Construct validation of NIH Toolbox Cognition Battery premorbid cognitive functioning scores in Black and White older Americans with and without mild cognitive impairment

OBJECTIVE

Valid estimates of premorbid cognitive functioning (PMIQ) are crucial for the assessment of older adults at risk for Alzheimer's disease. We investigated the relationship between the NIH Toolbox-Cognition Battery's (NIHTB-CB) Oral Reading Recognition (ORR) subtest and Wechsler Test of Adult Reading scores (WTAR, convergent validity). We also compared ORR to NIHTB-CB Flanker scores, where null relationships were expected (discriminant validity).

METHODS

The WTAR and NIHTB-CB were administered to 130 cognitively normal (CN) and 113 participants with mild cognitive impairment (MCI). Participants were community-dwelling, older Black and White adults, ages 55-88 years. Data analysis used uncorrected standard scores and Bayesian bivariate correlations. Supplemental materials include intraclass correlations.

RESULTS

ORR and WTAR scores were strongly positively associated, while ORR and Flanker scores were unrelated. This pattern held when restricting analyses to the two cognitive status groups, the two racial groups, and the four race-by-diagnosis subgroups.

CONCLUSION

The findings demonstrate convergent and discriminant validity and support NIHTB-CB ORR scores as valid estimates of scores on a PMIQ measure in older Black and White adults with and without MCI.

Direct Heterocycle C-H Alkenylation via Dual Catalysis Using a Palladacycle Precatalyst: Multifactor Optimization and Scope Exploration Enabled by High-Throughput Experimentation

One of the major challenges in developing catalytic methods for C-C bond formation is the identification of generally applicable reaction conditions, particularly if multiple substrate structural classes are involved. Pd-catalyzed direct arylation reactions are powerful transformations that enable direct functionalization of C-H bonds; however, the corresponding direct alkenylation reactions, using vinyl (pseudo) halide electrophiles, are less well developed. Inspired by process development efforts toward GSK3368715, an investigational active pharmaceutical ingredient, we report that a Pd(II) palladacycle derived from tri-tert-butylphosphine and Pd(OAc)2 is an effective single-component precatalyst for a variety of direct alkenylation reactions. High-throughput experimentation identified optimal solvent/base combinations for a variety of HetAr-H substrate classes undergoing C-H activation without the need for cocatalysts or stoichiometric silver bases (e.g., Ag2CO3). We propose this reaction proceeds via a dual cooperative catalytic mechanism, where in situ-generated Pd(0) supports a canonical Pd(0)/(II) cross-coupling cycle and the palladacycle effects C-H activation via CMD in a redox-neutral cycle. In all, 192 substrate combinations were tested with a hit rate of approximately 40% and 24 isolated examples. Importantly, this method was applied to prepare a key intermediate in the synthesis of GSK3368715 on multigram scale.

Cross-cultural evaluation of learning and memory using a consonant-vowel-consonant trigram list

OBJECTIVE

Word list-learning tasks are commonly used to evaluate auditory-verbal learning and memory. However, different frequencies of word usage, subtle meaning nuances, unique word phonology, and different preexisting associations among words make translation across languages difficult. We administered lists of consonant-vowel-consonant (CVC) nonword trigrams to independent American and Italian young adult samples. We evaluated whether an auditory list-learning task using CVC nonword trigrams instead of words could be applied cross-culturally to evaluate similar learning and associative memory processes.

PARTICIPANTS AND METHODS

Seventy-five native English-speaking (USA) and 104 native Italian-speaking (Italy) university students were administered 15-item lists of CVC trigrams using the Rey Auditory Verbal Learning Test paradigm with five study-test trials, an interference trial, and short- and long-term delayed recall. Bayesian t tests and mixed-design ANOVAs contrasted the primary learning indexes across the two samples and biological sex.

RESULTS

Performance was comparable between nationalities on all primary memory indices except the interference trial (List B), where the Italian group recalled approximately one item more than the American sample. For both nationalities, recall increased across the five learning trials and declined significantly on the postinterference trial, demonstrating susceptibility to retroactive interference. No effects of sex, age, vocabulary, or depressive symptoms were observed.

CONCLUSIONS

Using lists of unfamiliar nonword CVC trigrams, Italian and American younger adults showed a similar performance pattern across immediate and delayed recall trials. Whereas word list-learning performance is typically affected by cultural, demographic, mood, and cognitive factors, this trigram list-learning task does not show such effects, demonstrating its utility for cross-cultural memory assessment.

