Chemotherapy-induced amenorrhea: a prospective study of brain activation changes and neurocognitive correlates

Chemotherapy-induced amenorrhea (CIA) often occurs in pre- and peri-menopausal BC patients, and while cancer/chemotherapy and abrupt estrogen loss have separately been shown to affect cognition and brain function, studies of the cognitive effects of CIA are equivocal, and its effects on brain function are unknown. Functional MRI (fMRI) during a working memory task was used to prospectively assess the pattern of brain activation and deactivation prior to and one month after chemotherapy in BC patients who experienced CIA (n=9), post-menopausal BC patients undergoing chemotherapy (n=9), and pre- and post-menopausal healthy controls (n=6 each). Neurocognitive testing was also performed at both time points. Repeated measures general linear models were used to assess statistical significance, and age was a covariate in all analyses. We observed a group-by-time interaction in the combined magnitudes of brain activation and deactivation (p = 0.006): the CIA group increased in magnitude from baseline to post-treatment while other groups maintained similar levels over time. Further, the change in brain activity magnitude in CIA was strongly correlated with change in processing speed neurocognitive testing score (r=0.837 p=0.005), suggesting this increase in brain activity reflects effective cognitive compensation. Our results demonstrate prospectively that the pattern of change in brain activity from pre- to post-chemotherapy varies according to pre-treatment menopausal status. Cognitive correlates add to the potential clinical significance of these findings. These findings have implications for risk appraisal and development of prevention or treatment strategies for cognitive changes in CIA

Longitudinal assessment of cognitive changes associated with adjuvant treatment for breast cancer: the impact of APOE and smoking

PURPOSE: This study examined the association of post-treatment changes in cognitive performance, apolipoprotein E (APOE), and smoking in breast cancer patients treated with adjuvant therapy. PARTICIPANTS AND METHODS: Breast cancer patients treated with chemotherapy (N = 55, age = 51.9 ± 7.1, education = 15.7 ± 2.6) were evaluated with a battery of neuropsychological tests prior to chemotherapy and at 1, 6, and 18 months post-chemotherapy. Matched groups of breast cancer patients not exposed to chemotherapy (N = 68, age = 56.8 ± 8.3, education = 14.8 ± 2.2) and healthy controls (N = 43, age = 53.0 ± 10.1, education = 15.2 ± 2.6) were evaluated at similar intervals. APOE epsilon 4 carrier status (APOE4+) and smoking history were also evaluated. RESULTS: The detrimental effect of APOE4+ genotype on post-treatment cognitive functioning was moderated by smoking history, that is, patients without a smoking history had significantly lower performance on measures of processing speed and working memory compared with those with a smoking history and healthy controls. Exploratory analyses revealed that APOE4+ patients without a smoking history who were exposed to chemotherapy showed a decline in performance in processing speed, compared with patients with a smoking history. A similar but less pronounced pattern was seen in the no chemotherapy group (primarily endocrine treatment). For working memory, the APOE4+ by smoking interaction was observed in the no chemotherapy group only. CONCLUSIONS: The association between APOE status, breast cancer treatment, and cognitive functioning was moderated by smoking history suggesting that both chemotherapy and endocrine therapy interact with APOE status and smoking to influence cognition. A putative mechanism is that smoking corrects a deficit in nicotinic receptor functioning and dopamine levels in APOE4+ individuals

Reliable change in neuropsychological assessment of breast cancer survivors

BACKGROUND: The purpose of this study was to enhance the current understanding and interpretation of longitudinal change on tests of neurocognitive function in individuals with cancer. Scores on standard neuropsychological instruments may be impacted by practice effects and other random forms of error. METHODS: The current study assessed the test-retest reliability of several tests and overarching cognitive domains comprising a neurocognitive battery typical of those used for research and clinical evaluation using relevant time frames. Practice effect-adjusted reliable change confidence intervals for test-retest difference scores based on a sample of patient-matched healthy controls are provided. RESULTS: By applying reliable change confidence intervals to scores from two samples of breast cancer patients at post-treatment follow-up assessment, meaningful levels of detectable change in cognitive functioning in breast cancer survivors were ascertained and indicate that standardized neuropsychological instruments may be subject to limitations in detection of subtle cognitive dysfunction over clinically relevant intervals, especially in patient samples with average to above average range baseline functioning. CONCLUSIONS: These results are discussed in relation to reported prevalence of cognitive change in breast cancer patients along with recommendations for study designs that enhance detection of treatment effects

Surface-controlled reversal of the selectivity of halogen bonds

Intermolecular halogen bonds are ideally suited for designing new molecular assemblies because of their strong directionality and the possibility of tuning the interactions by using different types of halogens or molecular moieties. Due to these unique properties of the halogen bonds, numerous areas of application have recently been identified and are still emerging. Here, we present an approach for controlling the 2D self-assembly process of organic molecules by adsorption to reactive vs. inert metal surfaces. Therewith, the order of halogen bond strengths that is known from gas phase or liquids can be reversed. Our approach relies on adjusting the molecular charge distribution, i.e., the σ-hole, by molecule-substrate interactions. The polarizability of the halogen and the reactiveness of the metal substrate are serving as control parameters. Our results establish the surface as a control knob for tuning molecular assemblies by reversing the selectivity of bonding sites, which is interesting for future applications

