Potential clinical impact of reporting breast arterial calcifications on screening mammograms in women without known coronary artery disease.

Cardiovascular disease remains a leading cause of death in women. 10-year likelihood for a cardiovascular event is determined by the American College of Cardiology Atherosclerotic Cardiovascular disease risk score calculator (ASVCD); however, this does not encompass risk factors unique to women. Breast arterial calcifications (BAC) detected on screening mammography may serve as a proxy for coronary atherosclerosis (CAC) in women. Our purpose was to investigate the correlation between BAC and CAC on imaging in women without a diagnosis of atherosclerosis to determine the potential clinical impact. Retrospective review was performed on a cohort of females evaluated by internists at our institution in 2019. Study patients had a screening mammogram within 1 year of a noncardiac chest CT. Clinical data were collected to determine ASCVD risk score. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of BAC in detecting CAC were determined. 222 women met inclusion criteria, ranging from 41 to 77 years of age, among which 25% (56/222) had BAC. 84% (47/56) of women with BAC had CAC on CT, yielding a sensitivity, specificity, PPV, and NPV of 51%, 93%, 84%, and 72%, respectively. Of the 47 patients who had both BAC and CAC, 66% had an unknown or low-to-borderline ASCVD score. Women with BACs have a high specificity for CAC. The reporting of BACs should prompt clinicians to risk stratify women for atherosclerotic disease. These women may otherwise be undetected by conventional risk calculators.

Whole-Body 12C Irradiation Transiently Decreases Mouse Hippocampal Dentate Gyrus Proliferation and Immature Neuron Number, but Does Not Change New Neuron Survival Rate.

High-charge and -energy (HZE) particles comprise space radiation and they pose a challenge to astronauts on deep space missions. While exposure to most HZE particles decreases neurogenesis in the hippocampus-a brain structure important in memory-prior work suggests that 12C does not. However, much about 12C's influence on neurogenesis remains unknown, including the time course of its impact on neurogenesis. To address this knowledge gap, male mice (9⁻11 weeks of age) were exposed to whole-body 12C irradiation 100 cGy (IRR; 1000 MeV/n; 8 kEV/µm) or Sham treatment. To birthdate dividing cells, mice received BrdU i.p. 22 h post-irradiation and brains were harvested 2 h (Short-Term) or three months (Long-Term) later for stereological analysis indices of dentate gyrus neurogenesis. For the Short-Term time point, IRR mice had fewer Ki67, BrdU, and doublecortin (DCX) immunoreactive (+) cells versus Sham mice, indicating decreased proliferation (Ki67, BrdU) and immature neurons (DCX). For the Long-Term time point, IRR and Sham mice had similar Ki67+ and DCX+ cell numbers, suggesting restoration of proliferation and immature neurons 3 months post-12C irradiation. IRR mice had fewer surviving BrdU+ cells versus Sham mice, suggesting decreased cell survival, but there was no difference in BrdU+ cell survival rate when compared within treatment and across time point. These data underscore the ability of neurogenesis in the mouse brain to recover from the detrimental effect of 12C exposure.

Multi-domain cognitive assessment of male mice shows space radiation is not harmful to high-level cognition and actually improves pattern separation.

Astronauts on interplanetary missions - such as to Mars - will be exposed to space radiation, a spectrum of highly-charged, fast-moving particles that includes 56Fe and 28Si. Earth-based preclinical studies show space radiation decreases rodent performance in low- and some high-level cognitive tasks. Given astronaut use of touchscreen platforms during training and space flight and given the ability of rodent touchscreen tasks to assess functional integrity of brain circuits and multiple cognitive domains in a non-aversive way, here we exposed 6-month-old C57BL/6J male mice to whole-body space radiation and subsequently assessed them on a touchscreen battery. Relative to Sham treatment, 56Fe irradiation did not overtly change performance on tasks of visual discrimination, reversal learning, rule-based, or object-spatial paired associates learning, suggesting preserved functional integrity of supporting brain circuits. Surprisingly, 56Fe irradiation improved performance on a dentate gyrus-reliant pattern separation task; irradiated mice learned faster and were more accurate than controls. Improved pattern separation performance did not appear to be touchscreen-, radiation particle-, or neurogenesis-dependent, as 56Fe and 28Si irradiation led to faster context discrimination in a non-touchscreen task and 56Fe decreased new dentate gyrus neurons relative to Sham. These data urge revisitation of the broadly-held view that space radiation is detrimental to cognition.