B - 79 Response Time to Derived Relations Is Related to Episodic Memory Performance

OBJECTIVE

After two stimulus pairs with a common stimulus are presented, healthy adults readily derive multiple indirect associations between each stimulus without explicit training. Factors related to this ability to derive new associations are relatively unstudied. We investigated the effects of sex and episodic memory performance on response times (RT) for different stimulus types (letters versus symbols) during trained and derived relational responding.

METHOD

Ninety-four cognitively healthy young adults were administered a relational responding (RR) task and the Hopkins Verbal Learning Test-Revised (HVLT-R) remotely via videoconferencing. In the RR task, two associations were directly trained in a single learning trial (A → B; A → C). Four other associations can be derived (B → A; C → A; B → C; C → B). Moderated multiple regressions examined main and interaction effects of sex and HVLT-R performance on correct RTs for trained and derived relations between letters and symbols, separately.

RESULTS

Higher HVLT-R immediate and delayed recall scores were associated with faster RTs for all derived, but not trained, relations in the letter (p = 0.001-0.022) and symbol (p = 0.006-0.043) conditions. There was no main effect of sex, but significant sex by HVLT-R interactions were observed for several derived relations in the symbol (p = 0.032-0.044) and letter conditions (p = 0.035). Only males showed a significant RR-HVLT-R association.

CONCLUSIONS

After a single presentation of two stimulus pairs, participants learned the two trained associations and independently derived four new, untrained stimulus relations. Better HVLT-R performance predicted faster RT uniquely for derived relations between letters/symbols. This relationship was more robust in males. Future research should evaluate the effectiveness of RR-based interventions for memory rehabilitation.

Metacognition in Community-Dwelling Older Black and African American Adults During the COVID-19 Pandemic

BACKGROUND

Cognitive assessment of older adults typically includes symptom reports and objective evaluations. However, there is often poor agreement between these measures. Cultural norms, stress, and anxiety may also influence cognitive self-appraisal and performance. Little research describes how other factors affect the self-report/objective test discrepancies noted in the literature.

OBJECTIVE

This study investigated whether the disparity between subjective cognitive concerns and objective cognitive performance is related to measures of anxiety and stress in older Black and African American adults.

METHODS

Telephone screenings were administered to 206 older adults (ages 64-94) during the first year of the pandemic. Demographic data, objective memory (Telephone Interview for Cognitive Status [TICS-m]), an adaptation of the subjective memory measure, the Cognitive Change Questionnaire, emphasizing executive functioning in everyday life [CCQ-e]), Generalized Anxiety Disorder-7 (GAD-7), and Perceived Stress Scale-4 (PSS4) were measured. Metacognition Discrepancy Index (MDI) was calculated from the standardized residual after regressing TICS-m on CCQ-e scores to quantify the discrepancy between cognitive self-appraisal and objective cognitive functioning.

RESULTS

Neither GAD-7 nor PSS-4 moderated the relationship between TICS-m and CCQ-e, and TICS-m scores weakly predicted subjective CCQ-e scores (F(1, 197)=4.37, p = 0.038, R2 = 0.022). The MDI correlated with stress and anxiety (rs = 0.294, 0.396, ps < 0.001).

CONCLUSION

Discrepancies exist between objectively measured and self-evaluated cognition. Elevations in stress and anxiety are associated with greater overestimation of cognitive difficulties relative to objective performance. Pandemic-related stressors may have worsened anxiety and diminished self-appraisal of cognitive abilities for some individuals, while others may remain reluctant to acknowledge impairments. Social and emotional factors are meaningful considerations in assessing cognitive difficulties.

DOES NEGATIVE AFFECT MODERATE THE RELATIONSHIP BETWEEN SUBJECTIVE COGNITIVE CONCERNS AND OBJECTIVE FUNCTIONING?