Positive affective functioning in anhedonic individuals' daily life:Anything but Flat and Blunted

Background Anhedonia, the decreased interest and pleasure, is often described as 'flat' or 'blunted' positive affect (PA). Yet, little is known about PA functioning in anhedonic individuals' daily lives. The current study investigates PA reactivity to pleasurable experiences in anhedonia together with its relevant temporal dynamics (i.e., variability, instability, and inertia), and expands current knowledge by exploring the role of arousal therein. Methods: Using the Experience Sampling Method (ESM), we collected 90 assessments of real-life PA experiences across 30 days in 18-24 year old individuals with anhedonia (N = 69) and without anhedonia (N = 69). Results: Multilevel analyses showed that anhedonia was associated with less intense pleasure experience, and lower levels of PA. Contrary to predictions from laboratory research and depression theory, individuals with anhedonia showed more variability and less stability in PA, and no signs of blunted PA reactivity. In fact, when exploring high and low arousal PA, individuals with anhedonia showed a slightly stronger reactivity to pleasurable experiences in high-arousal PA but not low-arousal PA. Limitations: We did not control for previous pleasure experiences and, instead of the last positive event, accumulation of positive events may have determined the change in high-arousal PA. Conclusions: Individuals with anhedonia are likely less 'flat' or 'blunted' than generally thought. Although replication is warranted, impairments in high-arousal positive emotions may be of particular interest in the clinical treatment of anhedonia

Cognitive effects of cancer and its treatments at the intersection of aging: what do we know; what do we need to know?

There is a fairly consistent, albeit non-universal body of research documenting cognitive declines after cancer and its treatments. While few of these studies have included subjects aged 65 years and older, it is logical to expect that older patients are at risk of cognitive decline. Here, we use breast cancer as an exemplar disease for inquiry into the intersection of aging and cognitive effects of cancer and its therapies. There are a striking number of common underlying potential biological risks and pathways for the development of cancer, cancer-related cognitive declines, and aging processes, including the development of a frail phenotype. Candidate shared pathways include changes in hormonal milieu, inflammation, oxidative stress, DNA damage and compromised DNA repair, genetic susceptibility, decreased brain blood flow or disruption of the blood-brain barrier, direct neurotoxicity, decreased telomere length, and cell senescence. There also are similar structure and functional changes seen in brain imaging studies of cancer patients and those seen with "normal" aging and Alzheimer's disease. Disentangling the role of these overlapping processes is difficult since they require aged animal models and large samples of older human subjects. From what we do know, frailty and its low cognitive reserve seem to be a clinically useful marker of risk for cognitive decline after cancer and its treatments. This and other results from this review suggest the value of geriatric assessments to identify older patients at the highest risk of cognitive decline. Further research is needed to understand the interactions between aging, genetic predisposition, lifestyle factors, and frailty phenotypes to best identify the subgroups of older patients at greatest risk for decline and to develop behavioral and pharmacological interventions targeting this group. We recommend that basic science and population trials be developed specifically for older hosts with intermediate endpoints of relevance to this group, including cognitive function and trajectories of frailty. Clinicians and their older patients can advance the field by active encouragement of and participation in research designed to improve the care and outcomes of the growing population of older cancer patients

Branch-Specific Microtubule Destabilization Mediates Axon Branch Loss during Neuromuscular Synapse Elimination

Developmental axon remodeling is characterized by the selective removal of branches from axon arbors. The mechanisms that underlie such branch loss are largely unknown. Additionally, how neuronal resources are specifically assigned to the branches of remodeling arbors is not understood. Here we show that axon branch loss at the developing mouse neuromuscular junction is mediated by branch-specific microtubule severing, which results in local disassembly of the microtubule cytoskeleton and loss of axonal transport in branches that will subsequently dismantle. Accordingly, pharmacological microtubule stabilization delays neuromuscular synapse elimination. This branch-specific disassembly of the cytoskeleton appears to be mediated by the microtubule-severing enzyme spastin, which is dysfunctional in some forms of upper motor neuron disease. Our results demonstrate a physiological role for a neurodegeneration-associated modulator of the cytoskeleton, reveal unexpected cell biology of branch-specific axon plasticity and underscore the mechanistic similarities of axon loss in development and disease

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

Large-scale replication study reveals a limit on probabilistic prediction in language comprehension

Do people routinely pre-activate the meaning and even the phonological form of upcoming words? The most acclaimed evidence for phonological prediction comes from a 2005 Nature Neuroscience publication by DeLong, Urbach and Kutas, who observed a graded modulation of electrical brain potentials (N400) to nouns and preceding articles by the probability that people use a word to continue the sentence fragment (‘cloze’). In our direct replication study spanning 9 laboratories (N=334), pre-registered replication-analyses and exploratory Bayes factor analyses successfully replicated the noun-results but, crucially, not the article-results. Pre-registered single-trial analyses also yielded a statistically significant effect for the nouns but not the articles. Exploratory Bayesian single-trial analyses showed that the article-effect may be non-zero but is likely far smaller than originally reported and too small to observe without very large sample sizes. Our results do not support the view that readers routinely pre-activate the phonological form of predictable words.Additional co-authors: Simon Busch-Moreno, Xiao Fu, Jyrki Tuomainen, Eugenia Kulakova, E Matthew Husband, Zdenko Kohút, Shirley-Ann Rueschemeyer, Falk Huetti

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal