare professionals working in hospital settings where medical illness is frequently comorbid with depression, adjustment disorders, demoralization and suicidal ideation, can expect to encounter ethical tension when medically sick patients who are also depressed or suicidal request do not resuscitate orders.

Donors in chains: psychosocial outcomes of kidney donors in paired exchange.

BACKGROUND: Kidney paired donation chains are initiated by nondirected donors and propagated by donors within the chain of transplants, or chain donors. OBJECTIVE: To compare psychosocial and functional outcomes, and to test coercion, of chain donors in paired exchange versus traditional directed donors who have an established relationship with the recipient. METHODS: Thirty chain donors from a transplant center who were part of the National Kidney Registry paired exchange program were compared with 34 traditional donors who donated around the same time. Participants completed online surveys: the postdonation section of the Living Donor Expectancies Questionnaire was used to assess psychosocial and functional outcomes 1 to 6 years after donation. A survey to assess coercion was used as well. RESULTS: Chain donors and traditional donors were similar in terms of sex, race, age, and time after donation. The 2 groups had similar altruistic motives in donating their kidney, and both types of donors mentioned psychological benefits. No differences were found on questions regarding psychosocial outcomes save for the "quid pro quo scale" (P= .01), which suggested that the traditional donors felt more that the recipients are indebted to them. The 2 groups did not differ significantly in the coercion measure. Pressure to donate and stress of donation were not greater in chain donors than traditional donors (P= .60). CONCLUSION: Kidney donors in kidney paired donation chains do as well as traditional donors psychosocially without any increased tendency toward experiencing coercion.

Relevance weighting of tier 1 endocrine screening endpoints by rank order.

Weight of evidence (WoE) approaches are recommended for interpreting various toxicological data, but few systematic and transparent procedures exist. A hypothesis-based WoE framework was recently published focusing on the U.S. EPA's Tier 1 Endocrine Screening Battery (ESB) as an example. The framework recommends weighting each experimental endpoint according to its relevance for deciding eight hypotheses addressed by the ESB. Here we present detailed rationale for weighting the ESB endpoints according to three rank ordered categories and an interpretive process for using the rankings to reach WoE determinations. Rank 1 was assigned to in vivo endpoints that characterize the fundamental physiological actions for androgen, estrogen, and thyroid activities. Rank 1 endpoints are specific and sensitive for the hypothesis, interpretable without ancillary data, and rarely confounded by artifacts or nonspecific activity. Rank 2 endpoints are specific and interpretable for the hypothesis but less informative than Rank 1, often due to oversensitivity, inclusion of narrowly context-dependent components of the hormonal system (e.g., in vitro endpoints), or confounding by nonspecific activity. Rank 3 endpoints are relevant for the hypothesis but only corroborative of Ranks 1 and 2 endpoints. Rank 3 includes many apical in vivo endpoints that can be affected by systemic toxicity and nonhormonal activity. Although these relevance weight rankings (WREL ) necessarily involve professional judgment, their a priori derivation enhances transparency and renders WoE determinations amenable to methodological scrutiny according to basic scientific premises, characteristics that cannot be assured by processes in which the rationale for decisions is provided post hoc.

Community pharmacists' occupational satisfaction and stress: a profession in jeopardy?

OBJECTIVES: To quantify and model drivers of community pharmacists' self-reported levels of occupational satisfaction and stress and to identify key segments for possible intervention by the profession. DESIGN: Descriptive nonexperimental study. SETTING: United States during January to February 2012. PARTICIPANTS: 303 independent and community chain pharmacists. INTERVENTION: Online survey instrument of previously validated occupational stress and satisfaction attribute batteries. RESULTS: Participants reported a high level of dissatisfaction with current employment, with more than 50% stating that they were considering quitting their jobs. Dissatisfaction was higher among those with a doctor of pharmacy degree and those employed in community chains. Occupational stress and satisfaction were highly correlated with the intention to search for a new position. Approximately 20% of respondents felt that stress from their employment adversely affected their mental health and well-being, physical health, quality of the work, or relationships with family and friends. CONCLUSION: Substantive levels of occupational dissatisfaction and stress exist among pharmacists currently in community practice. These negative attributes are associated with a damaging promotion of community practice-a marker of a negative trajectory in sustaining this practice environment. The results of this study have implications for the health care industry, commercial pharmacy vendors, independent pharmacies, the profession, and academic training institutions as they prepare the pharmacy workforce of the future for potentially dissatisfying and stressful work environments.

