Effects of mercury and probiotics on the microbiome and behavior of the prairie vole (Microtus ochrogaster)

The digestive tract is home to trillions of microorganisms. In addition to helping with digestion, these microbes can have profound effects on host mood and behavior through a pathway known as the microbiome-gut-brain axis. By this pathway, changes in the intestinal microbial community can alter anxiety behaviors, depression, and sociability.The aim of the current study was to characterize the impacts of mercury exposure and probiotic administration on both the gut microbiome and the anxiety and social behaviors of the prairie vole (Microtus ochrogaster). Following four weeks of exposure to 60 ppm mercuric chloride (HgCl2), anxiety-like behaviors were significantly elevated in the voles. Subsequent administration of a potentially-probiotic Lactobacillus suspension (3.8 x 108 CFU / ml) for two weeks was not effective at remediating anxiety behaviors or the previously-reported decrease in sociability.Microbiome analysis revealed significant changes in the microbial communities in response to mercury exposure and the administration of both the Lactobacillus suspension and its resuspension agent alone (0.15% maltodextrin). Several microorganisms were also correlated with specific anxiety and social behaviors, highlighting the strong possibility of microbiome-gut-brain axis involvement in changes in these behaviors.Overall, the current study provides clarity into the impacts of mercury and probiotics on the microbial community and identifies several specific microorganisms that may alter prairie vole behavior via the microbiome-gut-brain axis

Southern Ocean drives multidecadal atmospheric CO2 rise during Heinrich Stadials

The last glacial period was punctuated by cold intervals in the North Atlantic region that culminated in extensive iceberg discharge events. These cold intervals, known as Heinrich Stadials, are associated with abrupt climate shifts worldwide. Here, we present CO2 measurements from the West Antarctic Ice Sheet Divide ice core across Heinrich Stadials 2 to 5 at decadal-scale resolution. Our results reveal multi-decadal-scale jumps in atmospheric CO2 concentrations within each Heinrich Stadial. The largest magnitude of change (14.0 ± 0.8 ppm within 55 ± 10 y) occurred during Heinrich Stadial 4. Abrupt rises in atmospheric CO2 are concurrent with jumps in atmospheric CH4 and abrupt changes in the water isotopologs in multiple Antarctic ice cores, the latter of which suggest rapid warming of both Antarctica and Southern Ocean vapor source regions. The synchroneity of these rapid shifts points to wind-driven upwelling of relatively warm, carbon-rich waters in the Southern Ocean, likely linked to a poleward intensification of the Southern Hemisphere westerly winds. Using an isotope-enabled atmospheric circulation model, we show that observed changes in Antarctic water isotopologs can be explained by abrupt and widespread Southern Ocean warming. Our work presents evidence for a multi-decadal- to century-scale response of the Southern Ocean to changes in atmospheric circulation, demonstrating the potential for dynamic changes in Southern Ocean biogeochemistry and circulation on human timescales. Furthermore, it suggests that anthropogenic CO2 uptake in the Southern Ocean may weaken with poleward strengthening westerlies today and into the future.Peer reviewe

Medical Care Disruptions During the First Six-Months of the COVID19 Pandemic: The Experience of Older Breast Cancer Survivors

Purpose Older cancer survivors required medical care during the COVID-19 pandemic despite infection risks, but there are limited data on medical care in this age group. Methods. We evaluated care disruptions in a longitudinal cohort of non-metastatic breast cancer survivors ages 60-98 from five US regions (n=321). Survivors completed a web-based or telephone survey from May 27, 2020 to September 11, 2020. Care disruptions included self-reported interruptions in ability to see doctors, receive treatment or supportive therapies, or fill prescriptions. Logistic regression models evaluated bivariate and multivariate associations between care disruptions and education, medical, psychosocial and COVID-19-related factors. Multivariate models included age, county COVID-19 rates, comorbidity and post-diagnosis time. Results. There was a high response rate (n=262, 81.6%). Survivors were 32.2 months post-diagnosis (SD 17.5, range 4-73). Nearly half (48%) reported a medical disruption. The unadjusted odds of care disruptions were significantly higher with more education (OR 1.23 per one-year increase, 95% CI 1.09-1.39, p =0.001) and greater depression (OR 1.04 per one-point increase in CES-D score, CI 1.003-1.08, p=0.033); tangible support decreased the odds of disruptions (OR 0.99, 95% CI 0.97-0.99 per one-point increase, p=0.012). There was a trend for associations between disruptions and comorbidity (unadjusted OR 1.13 per 1 added comorbidity, 95% CI 0.99-1.29, p=0.07). Adjusting for covariates, only higher education (p=0.001) and tangible social support (p=0.006) remained significantly associated with having care disruptions. Conclusions. Older breast cancer survivors reported high rates of medical care disruptions during the COVID-19 pandemic and psychosocial factors were associated with care disruptions

Protective Effects of APOE ε2 Genotype on Cognition in Older Breast Cancer Survivors: The Thinking and Living With Cancer Study

Background: Cancer-related cognitive decline (CRCD) has been linked to apolipoprotein E (APOE) gene ε4 polymorphisms. APOE ε4 polymorphisms are also the strongest genetic risk for late-onset Alzheimer disease (AD), whereas ε2 polymorphisms protect against AD. However, the effects of ε2 polymorphisms on CRCD have not been evaluated. Methods: We evaluated nonmetastatic breast cancer survivors (n = 427) and matched noncancer controls (n = 407) ages 60-98 years assessed presystemic therapy from August 2010 to December 2017 with annual follow-up to 24 months. Neuropsychological assessment measured attention, processing speed, executive function, and learning and memory. Linear mixed-effects models tested the effects of having an ε2 allele (vs none) on longitudinal cognitive domain z scores by treatment group (chemotherapy with or without hormonal therapy, hormonal therapy, and control) controlling for covariates; participants with ε2/ε4 genotype were excluded. Sensitivity analyses examined effects of other covariates and any ε4 positivity. Results: There was an interaction with genotype for attention, processing speed, and executive functioning domain scores (Beta = 0.32, 95% confidence interval = 0.00 to 0.65); the chemotherapy group with an ε2 allele had higher scores at baseline and maintained higher scores over time compared with those without an ε2 allele, and this protective effect was not seen for other groups. There was no effect of ε2 on learning and memory domain scores. Conclusions: APOE ε2 polymorphisms may protect against CRCD in older breast cancer survivors receiving chemotherapy. With replication, this information could be useful for survivorship care and informing future studies of possible links to AD and defining mechanisms of protection

Loneliness and mental health during the COVID‐19 pandemic in older breast cancer survivors and noncancer controls

This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Background: The coronavirus disease 2019 (COVID-19) pandemic has had wide-ranging health effects and increased isolation. Older with cancer patients might be especially vulnerable to loneliness and poor mental health during the pandemic. Methods: The authors included active participants enrolled in the longitudinal Thinking and Living With Cancer study of nonmetastatic breast cancer survivors aged 60 to 89 years (n = 262) and matched controls (n = 165) from 5 US regions. Participants completed questionnaires at parent study enrollment and then annually, including a web-based or telephone COVID-19 survey, between May 27 and September 11, 2020. Mixed-effects models were used to examine changes in loneliness (a single item on the Center for Epidemiologic Studies-Depression [CES-D] scale) from before to during the pandemic in survivors versus controls and to test survivor-control differences in the associations between changes in loneliness and changes in mental health, including depression (CES-D, excluding the loneliness item), anxiety (the State-Trait Anxiety Inventory), and perceived stress (the Perceived Stress Scale). Models were adjusted for age, race, county COVID-19 death rates, and time between assessments. Results: Loneliness increased from before to during the pandemic (0.211; P = .001), with no survivor-control differences. Increased loneliness was associated with worsening depression (3.958; P < .001) and anxiety (3.242; P < .001) symptoms and higher stress (1.172; P < .001) during the pandemic, also with no survivor-control differences. Conclusions: Cancer survivors reported changes in loneliness and mental health similar to those reported by women without cancer. However, both groups reported increased loneliness from before to during the pandemic that was related to worsening mental health, suggesting that screening for loneliness during medical care interactions will be important for identifying all older women at risk for adverse mental health effects of the pandemic

Validating the PROMIS cognitive function short form in cancer survivors.

PURPOSE: The Patient-Reported Outcome Measurement Information System Cognitive Function Short Form 8a&nbsp; (PROMIS Cog) could provide a shorter, useful alternative to the often used Functional Assessment of Cancer Therapy - Cognition (FACT-Cog) in research&nbsp;and clinical care. This study aimed to determine the convergent validity and internal reliability of the PROMIS Cog in 3 separate samples of breast cancer survivors and to explore clinical cut points. METHODS: Data from three samples of breast cancer survivors were used for this secondary analysis. Convergent validity was determined by evaluating correlation strength among the derived PROMIS Cog and measures of depression, anxiety, stress, fatigue, sleep, loneliness, the FACT-Cog . Clinical cut-points for the PROMIS Cog were determined by plotting the receiver operating characteristic curves. RESULTS: 3 samples of breast cancer survivors (N = 471, N = 132, N = 90) were included. Absolute values of correlations demonstrating convergent validity ranged from 0.21 to 0.82, ps &lt; 0.001, and were comparable to correlations with the full FACT-Cog 18 item perceived cognitive impairments&nbsp;(PCI) scale. ROC curve plots indicated a clinical cut off &lt; 34 for the combined sample. CONCLUSION: The 8-item PROMIS Cog demonstrated good convergent validity and internal reliability in breast cancer survivors, comparable to the 18-item FACT-Cog PCI. The PROMIS Cog 8a is a brief self-report measure that can be easily incorporated into cancer-related cognitive impairment research designs or used in clinical settings

Multimodal MRI examination of structural and functional brain changes in older women with breast cancer in the first year of antiestrogen hormonal therapy

Purpose: Cancer patients are concerned about treatment-related cognitive problems. We examined effects of antiestrogen hormonal therapy on brain imaging metrics in older women with breast cancer. Methods: Women aged 60 + treated with hormonal therapy only and matched non-cancer controls (n = 29/group) completed MRI and objective and self-reported cognitive assessment at pre-treatment/enrollment and 12 months later. Gray matter was examined using voxel-based morphometry (VBM), FreeSurfer, and brain age calculations. Functional MRI (fMRI) assessed working memory-related activation. Analyses examined cross-sectional and longitudinal differences and tested associations between brain metrics, cognition, and days on hormonal therapy. Results: The cancer group showed regional reductions over 12 months in frontal, temporal, and parietal gray matter on VBM, reduced FreeSurfer cortical thickness in prefrontal, parietal, and insular regions, and increased working memory-related fMRI activation in frontal, cingulate, and visual association cortex. Controls showed only reductions in fusiform gyrus on VBM and FreeSurfer temporal and parietal cortex thickness. Women with breast cancer showed higher estimated brain age and lower regional gray matter volume than controls at both time points. The cancer group showed a trend toward lower performance in attention, processing speed, and executive function at follow-up. There were no significant associations between brain imaging metrics and cognition or days on hormonal therapy. Conclusion: Older women with breast cancer showed brain changes in the first year of hormonal therapy. Increased brain activation during working memory processing may be a sign of functional compensation for treatment-related structural changes. This hypothesis should be tested in larger samples over longer time periods