Comparing survival of older ovarian cancer patients treated with neoadjuvant chemotherapy versus primary cytoreductive surgery: Reducing bias through machine learning.

OBJECTIVE: To develop and evaluate a multidimensional comorbidity index (MCI) that identifies ovarian cancer patients at risk of early mortality more accurately than the Charlson Comorbidity Index (CCI) for use in health services research. METHODS: We utilized SEER-Medicare data to identify patients with stage IIIC and IV ovarian cancer, diagnosed in 2010-2015. We employed partial least squares regression, a supervised machine learning algorithm, to develop the MCI by extracting latent factors that optimally captured the variation in health insurance claims made in the year preceding cancer diagnosis, and 1-year mortality. We assessed the discrimination and calibration of the MCI for 1-year mortality and compared its performance to the commonly-used CCI. Finally, we evaluated the MCI's ability to reduce confounding in the association of neoadjuvant chemotherapy (NACT) and all-cause mortality. RESULTS: We included 4723 patients in the development cohort and 933 in the validation cohort. The MCI demonstrated good discrimination for 1-year mortality (c-index: 0.75, 95% CI: 0.72-0.79), while the CCI had poor discrimination (c-index: 0.59, 95% CI: 0.56-0.63). Calibration plots showed better agreement between predicted and observed 1-year mortality risk for the MCI compared with CCI. When comparing all-cause mortality between NACT with primary cytoreductive surgery, NACT was associated with a higher hazard of death (HR: 1.13, 95% CI: 1.04-1.23) after controlling for tumor characteristics, demographic factors, and the CCI. However, when controlling for the MCI instead of the CCI, there was no longer a significant difference (HR: 1.05, 95% CI: 0.96-1.14). CONCLUSIONS: The MCI outperformed the conventional CCI in predicting 1-year mortality, and reducing confounding due to differences in baseline health status in comparative effectiveness analysis of NACT versus primary surgery.

Levonorgestrel-releasing intrauterine device therapy versus oral progestin treatment for Reproductive-Aged patients with endometrial intraepithelial neoplasia: a systematic review and Meta-Analysis.

BACKGROUND: We conducted a systematic review and meta-analysis to examine outcomes of patients with endometrial intraepithelial neoplasia (EIN) treated with oral progestins or levonorgestrel-releasing intrauterine device (LNG-IUD). METHODS: We conducted a systematic review across five databases to examine outcomes of progestational treatment (oral progestins or LNG-IUD) for patients with EIN. The primary outcome was the best complete response (CR) rate within twelve months of primary progestational treatment. Sensitivity analyses were performed by removing studies with extreme effect sizes. Secondary outcomes included the pooled pregnancy rate. RESULTS: We identified 21 eligible studies, including 824 premenopausal patients with EIN, for our meta-analysis. Among these, 459 patients received oral progestin, while 365 patients received LNG-IUD as a primary progestational treatment. The pooled best CR proportion within 12 months was 82% (95% CI, 69-91) following oral progestin treatment, and 95% (95% CI, 81-99) following LNG-IUD treatment. After removing outlier studies, the pooled proportion was 86% (95% CI, 75-92) for the oral progestin group, and 96% (95% CI, 91-99) for the LNG-IUD group, with reduced heterogeneity. The pooled pregnancy rate was 50% (95% CI, 35-65) after oral progestin and 35% (95% CI, 23-49) after LNG-IUD treatment. CONCLUSIONS: This meta-analysis provides data on the effectiveness of oral progestins and LNG-IUD treatment within 12 months of treatment among premenopausal patients with EIN. Although based on small numbers, the rate of pregnancy after treatment is modest. These data may be beneficial for selecting progestational therapies that allow fertility preservation for patients with EIN.

Excess morbidity and mortality associated with underuse of estrogen replacement therapy in premenopausal women who undergo surgical menopause.