Relationship of metabolism and cell proliferation to the mode of action of fluensulfone-induced mouse lung tumors: analysis of their human relevance using the IPCS framework.

Species-specific lung tumors in the mouse are induced by a number of chemicals. The underlying cause appears to be a high metabolic activity of mouse lung, due to relatively high abundance of Clara cells in mice compared with humans and the mouse-specific cytochrome P450 isoform 2f2 in the Clara cells. The chemicals are activated to reactive intermediates, leading to local cytotoxicity or mitogenicity resulting in increased cell proliferation and tumors. Rats have lower metabolic activity than mice (already below the threshold needed to cause lung tumors upon lifetime exposure) and activity in humans is lower than in rats. The carcinogenic risk for human lung is low for this mode of action (MOA). Fluensulfone has shown an increased incidence of lung adenomas in mice, but not in rats, at high doses. Fluensulfone is not genotoxic. MOA studies were conducted investigating key events of the postulated MOA. Fluensulfone is extensively metabolized by mouse lung microsomes, whereas no metabolic activity is seen with human lung microsomes. Cyp 2f2 is a major contributor in fluensulfone's metabolism and Cyp 2e1 is not involved. Furthermore, administration of fluensulfone to mice led to an early increase in Clara cell proliferation. The International Programme on Chemical Safety (IPCS) MOA and human relevance framework was used to evaluate the collective data on fluensulfone. We concluded that fluensulfone leads to species-specific mouse lung tumors and that these tumors are likely not relevant to human hazard or risk.

Sociability and brain development in BALB/cJ and C57BL/6J mice.

Sociability--the tendency to seek social interaction--propels the development of social cognition and social skills, but is disrupted in autism spectrum disorders (ASD). BALB/cJ and C57BL/6J inbred mouse strains are useful models of low and high levels of juvenile sociability, respectively, but the neurobiological and developmental factors that account for the strains' contrasting sociability levels are largely unknown. We hypothesized that BALB/cJ mice would show increasing sociability with age but that C57BL/6J mice would show high sociability throughout development. We also hypothesized that littermates would resemble one another in sociability more than non-littermates. Finally, we hypothesized that low sociability would be associated with low corpus callosum size and increased brain size in BALB/cJ mice. Separate cohorts of C57BL/6J and BALB/cJ mice were tested for sociability at 19-, 23-, 31-, 42-, or 70-days-of-age, and brain weights and mid-sagittal corpus callosum area were measured. BALB/cJ sociability increased with age, and a strain by age interaction in sociability between 31 and 42 days of age suggested strong effects of puberty on sociability development. Sociability scores clustered according to litter membership in both strains, and perinatal litter size and sex ratio were identified as factors that contributed to this clustering in C57BL/6J, but not BALB/cJ, litters. There was no association between corpus callosum size and sociability, but smaller brains were associated with lower sociability in BALB/cJ mice. The associations reported here will provide directions for future mechanistic studies of sociability development.

Folpet-induced short term cytotoxic and proliferative changes in the mouse duodenum.

Folpet, an agricultural fungicide, induces tumors in the mouse gastrointestinal tract, primarily in the duodenum. Bioassays show a threshold for tumors at ~1000 ppm dietary administration. We investigated the early histologic changes to the mouse duodenum in mice fed a diet containing 6000 ppm folpet for 28 days. Reversibility of folpet-induced changes was evaluated after treatment for 28 days and a recovery period of 17 days. Macroscopic changes in the cecum (dilatation) and duodenum (roughening) were evident by day 7, continued through day 28, then returned to normal by recovery day 17. The duodenal mucosa also appeared to be thickened. Macroscopic changes to the forestomach were also evident as a rough surface or depressions; they also decreased in incidence and severity in the recovery animals. Histologic changes of the duodenum (crypt cell hyperplasia, villous hypertrophy, numerous intraepithelial lymphocytes, and elongation of epithelial columnar cells) were evident in all treated mice by day 7 and continued and increased in severity through 28 days of administration. The incidence and severity of these findings was reduced on recovery day 17, indicating reversibility. Histologic changes (epithelial hyperplasia and hyperkeratosis) of the non-glandular squamous epithelium in the forestomach occurred later than the changes to the duodenum. The incidence and severity of these changes also lessened by recovery day 17. These early histologic changes support a non-DNA reactive mode of action for folpet carcinogenicity in mice involving the key events of mucosal cytotoxicity with consequent regenerative proliferation. Exposures that are not sufficient to produce cytotoxicity would also not lead to tumor formation.

Carcinogenic mode of action of folpet in mice and evaluation of its relevance to humans.

A framework has been evolving for evaluation of mode of action (MOA) of rodent toxicity and carcinogenicity findings and their relevance to humans. Folpet produces duodenal glandular tumors in mice, but is not carcinogenic in rats. A wealth of information is available regarding folpet's mode of action, providing an excellent example of how this tumor can be evaluated using this framework. Folpet reacts with thiol groups, and is rapidly hydrolyzed at pH 7. Both reactions produce thiophosgene that reacts with thiols and other functional groups. Folpet is not genotoxic in vivo. At sufficiently high, prolonged dietary doses, folpet irritates the mouse duodenum, resulting in cytotoxicity with consequent regenerative proliferation and ultimately tumor development. Forestomach lesions secondary to cytotoxicity are also induced. Dogs have stomachs similar to humans and show no evidence of gastrointestinal toxicity or tumor formation at exposure levels at least as high as rodents. The data support a MOA in mice involving cytotoxicity and regenerative proliferation. Based on MOA analysis and assessment of human relevance, folpet, like captan, another trichloromethylthio-related fungicide with similar toxic and carcinogenic effects, is not likely to be a human carcinogen at dose levels that do not cause cytotoxicity and regenerative proliferation.

Genetic toxicology of folpet and captan.

Folpet and captan are fungicides whose genotoxicity depends on their chemical reaction with thiols. Multiple mutagenicity tests have been conducted on these compounds due to their positive activity in vitro and their association with gastrointestinal tumors in mice. A review of the collective data shows that these compounds have in vitro mutagenic activity but are not genotoxic in vivo. This dichotomy is primarily due to the rapid degradation of folpet and captan in the presence of thiol-rich matrices typically found in vivo. Genotoxicity has not been found in the duodenum, the mouse tumor target tissue. It is concluded that folpet like captan presents an unlikely risk of genotoxic effects in humans.

Captan: transition from 'B2' to 'not likely'. How pesticide registrants affected the EPA Cancer Classification Update.

On 24 November 2004 EPA changed the cancer classification of captan from a 'probable human carcinogen' (Category B2) to 'not likely' when used according to label directions. The new cancer classification considers captan to be a potential carcinogen at prolonged high doses that cause cytotoxicity and regenerative cell hyperplasia. These high doses of captan are many orders of magnitude above those likely to be consumed in the diet, or encountered by individuals in occupational or residential settings. This revised cancer classification reflects EPA's implementation of their new cancer guidelines. The procedures involved in the reclassification effort were agreed upon with EPA and involved an Independent Transparent Review as it related to four components that formed the basis of the original 1986 B2 classification: mouse tumors; rat tumors; mutagenicity; and structural similarity to other carcinogens. A Peer Review Panel organized and administered by Toxicology Excellence for Risk Assessment (TERA) met on 2-3 September 2003. The Panel concluded that captan acted through a non-mutagenic threshold mode of action that required prolonged irritation of the duodenal villi as the initial key event. EPA's Cancer Assessment Review Committee (CARC) met on 9 June 2004 and endorsed the Peer Review findings. EPA intended to have the FIFRA Scientific Advisory Panel (SAP) consider the basis for this reclassification but found the science was robust and judged that a SAP review was not warranted. Using the revised classification, the margin of exposure is approximately 1,200,000, supporting the 'not likely' characterization.