Firearm ownership factors and cognitive functioning: A preliminary study.

Recent studies have suggested that owning a firearm for the purpose of protection and intending to acquire a firearm within the next year are associated with disrupted cognitive-affective processes that may increase firearm suicide risk. Prior studies were limited by self-report measures and would benefit from the utilization of objective indicators of cognitive functioning to clarify associations between firearm ownership and cognitive-affective states. The present study examined objective cognitive performance in a sample of U.S. adults in relation to firearm ownership variables. Based on prior studies, we hypothesized that protective owners and individuals with the intention to acquire a firearm within the next year would demonstrate reduced performance on decision-making, mental flexibility, and emotional bias tasks. A total of 112 participants (61% female, 79% white) completed objective cognitive tasks following completion of a larger survey study through ResearchMatch. Results indicated that intention to purchase a firearm within the next year was not associated with cognitive functioning but was associated with an array of heightened psychiatric symptoms. Owning a firearm for the purpose of protection was associated with decreased mental flexibility relative to non-owners, but no differences were seen for decision-making or emotional bias. These findings represent the first attempt to examine underlying objective cognitive processes related to firearm ownership, and implications for future research are discussed.

Suicide-related cognitions and emotional bias performance in a community sample.

BACKGROUND: Suicide is theorized to be connected to social interactions and feelings of belongingness. Those with suicide-related cognitions (SRCs) demonstrate attentional bias toward negative or suicide-related words, which can lead to increased feelings of rejection or alienation. As social interactions employ both verbal and nonverbal cues, there exists a gap in understanding how perception of emotional expressions can contribute to the development or exacerbation of suicidal ideation. METHODS: The current sample (N = 114, 60.5 % female, 74.6 % white) completed the Suicide Cognitions Scale-Revised (SCS-R) and Patient Health Questionnaire (PHQ-9) to assess SRCs and depression severity. The Emotional Bias Task (EBT) was used to assess emotional response latency. RESULTS: Multiple regression analyses on EBT results showed that endorsement of SRCs and depression severity were not associated with any particular emotional response bias. However, presence of SRCs showed an association with longer latencies to identify ambiguous emotional expressions, even when controlling for depressive symptoms and age LIMITATIONS: Measures were self-completed online. Relative homogeneity of the sample and cross-sectional design limits interpretation of the results. CONCLUSIONS: Those with more severe SRCs take longer to recognize positive, nonverbal cues. Irregular processing of positive emotional stimuli combined with bias toward negative verbal cues could worsen feelings of rejection or alienation in social interactions, therefore increasing risk of developing SI. This suggests that interventions focusing on allocation of attentional resources to process positive social cues may be beneficial for those with SRCs to reduce severity and risk of suicide.

Associations among posttraumatic stress disorder symptoms, suicidal ideation, suicide attempts, and reward discounting.

Posttraumatic stress disorder (PTSD) is associated with suicidal thoughts and behaviours. Decision-making processes and risk-taking are prominent for coping in both, but the implications for guaranteed and probabilistic reward discounting, important components in behavioural decision-making processes, are unclear. This study explored the relationships between PTSD and suicide risk with tendencies towards devaluing guaranteed rewards that are larger but delayed (i.e., delay discounting; DD) and devaluing larger but uncertain rewards (i.e., probability discounting; PD) for immediate but smaller rewards. The current study evaluated 498 participants (majority male [51.4%] and white [63.8%]; 33.3% screening positive for probable PTSD; 19.2% with lifetime suicide attempts; 30.8% with recent suicide ideation) on both delayed discounting and PD tasks. Provisional PTSD diagnosis, but not suicide attempts or ideation, was associated with increased PD (i.e., more devaluation of uncertain rewards). Conversely, PTSD interacted with both attempt history and ideation to predict increased delayed discounting (i.e., more devaluing of greater but delayed rewards). These results highlight how those with PTSD symptoms assign valuations to rewards, as well as how the addition of suicide risk interacts to impact these decision-making processes. While further research is needed, this suggests potential implications for treatment as they may benefit from structuring progress in smaller, more immediate goals.

Examining the roles of disability-related body esteem and perceived burdensomeness in suicidal ideation among adults with vision- and mobility-related disabilities.

PURPOSE/OBJECTIVE: People with disabilities (PWD) generally exhibit an increased risk of suicidal ideation (SI) and behaviors. Underlying cognitive states, namely perceived burdensomeness, have been identified as a contributor to the increased risk of suicidal thoughts and behaviors in PWD. However, the role of body esteem in the development of SI in this population remains unexamined, despite its salience in other populations. In this study, we examined whether the interaction of perceived burdensomeness and body esteem contributed to the perceived likelihood of future SI among PWD, and whether this relationship was further moderated by disability type. METHOD: Participants included 119 adults with self-reported vision- and mobility-related disabilities who participated in a larger study focused on disability and suicide involving interviews and self-report measures. We examined the interaction between perceived burdensomeness and disability-related body esteem on self-reported likelihood of future SI and whether this interaction was further moderated by disability type (i.e., vision- or mobility-related disability). RESULTS: Greater perceived burdensomeness was associated with a greater perceived likelihood of future SI only for participants with vision impairments and at low levels of body esteem. CONCLUSIONS/IMPLICATIONS: The combination of experiences of perceived burdensomeness and low body esteem may be particularly relevant to SI among people with vision-related versus mobility-related disabilities. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Carbonyl Reductase 1 Plays a Significant Role in Converting Doxorubicin to Cardiotoxic Doxorubicinol in Mouse Liver, but the Majority of the Doxorubicinol-Forming Activity Remains Unidentified.