BACKGROUND: Contrary to clinical guidelines, there has been a decrease over time in estrogen therapy use in premenopausal women undergoing bilateral oophorectomy for benign indications. OBJECTIVE: This study aimed to estimate the excess morbidity and mortality associated with current patterns of estrogen therapy use in women who undergo bilateral oophorectomy with hysterectomy for benign indications. STUDY DESIGN: We developed 2 Bayesian sampling Markov state-transition models to estimate the excess disease incidence (incidence model) and mortality (mortality model). The starting cohort for both models were women who had undergone bilateral oophorectomy with hysterectomy for benign indications at the age of 45 to 49 years. The models tracked outcomes in 5-year intervals for 25 years. The incidence model estimated excess incidence of breast cancer, lung cancer, colorectal cancer, coronary heart disease, and stroke, whereas the mortality model estimated excess mortality due to breast cancer, lung cancer, coronary heart disease, and all-other-cause mortality. The models compared current rates of estrogen therapy use with optimal (100%) use and calculated the mean difference in each simulated outcome to determine excess disease incidence and death. RESULTS: By 25 years after bilateral oophorectomy with hysterectomy, there were an estimated 94 (95% confidence interval, -158 to -23) fewer colorectal cancer cases, 658 (95% confidence interval, 339-1025) more coronary heart disease cases, and 881 (95% confidence interval, 402-1483) more stroke cases. By 25 years after bilateral oophorectomy with hysterectomy, there were an estimated 189 (95% confidence interval, 59-387) more breast cancer deaths, 380 (95% confidence interval, 114-792) more coronary heart disease deaths, and 759 (95% confidence interval, 307-1527) more all-other-cause deaths. In sensitivity analyses where we defined estrogen therapy use as a duration of >2 years of use, these differences increased >2-fold. CONCLUSION: Underuse of estrogen therapy in premenopausal women who undergo oophorectomy is associated with substantial excess morbidity and mortality.

Estrogen replacement therapy and non-hormonal medication use among patients with uterine cancer.

OBJECTIVE: As the prognosis for endometrial cancer is excellent, management of the effects of estrogen deprivation has an important influence on quality of life. We examined the trends in the use of estrogen replacement therapy (ERT) and non-hormonal medications among patients with uterine cancer following surgery. METHODS: The MarketScan Database was used to identify patients 18-49 years who underwent hysterectomy plus oophorectomy and those aged 50-75 years who underwent hysterectomy between 2008 and 2020. ERT and non-hormonal treatments of menopause were identified preoperatively and postoperatively. After propensity score balancing, difference-in-differences (DID) analyses were performed to compare the pre-and-postoperative changes in ERT and non-hormonal medication use between groups. The trends in postoperative use of ERT were assessed and tested using Cochran-Armitage trend tests. RESULTS: A total of 19,700 patients with uterine cancer and 185,150 controls were identified. Overall, postoperative ERT use decreased for both age groups and for patients with and without uterine cancer. The DID in ERT use between those with uterine cancer and those with benign pathology after hysterectomy was -37.1% (95% CI, -40.5 to -33.6%) for patients 18-49 years of age and - 10.4% (95% CI, -10.9 to -9.9%) for those 50-75 years. The DID for non-hormonal medication use between those with uterine cancer and those with benign pathology after hysterectomy was 11.2% (95% CI, 7.8 to 14.7%) for younger patients and 3.4% (95% CI, 2.9 to 4.0%) for those 50-75 years. The postoperative new ERT use has been declining over time in patients with uterine cancer in those 18-49 years of age (P = .02) and those 50-75 years of age (P < .001). CONCLUSIONS: The use of ERT is uncommon and has declined over time in patients with uterine cancer. Conversely, non-hormonal medications are more commonly used among patients with uterine cancer.

Black-White differences in uterine cancer symptomatology and stage at diagnosis.

OBJECTIVE: To examine whether uterine cancer symptoms differ between Black and White patients and how this may influence their stage at diagnosis. METHODS: Using the Surveillance, Epidemiology and End Results-Medicare database, we identified 2328 Black and 21,774 White patients with uterine cancer in 2008-2017. Their symptoms in the 18 months before diagnosis were categorized as postmenopausal bleeding (PMB) alone, PMB together with other symptoms (e.g., abdominal/pelvic pain, bloating), non-PMB symptoms alone, or no symptoms. Stage at diagnosis was dichotomized as advanced (i.e., regional/distant) versus localized. The association between race and stage was analyzed using regression models incrementally adjusting for symptoms and other patient characteristics. RESULTS: A larger proportion of Black than White patients experienced PMB together with other symptoms (63.1% versus 58.0%) or experienced non-PMB symptoms alone (13.1% versus 9.4%) (p < 0.001). Black patients had a higher risk of advanced-stage diagnosis than White patients (45.0% versus 30.3%, unadjusted RR = 1.52, 95% CI: 1.44-1.59). Adjusting for Black-White differences in symptoms attenuated the RR to 1.46 (95% CI: 1.39-1.53). Compared to PMB symptoms alone, having additional non-PMB symptoms (RR = 1.21, 95% CI: 1.15-1.26) and having non-PMB symptoms alone (RR = 1.99, 95% CI: 1.88-2.10) were associated with increased risk of advanced-stage diagnosis. Further adjusting for histology and other patient characteristics reduced Black-White disparity in advanced-stage diagnosis to 1.08 (95% CI: 1.03-1.14) but symptoms remained significantly associated with stage at diagnosis. CONCLUSIONS: Having non-PMB symptoms was associated with more advanced stage at diagnosis. Non-PMB symptoms were more common among Black than White patients, which might hinder symptom recognition/evaluation.

Frontoparietal function and underlying structure reflect capacity for motor skill acquisition during healthy aging.

While capacity for motor skill acquisition changes with healthy aging, there has been little consideration of how age-related changes in brain function or baseline brain structure support motor skill acquisition. We examined: (1) age-dependent changes in functional reorganization related to frontoparietal regions during motor skill acquisition, and (2) whether capacity for motor skill acquisition relates to baseline white matter microstructure in frontoparietal tracts. Healthy older and younger adults engaged in 4 weeks of skilled motor practice. Resting-state functional connectivity (rsFC) assessed functional reorganization before and after practice. Diffusion tensor imaging indexed microstructure of a frontoparietal tract at baseline, generated by rsFC seeds. Motor skill acquisition was associated with decreases in rsFC in healthy older adults and increases in rsFC in healthy younger adults. Frontoparietal tract microstructure was lower in healthy older versus younger adults, yet it was negatively associated with rate of skill acquisition regardless of group. Findings indicate that age-dependent alterations in frontoparietal function and baseline structure of a frontoparietal tract reflect capacity for motor skill acquisition.

Systematic review and meta-analysis of disease clustering in multimorbidity: a study protocol.

INTRODUCTION: Multimorbidity is defined as the presence of two or more chronic diseases. Co-occurring diseases can have synergistic negative effects, and are associated with significant impacts on individual health outcomes and healthcare systems. However, the specific effects of diseases in combination will vary between different diseases. Identifying which diseases are most likely to co-occur in multimorbidity is an important step towards population health assessment and development of policies to prevent and manage multimorbidity more effectively and efficiently. The goal of this project is to conduct a systematic review and meta-analysis of studies of disease clustering in multimorbidity, in order to identify multimorbid disease clusters and test their stability. METHODS AND ANALYSIS: We will review data from studies of multimorbidity that have used data clustering methodologies to reveal patterns of disease co-occurrence. We propose a network-based meta-analytic approach to perform meta-clustering on a select list of chronic diseases that are identified as priorities for multimorbidity research. We will assess the stability of obtained disease clusters across the research literature to date, in order to evaluate the strength of evidence for specific disease patterns in multimorbidity. ETHICS AND DISSEMINATION: This study does not require ethics approval as the work is based on published research studies. The study findings will be published in a peer-reviewed journal and disseminated through conference presentations and meetings with knowledge users in health systems and public health spheres. PROSPERO REGISTRATION NUMBER: CRD42023411249.

White matter hyperintensities modify relationships between corticospinal tract damage and motor outcomes after stroke.

Motor outcomes after stroke relate to corticospinal tract (CST) damage. Concurrent damage from white matter hyperintensities (WMHs) might impact neurological capacity for recovery after CST injury. Here, we evaluated if WMHs modulate the relationship between CST damage and post-stroke motor impairment outcome. We included 223 individuals from the ENIGMA Stroke Recovery Working Group. CST damage was indexed with weighted CST lesion load (CST-LL). Mixed effects beta-regression models were fit to test the impact of CST-LL, WMH volume, and their interaction on motor impairment. WMH volume related to motor impairment above and beyond CST-LL (ß = 0.178, p = 0.022). We tested if relationships varied by WMH severity (mild vs. moderate-severe). In individuals with mild WMHs, motor impairment related to CST-LL (ß = 0.888, p < 0.001) with a CST-LL x WMH interaction (ß = -0.211, 0.026). In individuals with moderate-severe WMHs, motor impairment related to WMH volume (ß = 0.299, p = 0.044), but did not significantly relate to CST-LL or a CST-LL x WMH interaction. WMH-related damage may be under-recognised in stroke research as a factor contributing to variability in motor outcomes. Our findings emphasize the importance of brain structural reserve in motor outcomes after brain injury.