Doxorubicin is a widely used cancer therapeutic, but its effectiveness is limited by cardiotoxic side effects. Evidence suggests cardiotoxicity is due not to doxorubicin, but rather its metabolite, doxorubicinol. Identification of the enzymes responsible for doxorubicinol formation is important in developing strategies to prevent cardiotoxicity. In this study, the contributions of three murine candidate enzymes to doxorubicinol formation were evaluated: carbonyl reductase (Cbr) 1, Cbr3, and thioredoxin reductase 1 (Tr1). Analyses with purified proteins revealed that all three enzymes catalyzed doxorubicin-dependent NADPH oxidation, but only Cbr1 and Cbr3 catalyzed doxorubicinol formation. Doxorubicin-dependent NADPH oxidation by Tr1 was likely due to redox cycling. Subcellular fractionation results showed that doxorubicin-dependent redox cycling activity was primarily microsomal, whereas doxorubicinol-forming activity was exclusively cytosolic, as were all three enzymes. An immunoclearing approach was used to assess the contributions of the three enzymes to doxorubicinol formation in the complex milieu of the cytosol. Immunoclearing Cbr1 eliminated 25% of the total doxorubicinol-forming activity in cytosol, but immunoclearing Cbr3 had no effect, even in Tr1 null livers that overexpressed Cbr3. The immunoclearing results constituted strong evidence that Cbr1 contributed to doxorubicinol formation in mouse liver but that enzymes other than Cbr1 also played a role, a conclusion supported by ammonium sulfate fractionation results, which showed that doxorubicinol-forming activity was found in fractions that contained little Cbr1. In conclusion, the results show that Cbr1 accounts for 25% of the doxorubicinol-forming activity in mouse liver cytosol but that the majority of the doxorubicinol-forming activity remains unidentified. SIGNIFICANCE STATEMENT: Earlier studies suggested carbonyl reductase (Cbr) 1 plays a dominant role in converting chemotherapeutic doxorubicin to cardiotoxic doxorubicinol, but a new immunoclearing approach described herein shows that Cbr1 accounts for only 25% of the doxorubicinol-forming activity in mouse liver cytosol, that two other candidate enzymes-Cbr3 and thioredoxin reductase 1-play no role, and that the majority of the activity remains unidentified. Thus, targeting Cbr1 is necessary but not sufficient to eliminate doxorubicinol-associated cardiotoxicity; identification of the additional doxorubicinol-forming activity is an important next challenge.

Enhanced reductive dechlorination in columns treated with edible oil emulsion.

The effect of edible oil emulsion treatment on enhanced reductive dechlorination was evaluated in a 14 month laboratory column study. Experimental treatments included: (1) emulsified soybean oil and dilute HCl to inhibit biological activity; (2) emulsified oil only; (3) emulsified oil and anaerobic digester sludge; and (4) continuously feeding soluble substrate. A single application of emulsified oil was effective in generating strongly reducing, anaerobic conditions for over 14 months. PCE was rapidly reduced to cis-DCE in all three live columns. Bioaugmentation with a halorespiring enrichment culture resulted in complete dechlorination of PCE to ethene in the soluble substrate column (yeast extract and lactate). However, an additional treatment with a pulse of yeast extract and bioaugmentation culture was required to stimulate complete dechlorination in the emulsion treated columns. Once the dechlorinating population was established, the emulsion only column degraded PCE from 90-120 microM to below detection with concurrent ethene production in a 33 day contact time. The lower biodegradation rates in the emulsion treated columns compared to the soluble substrate column suggest that emulsified oil barriers may require a somewhat longer contact time for effective treatment. In the HCl inhibited column, partitioning of PCE to the retained oil substantially delayed PCE breakthrough. However, reduction of PCE to more soluble degradation products (cis-DCE, VC and ethene) greatly reduced the impact of oil-water partitioning in live columns. There was only a small decline in the hydraulic conductivity (K) of column #1 (low pH+emulsion, K(final)/K(initial)=0.57) and column #2 (live+emulsion, K(final)/K(initial)=0.73) indicating emulsion injection did not result in appreciable clogging of the clayey sand. However, K loss was greater in column #3 (sludge+emulsion, K(final)/K(initial)=0.12) and column #4 (soluble substrate, K(final)/K(initial)=0.03) indicating clogging due to biomass and/or gas production can be significant.