Quantifying the potential benefits of early detection for pancreatic cancer through a counterfactual simulation modeling analysis.

The benefits of cancer early detection depend on various factors, including cancer type, screening method performance, stage at diagnosis, and subsequent treatment. Although numerous studies have evaluated the effectiveness of screening interventions for identifying cancer at earlier stages, there is no quantitative analysis that studies the optimal early detection time interval that results in the greatest mortality benefit; such data could serve as a target and benchmark for cancer early detection strategies. In this study, we focus on pancreatic ductal adenocarcinoma (PDAC), a cancer known for its lack of early symptoms. Consequently, it is most often detected at late stages when the 5-year survival rate is only 3%. We developed a PDAC population model that simulates an individual patient's age and stage at diagnosis, while replicating overall US cancer incidence and mortality rates. The model includes "cancer sojourn time," serving as a proxy for the speed of cancer progression, with shorter times indicating rapid progression and longer times indicating slower progression. In our PDAC model, our hypothesis was that earlier cancer detection, potentially through a hypothetical screening intervention in the counterfactual analysis, would yield reduced mortality as compared to a no-screening group. We found that the benefits of early detection, such as increased life-years gained, are greater when the sojourn time is shorter, reaching their maximum when identification is made 4-6 years prior to clinical diagnosis (e.g., when a symptomatic diagnosis is made). However, when early detection occurs even earlier, for example 6-10 years prior to clinical diagnosis, the benefits significantly diminish for shorter sojourn time cancers, and level off for longer sojourn time cancers. Our study clarifies the potential benefits of PDAC early detection that explicitly incorporates individual patient heterogeneity in cancer progression and identifies quantitative benchmarks for future interventions.

Risk factors for developing both primary breast and primary ovarian cancer: A systematic review.

OBJECTIVE: Women with breast cancer have an increased risk of primary ovarian cancer (BR→OV), and women with ovarian cancer have an increased risk of primary breast cancer (OV→BR). This systematic review summarizes risk factors for developing BR→OV and OV→BR. METHODS: We searched PubMed and Embase until June 2022. RESULTS: We identified 23 articles meeting our inclusion criteria. Studies observed a lower risk of BR→OV for Black versus White women, alcohol consumption, radiotherapy and hormone therapy, BRCA2 versus BRCA1, and ER/PR positive versus negative breast tumors, and a higher risk with family history of breast/ovarian cancer, triple negative versus luminal breast cancer, and higher grade breast tumors. There was an increased risk of OV→BR with family history of cancer. CONCLUSIONS: Tumor characteristics, and genetic and familial factors are associated with risk of BR→OV and OV→BR. These results could aid clinicians in decision-making for breast and ovarian cancer patients, including risk-reducing strategies.

Improved processing speed and decreased functional connectivity in individuals with chronic stroke after paired exercise and motor training.

After stroke, impaired motor performance is linked to an increased demand for cognitive resources. Aerobic exercise improves cognitive function in neurologically intact populations and may be effective in altering cognitive function post-stroke. We sought to determine if high-intensity aerobic exercise paired with motor training in individuals with chronic stroke alters cognitive-motor function and functional connectivity between the dorsolateral prefrontal cortex (DLPFC), a key region for cognitive-motor processes, and the sensorimotor network. Twenty-five participants with chronic stroke were randomly assigned to exercise (n = 14; 66 ± 11 years; 4 females), or control (n = 11; 68 ± 8 years; 2 females) groups. Both groups performed 5-days of paretic upper limb motor training after either high-intensity aerobic exercise (3 intervals of 3 min each, total exercise duration of 23-min) or watching a documentary (control). Resting-state fMRI, and trail making test part A (TMT-A) and B were recorded pre- and post-intervention. Both groups showed implicit motor sequence learning (p < 0.001); there was no added benefit of exercise for implicit motor sequence learning (p = 0.738). The exercise group experienced greater overall cognitive-motor improvements measured with the TMT-A. Regardless of group, the changes in task score, and dwell time during TMT-A were correlated with a decrease in DLPFC-sensorimotor network functional connectivity (task score: p = 0.025; dwell time: p = 0.043), which is thought to reflect a reduction in the cognitive demand and increased automaticity. Aerobic exercise may improve cognitive-motor processing speed post-stroke.

Optimizing automated white matter hyperintensity segmentation in individuals with stroke.

White matter hyperintensities (WMHs) are a risk factor for stroke. Consequently, many individuals who suffer a stroke have comorbid WMHs. The impact of WMHs on stroke recovery is an active area of research. Automated WMH segmentation methods are often employed as they require minimal user input and reduce risk of rater bias; however, these automated methods have not been specifically validated for use in individuals with stroke. Here, we present methodological validation of automated WMH segmentation methods in individuals with stroke. We first optimized parameters for FSL's publicly available WMH segmentation software BIANCA in two independent (multi-site) datasets. Our optimized BIANCA protocol achieved good performance within each independent dataset, when the BIANCA model was trained and tested in the same dataset or trained on mixed-sample data. BIANCA segmentation failed when generalizing a trained model to a new testing dataset. We therefore contrasted BIANCA's performance with SAMSEG, an unsupervised WMH segmentation tool available through FreeSurfer. SAMSEG does not require prior WMH masks for model training and was more robust to handling multi-site data. However, SAMSEG performance was slightly lower than BIANCA when data from a single site were tested. This manuscript will serve as a guide for the development and utilization of WMH analysis pipelines for individuals with stroke.

Prescription of hormone replacement therapy among cervical cancer patients with treatment-induced premature menopause.

OBJECTIVE: To examine the utilization of hormone replacement therapy (HRT) among newly diagnosed cervical cancer patients who experienced premature menopause due to primary treatment. METHODS: The MarketScan Databases were used to identify newly diagnosed cervical cancer patients <50 years of age with premature menopause after hysterectomy with bilateral salpingo-oophorectomy (primary surgery) or primary external beam pelvic radiation (primary radiotherapy). We examined the cumulative utilization of HRT until 24 months after the loss of ovarian function. Fine-Gray subdistribution hazard models were developed to examine the factors associated with cumulative HRT use. The duration of HRT use was analyzed by Kaplan-Meier curves. RESULTS: A total of 1826 patients, including 352 (19.3%) who underwent primary surgery and 1474 (80.7%) who received primary radiotherapy, were identified. Overall, 39.0% of patients received HRT within 24 months of primary treatment. HRT was used in 49.4% of those who underwent primary surgery and in 36.6% of those who received primary radiotherapy (p<0.0001). The median duration of HRT use was 60 days among the entire cohort and was significantly shorter for the primary radiotherapy group than the primary surgery group (35 vs 90 days, p<0.0001). Primary radiotherapy, older age, residency in the Northeastern USA, and Black race were associated with a lower likelihood of HRT use. CONCLUSIONS: HRT was prescribed to less than half of patients with newly diagnosed cervical cancer under the age of 50 who experienced premature menopause due to primary treatment. Among those who used HRT the duration of use was short.

Multimorbidity resilience and health behaviors among older adults: A longitudinal study using the Canadian Longitudinal Study on Aging.

Objective: There has been a growing interest in examining why some individuals adapt and bounce back from multimorbidity (resilience) better than others. This paper investigates the positive role of protective health behaviors on multimorbidity resilience (MR) among older adults focusing on older persons with two or more concurrent chronic conditions, and separately for three multimorbidity chronic illness clusters. Methods: Using Baseline and Follow-up One data from the Comprehensive Cohort of the Canadian Longitudinal Study on Aging, we studied 10,628 participants aged 65 years and older who reported two or more of 27 chronic conditions, and three multimorbidity clusters: Cardiovascular/metabolic, Musculoskeletal, and Mental health. Associations between health behaviors and MR were evaluated using Linear Mixed Models, adjusting for socio-demographic, social/environmental, and illness context social determinants of health. Results: Among older adults with two or more illnesses, smoking, satisfaction with sleep, appetite, and skipping meals were associated with MR in the expected direction. Also, obesity (compared to normal weight) and skipping meals showed longitudinal interaction effects with survey wave. Most of the results were replicated for the physical multimorbidity clusters (Cardiovascular/metabolic and Musculoskeletal) compared to the full 2+ multimorbidity analyses; however, for the Mental health cluster, only satisfaction with sleep was supported as a lifestyle predictor of MR. Discussion: Several modifiable health behaviors identified in the broader health and aging literature are important in affecting levels of multimorbidity resilience in older age. These factors are important strength-based areas to target. Additionally, several social determinants of health are also supported and parallel research on multimorbidity risk. The effects of lifestyle factors for resilience among older adults is dependent on the type of multimorbidity measured. We conclude that the results have significant public health, program intervention, and clinical implications for healthy aging among persons coping with multimorbidity.

Exploring biomarkers of processing speed and executive function: The role of the anterior thalamic radiations.

INTRODUCTION: Processing speed and executive function are often impaired after stroke and in typical aging. However, there are no reliable neurological markers of these cognitive impairments. The trail making test (TMT) is a common index of processing speed and executive function. Here, we tested candidate MRI markers of TMT performance in a cohort of older adults and individuals with chronic stroke. METHODS: In 61 older adults and 32 individuals with chronic stroke, we indexed white matter structure with region-specific lesion load (of white matter hyperintensities (WMHs) and stroke lesions) and diffusion tensor imaging (DTI) from four regions related to TMT performance: the anterior thalamic radiations (ATR), superior longitudinal fasciculus (SLF), forceps minor, and cholinergic pathways. Regression modelling was used to identify the marker(s) that explained the most variance in TMT performance. RESULTS: DTI metrics of the ATR related to processing speed in both the older adult (TMT A: ß = -3.431, p < 0.001) and chronic stroke (TMT A: ß = 11.282, p < 0.001) groups. In the chronic stroke group executive function was best predicted by a combination of ATR and forceps minor DTI metrics (TMT B: adjustedR2 = 0.438, p < 0.001); no significant predictors of executive function (TMT B) emerged in the older adult group. No imaging metrics related to set shifting (TMT B-A). Regional DTI metrics predicted TMT performance above and beyond whole-brain stroke and WMH volumes and removing whole-brain lesion volumes improved model fits. CONCLUSIONS: In this comprehensive assessment of candidate imaging markers, we demonstrate an association between ATR microstructure and processing speed and executive function performance. Regional DTI metrics provided better predictors of cognitive performance than whole-brain lesion volumes or regional lesion load, emphasizing the importance of lesion location in understanding cognition. We propose ATR DTI metrics as novel candidate imaging biomarker of post-stroke cognitive impairment.

Adherence to the 2020 American Cancer Society Guideline for Cancer Prevention and risk of breast cancer for women at increased familial and genetic risk in the Breast Cancer Family Registry: an evaluation of the weight, physical activity, and alcohol consumption recommendations.

PURPOSE: The American Cancer Society (ACS) published an updated Guideline for Cancer Prevention (ACS Guideline) in 2020. Research suggests that adherence to the 2012 ACS Guideline might lower breast cancer risk, but there is limited evidence that this applies to women at increased familial and genetic risk of breast cancer. METHODS: Using the Breast Cancer Family Registry (BCFR), a cohort enriched for increased familial and genetic risk of breast cancer, we examined adherence to three 2020 ACS Guideline recommendations (weight management (body mass index), physical activity, and alcohol consumption) with breast cancer risk in 9615 women. We used Cox proportional hazard regression modeling to calculate hazard ratios (HRs) and 95% confidence intervals (CI) overall and stratified by BRCA1 and BRCA2 pathogenic variant status, family history of breast cancer, menopausal status, and estrogen receptor-positive (ER +) breast cancer. RESULTS: We observed 618 incident invasive or in situ breast cancers over a median 12.9 years. Compared with being adherent to none (n = 55 cancers), being adherent to any ACS recommendation (n = 563 cancers) was associated with a 27% lower breast cancer risk (HR = 0.73, 95% CI: 0.55-0.97). This was evident for women with a first-degree family history of breast cancer (HR = 0.68, 95% CI: 0.50-0.93), women without BRCA1 or BRCA2 pathogenic variants (HR = 0.71, 95% CI: 0.53-0.95), postmenopausal women (HR = 0.63, 95% CI: 0.44-0.89), and for risk of ER+ breast cancer (HR = 0.63, 95% CI: 0.40-0.98). DISCUSSION: Adherence to the 2020 ACS Guideline recommendations for BMI, physical activity, and alcohol consumption could reduce breast cancer risk for postmenopausal women and women at increased familial risk.

In vivo myelin imaging and tissue microstructure in white matter hyperintensities and perilesional white matter.

White matter hyperintensities negatively impact white matter structure and relate to cognitive decline in aging. Diffusion tensor imaging detects changes to white matter microstructure, both within the white matter hyperintensity and extending into surrounding (perilesional) normal-appearing white matter. However, diffusion tensor imaging markers are not specific to tissue components, complicating the interpretation of previous microstructural findings. Myelin water imaging is a novel imaging technique that provides specific markers of myelin content (myelin water fraction) and interstitial fluid (geometric mean T2). Here we combined diffusion tensor imaging and myelin water imaging to examine tissue characteristics in white matter hyperintensities and perilesional white matter in 80 individuals (47 older adults and 33 individuals with chronic stroke). To measure perilesional normal-appearing white matter, white matter hyperintensity masks were dilated in 2 mm segments up to 10 mm in distance from the white matter hyperintensity. Fractional anisotropy, mean diffusivity, myelin water fraction, and geometric mean T2 were extracted from white matter hyperintensities and perilesional white matter. We observed a spatial gradient of higher mean diffusivity and geometric mean T2, and lower fractional anisotropy, in the white matter hyperintensity and perilesional white matter. In the chronic stroke group, myelin water fraction was reduced in the white matter hyperintensity but did not show a spatial gradient in perilesional white matter. Across the entire sample, white matter metrics within the white matter hyperintensity related to whole-brain white matter hyperintensity volume; with increasing white matter hyperintensity volume there was increased mean diffusivity and geometric mean T2, and decreased myelin water fraction in the white matter hyperintensity. Normal-appearing white matter adjacent to white matter hyperintensities exhibits characteristics of a transitional stage between healthy white matter and white matter hyperintensities. This effect was observed in markers sensitive to interstitial fluid, but not in myelin water fraction, the specific marker of myelin concentration. Within the white matter hyperintensity, interstitial fluid was higher and myelin concentration was lower in individuals with more severe cerebrovascular disease. Our data suggests white matter hyperintensities have penumbra-like effects in perilesional white matter that specifically reflect increased interstitial fluid, with no changes to myelin concentration. In contrast, within the white matter hyperintensity there are varying levels of demyelination, which vary based on the severity of cerebrovascular disease. Diffusion tensor imaging and myelin imaging may be useful clinical markers to predict white matter hyperintensity formation, and to stage neuronal damage within white matter hyperintensities.

Observational Study of Neuroimaging Biomarkers of Severe Upper Limb Impairment After Stroke.

BACKGROUND AND OBJECTIVES: It is difficult to predict post-stroke outcome for people with severe motor impairment, as both clinical tests and corticospinal tract (CST) microstructure may not reliably indicate severe motor impairment. Here, we test whether imaging biomarkers beyond the CST relate to severe upper limb impairment post-stroke by evaluating white matter microstructure in the corpus callosum (CC). In an international, multisite hypothesis-generating observational study we determined if: a) CST asymmetry index can differentiate between individuals with mild-moderate and severe upper limb impairment; and b) CC biomarkers relate to upper limb impairment within individuals with severe impairment post-stroke. We hypothesised that CST asymmetry index would differentiate between mild-moderate and severe impairment, but CC microstructure would relate to motor outcome for individuals with severe upper limb impairment. METHODS: Seven cohorts with individual diffusion imaging and motor impairment (Fugl Meyer-Upper Limb) data were pooled. Hand-drawn regions-of-interest were used to seed probabilistic tractography for CST (ipsilesional/contralesional) and CC (prefrontal/premotor/motor/sensory/posterior) tracts. Our main imaging measure was mean fractional anisotropy. Linear mixed-effect regression explored relationships between candidate biomarkers and motor impairment, controlling for observations nested within cohorts, as well as age, sex, time post-stroke and lesion volume. RESULTS: Data from 110 individuals (30 mild-moderate, 80 with severe motor impairment) were included. In the full sample, greater CST asymmetry index (i.e., lower fractional anisotropy in the ipsilesional hemisphere, p<.001) and larger lesion volume (p=.139) were negatively related to impairment. In the severe subgroup, CST asymmetry index was not reliably associated with impairment across models. Instead, lesion volume and CC microstructure explained impairment in the severe group beyond CST asymmetry index (p's<.010). CONCLUSIONS: Within a large cohort of individuals with severe upper limb impairment, CC microstructure related to motor outcome post-stroke. Our findings demonstrate that CST microstructure does relate to upper limb outcome across the full range of motor impairment but was not reliably associated within the severe subgroup. Therefore, CC microstructure may provide a promising biomarker for severe upper limb outcome post-stroke, which may advance our ability to predict recovery in people with severe motor impairment after stroke.

Microbiome Profiles of Nebulizers in Hospital Use.

Background: Nebulizers are used to provide treatment to respiratory patients. Concerns over nosocomial infection risks from contaminated nebulizers raise the critical need to identify all microbial populations in nebulizers used by patients. However, conventional culture-dependent techniques are inadequate with the ability to identify specific microbial populations only. Therefore, the aims of this study were to acquire complete profiles of microbiomes in nebulizers used by in-patients with culture-independent high-throughput sequencing and identify sources of microbial contaminants for the development of effective practices to reduce microbial contamination in nebulizer devices. Methods: This study was conducted at the University of Tennessee Medical Center in Knoxville, TN. Nebulizers were collected between May 2018 and October 2018 from inpatients admitted to the floors for pneumonia or chronic obstructive pulmonary disease exacerbations. Nebulizers were sampled for 16S rRNA gene-based amplicon sequencing to profile nebulizer microbiomes and perform phylogenetic analysis. A Bayesian community-wide culture-independent microbial source tracking technique was used to quantify the contribution of human-associated microbiota as potential sources of nebulizer contamination. Results: Culture-independent sequencing detected diverse microbial populations in nebulizers, represented by 18 abundant genera. Stenotrophomonas was identified as the most abundant genus, accounting for 12.4% of the nebulizer microbiome, followed by Rhizobium, Staphylococcus, Streptococcus, and Ralstonia. Phylogenetic analysis revealed the presence of multiple phylotypes with close relationship to potential pathogens. Contributing up to 15% to nebulizer microbiomes, human-associated microbiota was not identified as the primary sources of nebulizer contamination. Conclusion: Culture-independent sequencing was demonstrated to be capable of acquiring comprehensive profiles of microbiomes in nebulizers used by in-patients. Phylogenetic analysis identified differences in pathogenicity between closely related phylotypes. Microbiome profile-enabled community-wide culture-independent microbial source tracking suggested greater importance of environmental sources than human sources as contributors to nebulizer microbiomes, providing important insight for the development of effective strategies for the monitoring and control of nebulizer devices to mitigate infection risks in the hospital.

Acute High-Intensity Interval Exercise Modulates Corticospinal Excitability in Older Adults.

INTRODUCTION: Acute exercise can modulate the excitability of the nonexercised upper limb representation in the primary motor cortex (M1). Measures of M1 excitability using transcranial magnetic stimulation (TMS) are modulated after various forms of acute exercise in young adults, including high-intensity interval training (HIIT). However, the impact of HIIT on M1 excitability in older adults is currently unknown. Therefore, the purpose of the current study was to investigate the effects of lower limb cycling HIIT on bilateral upper limb M1 excitability in older adults. METHODS: We assessed the impact of acute lower limb HIIT or rest on bilateral corticospinal excitability, intracortical inhibition and facilitation, and interhemispheric inhibition of the nonexercised upper limb muscle in healthy older adults (mean age 66 ± 8 yr). We used single and paired-pulse TMS to assess motor evoked potentials, short-interval intracortical inhibition, intracortical facilitation, and the ipsilateral silent period. Two groups of healthy older adults completed either HIIT exercise or seated rest for 23 min, with TMS measures performed before (T0), immediately after (T1), and 30 min after (T2) HIIT/rest. RESULTS: Motor evoked potentials were significantly increased after HIIT exercise at T2 compared with T0 in the dominant upper limb. Contrary to our hypothesis, we did not find any significant change in short-interval intracortical inhibition, intracortical facilitation, or ipsilateral silent period after HIIT. CONCLUSIONS: Our findings demonstrate that corticospinal excitability of the nonexercised upper limb is increased after HIIT in healthy older adults. Our results indicate that acute HIIT exercise impacts corticospinal excitability in older adults, without affecting intracortical or interhemispheric circuitry. These findings have implications for the development of exercise strategies to potentiate neuroplasticity in healthy older and clinical populations.