The onset of Alzheimer’s disease can be insidious, slowly affecting an individual’s cognitive abilities. Previous research demonstrated that informant-reported cognitive decline was associated with significantly worse baseline and longitudinal cognitive performance than was a participant’s subjective perceptions of decline. What remains unclear is how negative affect (i.e., depressive symptoms) could moderate the relation between objective cognitive performance and subjectively perceived cognitive concerns (participant vs. informant). Using the National Alzheimer’s Coordinating Center (NACC) database, we performed moderated multiple regressions to test whether Geriatric Depression Scale (GDS) score showed different relationships with cognitive measures (animal/vegetable fluency, digit span, Boston Naming Test, digit-symbol coding (DSC), Wechsler Memory Scale Logical Memory, Trail-Making Test, and Mini-Mental State Examination) for participant- and informant-reported cognitive decline (yes/no). Participants were aged ≥65 years and were cognitively healthy at baseline. Informants lived with the participant or visited the participant weekly (N = 9,354). Participant-reported cognitive concern interacted significantly (p<.05) with negative affect only for animal fluency while informant-reported cognitive concern interacted significantly with DSC. Depressive symptoms were associated more strongly with cognitive performance for participants who did not report a subjective cognitive decline compared to those who did report a subjective cognitive decline. Participant age showed significant negative relationships with all measures while GDS score showed significant negative relationships with all measures except immediate Logical Memory recall, regardless of decline status. In conclusion, negative affect generally did not moderate the relationship between participant- or informant-reported cognitive concerns and objective cognitive functioning except for animal category fluency and DSC.

METACOGNITION AND EMOTIONS IN OLDER AFRICAN AMERICAN ADULTS

Older adults in the earliest stages of cognitive decline often present with subjective cognitive complaints which may not be fully reflected in objective measures of cognition. Previous research suggests that a relationship exists between negative emotions, stress and metacognition, but these relationships have not yet been examined in the context of COVID-19. The purpose of this study was to examine the role of stress and emotions in perceived cognition in the context of the COVID-19 pandemic. Telephone screenings were administered to 206 older African Americans (aged 64–94 years). Objective cognition (Telephone Interview for Cognitive Status [TICS]), subjective cognition (Cognitive Change Questionnaire [CCQ]), perceived stress scale 4 (PSS-4), and survey questions about affective responses to COVID-19 experiences were measured. Objective TICS scores predicted subjective CCQ executive function scores (F(1, 197)=4.37, p=.038, R2=.022). Discrepancy scores were calculated as the standardized residual variance between objective and subjective measures. Survey items describing emotional states were summarized with emodiversity scores following Quoidbach and colleagues’ (2014) formula. Discrepancy scores were correlated with perceived stress, as well as global and negative emodiversity (Spearman r=.294, .279, .318, p&lt;.001). In conclusion, we have shown that objective and subjective measures of cognition are related, but discrepancies exist between objectively-measured and self-perceived cognition. Increased stress and greater negative emotions are associated with greater overestimation of cognitive difficulties relative to one’s objective level of cognition. As stress and negative emotions have increased for many during the pandemic, individuals may also have depreciated their self-appraisal of cognitive abilities in the present climate.

LONGITUDINAL EFFECTS OF HYPERTENSION ON COGNITIVE PERFORMANCE IN OLDER ADULTS

Hypertension impacts many older adults, but it is still not clear whether it has a negative effect on cognitive performance in older adults. The purpose of this study was to assess the longitudinal effect of hypertension on cognition in older adults (Mage=75.6 years, SD=8.3). Participants came from the National Alzheimer’s Coordinating Center database. The cognitive assessment included the MoCA, Digit Span, Trail-Making Test A and B, WAIS-R Digit Symbol, Category Fluency, and Letter Fluency. Linear mixed effects modeling examined the random and fixed effects of clinician-assessed hypertension, months since first study visit, sex, age, and the interaction between hypertension and time since first visit on cognitive performance across five annual study visits. Results showed that hypertension had a significant main effect on Category Fluency, Trails B, Letter Fluency, and Digit Span–Forward and Backward. However, effect sizes were quite small (ηp2 range: 3.93x10-4 – 1.73x10-3). Main effects of age and months since first visit were significant predictors of all cognitive measures, such that older age was associated with worse cognitive performance and more months since the first visit was associated with better cognitive performance. This positive association is perhaps suggestive of practice effects across study visits. A significant interaction between hypertension and months since first visit for Category Fluency and Trails B showed that hypertensives and non-hypertensives performed differently at the initial visit but similarly by the last visit. However, effect sizes were small (ηp2 range: 3.86–9.64x10-4). These results suggest hypertension effects on cognition in older adults are minimal.

Neuroimaging Markers for Determining Former American Football Players at Risk for Alzheimer's Disease

NFL players, by virtue of their exposure to traumatic brain injury (TBI), are at higher risk of developing dementia and Alzheimer's disease (AD) than the general population. Early recognition and intervention before the onset of clinical symptoms could potentially avert/delay the long-term consequences of these diseases. Given that AD is thought to have a long pre-clinical incubation period, the aim of the current research was to determine whether former NFL players show evidence of incipient dementia in their structural imaging before diagnosis of AD. To identify neuroimaging markers of AD, against which former NFL players would be compared, we conducted a whole-brain volumetric analysis using a cohort of AD patients (ADNI clinical database) to produce a set of brain regions demonstrating sensitivity to early AD pathology (i.e., the “AD fingerprint”). A group of 46 former NFL players' brain magnetic resonance images were then interrogated using the AD fingerprint, that is, the former NFL subjects were compared volumetrically to AD patients using a T1-weighted magnetization-prepared rapid gradient echo sequence. The FreeSurfer image analysis suite (version 6.0) was used to obtain volumetric and cortical thickness data. The Automated Neuropsychological Assessment Metric-Version 4 was used to assess current cognitive functioning. A total of 55 brain regions demonstrated significant atrophy or ex vacuo dilatation bilaterally in AD patients versus controls. Of the 46 former NFL players, 41% demonstrated a greater than expected number of atrophied/dilated AD regions compared with age-matched controls, presumably reflecting AD pathology.

Cognitive Reserve and Cognitive Functioning among Oldest Old Adults: Findings from the Georgia Centenarian Study

OBJECTIVES

Living a long life does not guarantee the maintenance of optimal cognitive functioning; however, similar to older adults in general, cognitive reserve may also protect oldest-old adults from cognitive decline. The purpose of this study was to assess cognitive reserve among centenarians and octogenarians and to evaluate a process model of cognitive reserve.

METHODS

A total of 321 centenarians and octogenarians from the Georgia Centenarian Study were included in this study. Cognitive reserve components included level of education, occupational responsibility, current social engagement, past engaged lifestyle, and activity. Cognitive functioning was measured with the Mini-Mental Status Examination.

RESULTS

Structural equation modeling was computed, and the overall model fit well, χ2 (df = 3) = 5.02, p = .17; CFI = .99, RMSEA = .05. Education is directly and indirectly related to cognitive functioning through occupational responsibility and past engaged lifestyle. Current social engagement is related to cognitive functioning directly and indirectly through current activities. The four direct predictors (i.e., education, current social engagement, current activity, and past engaged lifestyle) explained 35% of the variance in cognitive functioning.

CONCLUSION

The results provide important information for cognitive reserve theories with implications for interventions that build cognitive reserve.

Forward-focused coping predicts better mental health outcomes in mid- to late-life during the COVID-19 pandemic

Objectives: Psychosocial stressors associated with the COVID-19 pandemic may increase the risk of depression and anxiety in the general population. Individuals approaching or within older adulthood may be especially vulnerable to these psychosocial stressors and their impact on mental health outcomes. Consequently, there is an urgent need to identify protective factors for older adults. The purpose of the present study was to determine the relative contribution of coping flexibility (CF) and two distinct coping strategies, forward-focused and trauma-focused, on negative affect in persons 50 years of age and older during the COVID-19 pandemic. Method: Data were collected using an online survey, including questions about demographic information, coping, depression, and anxiety. Participants aged 50 and over were included in our analyses of depression (N = 800) and anxiety (N = 638). Results: Both higher CF and higher forward-focused coping predicted lower depression and lower anxiety. In contrast, higher trauma-focused coping predicted slightly higher depressive symptoms but was not a significant predictor of anxiety. Conclusion: Our findings suggest that higher forward-focused coping may serve as a protective factor in older adults during the pandemic and, therefore, may be an effective treatment target for mental health interventions.

Five-Year Change in Body Mass Index Predicts Conversion to Mild Cognitive Impairment or Dementia Only in APOE ɛ4 Allele Carriers

BACKGROUND

Body mass index (BMI) has been identified as an important modifiable lifestyle risk factor for dementia, but less is known about how BMI might interact with Apolipoprotein E ɛ4 (APOE ɛ4) carrier status to predict conversion to mild cognitive impairment (MCI) and dementia.

OBJECTIVE

The aim of this study was to investigate the interaction between APOE ɛ4 status and baseline (bBMI) and five-year BMI change (ΔBMI) on conversion to MCI or dementia in initially cognitively healthy older adults.

METHODS

The associations between bBMI, ΔBMI, APOE ɛ4 status, and conversion to MCI or dementia were investigated among 1,289 cognitively healthy elders from the National Alzheimer's Coordinating Center (NACC) database.

RESULTS

After five years, significantly more carriers (30.6%) converted to MCI or dementia than noncarriers (17.6%), p < 0.001, OR = 2.06. Neither bBMI (OR = 0.99, 95%CI = 0.96-1.02) nor the bBMI by APOE interaction (OR = 1.02, 95%CI = 0.96-1.08) predicted conversion. Although ΔBMI also did not significantly predict conversion (OR = 0.90, 95%CI = 0.78-1.04), the interaction between ΔBMI and carrier status was significant (OR = 0.72, 95%CI = 0.53-0.98). For carriers only, each one-unit decline in BMI over five years was associated with a 27%increase in the odds of conversion (OR = 0.73, 95%CI = 0.57-0.94).

CONCLUSION

A decline in BMI over five years, but not bBMI, was strongly associated with conversion to MCI or dementia only for APOE ɛ4 carriers. Interventions and behaviors aimed at maintaining body mass may be important for long term cognitive health in older adults at genetic risk for AD.

Brain Α-Tocopherol Concentration is Inversely Associated with Neurofibrillary Tangle Counts in Brain Regions Affected in Earlier Braak Stages: A Cross-Sectional Finding in the Oldest Old

Objectives

Higher vitamin E status has been associated with lower risk of Alzheimer's disease (AD). However, evidence of the association of vitamin E concentration in neural tissue with AD pathologies is limited.

Design

The cross-sectional relationship between the human brain concentrations of α- and γ-tocopherol and the severity of AD pathologies - neurofibrillary tangle (NFT) and neuritic plaque (NP) - was investigated.

Setting & Participants

Brains from 43 centenarians (≥ 98 years at death) enrolled in the Phase III of the Georgia Centenarian Study were collected at autopsy.

Measurements

Brain α- and γ-tocopherol concentrations (previously reported) were averaged from frontal, temporal, and occipital cortices. NP and NFT counts (previously reported) were assessed in frontal, temporal, parietal, entorhinal cortices, amygdala, hippocampus, and subiculum. NFT topological progression was assessed using Braak staging. Multiple linear regression was performed to assess the relationship between tocopherol concentrations and NP or NFT counts, with and without adjustment for covariates.

Results

Brain α-tocopherol concentrations were inversely associated with NFT but not NP counts in amygdala (β = -2.67, 95% CI [-4.57, -0.79]), entorhinal cortex (β = -2.01, 95% CI [-3.72, -0.30]), hippocampus (β = -2.23, 95% CI [-3.82, -0.64]), and subiculum (β = -2.52, 95% CI [-4.42, -0.62]) where NFT present earlier in its topological progression, but not in neocortices. Subjects with Braak III-IV had lower α-tocopherol (median = 69,622 pmol/g, IQR = 54,389-72,155 pmol/g) than those with Braak I-II (median = 72,108 pmol/g, IQR = 64,056-82,430 pmol/g), but the difference was of borderline significance (p = 0.063). γ-Tocopherol concentrations were not associated with either NFT or NP counts in any brain regions assessed.

Conclusions

Higher brain α-tocopherol level is specifically associated with lower NFT counts in brain structures affected in earlier Braak stages. Our findings emphasize the possible importance of α-tocopherol intervention timing in tauopathy progression and warrant future clinical trials.

Spouse-Appraised Memory Functioning Predicts Memory Decline Better Than Subjective Memory Complaints in Community Dwelling Older Adults at Genetic Risk for Alzheimer's Disease

Objective: Alzheimer's disease (AD) begins with subtle memory decline, years before dementia onset. The presence of subjective memory complaints (SMC) has been proposed as a marker of preclinical AD. However, recent evidence has demonstrated early and progressive loss of awareness of memory difficulties in non-demented older adults harboring AD pathology. We investigated the respective contributions of SMC and spouse-appraised memory functioning (SAM) to predict memory decline in a large cohort of community dwelling older adults. Methods: The Wisconsin Longitudinal Study collected cognitive data from a community-based cohort of 3,583 participants in both 2005 and 2011. The participant and the participant's spouse were each asked to rate the participant's memory functioning using a Likert scale. We predicted change in objective episodic memory with models including baseline SMC, baseline SAM, or both SMC and SAM. We also evaluated an awareness index (SMC minus SAM). We then tested the interaction between Apolipoprotein E (APOE ε4) carrier status and SMC/SAM to evaluate whether the effects were driven by individuals at-risk for AD pathology. Results: In separate models, SMC (-0.081 ± 0.036, p = 0.025) and SAM (-0.084 ± 0.278, p = 0.003) were both associated with memory decline over ~6 years. However, the AI was not significantly associated with memory decline (0.031 ± 0.024, p = 0.19). When both predictors were included in the same model, SAM (-0.074 ± 0.03, p = 0.0092) was associated with memory decline, while SMC was not significant (-0.061 ± 0.04, p = 0.99). The association between SAM and memory decline was stronger in the APOE ε4 carriers than in the non-carriers (APOE-by-SAM interaction: F = 6.07; p = 0.002), and follow up analyses revealed that SAM was particularly predictive of decline only for APOE ε4 carriers. The association between SMC and memory decline was independent of APOE ε4 carrier status (APOE-by-SMC interaction: F = 2.29; p = 0.13). Conclusions: Spouse-appraised memory functioning was more predictive of memory decline than SMC or an awareness index, particularly in APOE ε4 carriers, who are at increased risk for AD pathology.

The Mental Health Benefits of Physical Activity in Older Adults Survive the COVID-19 Pandemic

OBJECTIVE

To determine the relationship between the amount and intensity of physical activity performed by older adults in North America (United States and Canada) and their depression and anxiety symptoms while currently under social distancing guidelines (SDG) for the COVID-19 pandemic.

DESIGN

Descriptive cross-sectional study.

SETTING

Online survey conducted between April 9 and April 30, 2020, during the COVD-19 pandemic.

PARTICIPANTS

About 1,046 older adults over the age of 50 who live in North America.

MEASUREMENTS

Participants were asked about their basic demographic information, current health status, and the impact of the current SDG on their subjective state of mental health. Participants completed the Physical Activity Scale for the Elderly, to determine the amount and intensity of physical activity performed, as well as both the Geriatric Depression Scale and Geriatric Anxiety Scale, to ascertain the extent of their depression and anxiety-like symptoms.

RESULTS

Ninety-seven percent of participants indicated that they adhered to current SDG "Most of the time" or "Strictly." Participants who performed greater levels of physical activity experienced lower levels of depression-like symptoms when age, sex, and education were accounted for; however, no relationship between physical activity and anxiety-like symptoms was found. A hierarchical regression analysis that incorporated the intensity of physical activity performed (light, moderate, and vigorous) in the model indicated that greater light and strenuous activity, but not moderate, predicted lower depression-like symptoms.

CONCLUSIONS

These results suggest that performing even light physical activity during the COVID-19 pandemic may help alleviate some of the negative mental health impacts that older adults may be experiencing while isolated and adhering to SDG during the COVID-19 pandemic.

Defining a Centiloid scale threshold predicting long-term progression to dementia in patients attending the memory clinic: an [18F] flutemetamol amyloid PET study

PURPOSE

To evaluate cerebral amyloid-β(Aβ) pathology in older adults with cognitive complaints, visual assessment of PET images is approved as the routine method for image interpretation. In research studies however, Aβ-PET semi-quantitative measures are associated with greater risk of progression to dementia; but until recently, these measures lacked standardization. Therefore, the Centiloid scale, providing standardized Aβ-PET semi-quantitation, was recently validated. We aimed to determine the predictive values of visual assessments and Centiloids in non-demented patients, using long-term progression to dementia as our standard of truth.

METHODS

One hundred sixty non-demented participants (age, 54-86) were enrolled in a monocentric [¹⁸F] flutemetamol Aβ-PET study. Flutemetamol images were interpreted visually following the manufacturers recommendations. SUVr values were converted to the Centiloid scale using the GAAIN guidelines. Ninety-eight persons were followed until dementia diagnosis or were clinically stable for a median of 6 years (min = 4.0; max = 8.0). Twenty-five patients with short follow-up (median = 2.0 years; min = 0.8; max = 3.9) and 37 patients with no follow-up were excluded. We computed ROC curves predicting subsequent dementia using baseline PET data and calculated negative (NPV) and positive (PPV) predictive values.

RESULTS

In the 98 participants with long follow-up, Centiloid = 26 provided the highest overall predictive value = 87% (NPV = 85%, PPV = 88%). Visual assessment corresponded to Centiloid = 40, which predicted dementia with an overall predictive value = 86% (NPV = 81%, PPV = 92%). Inclusion of the 25 patients who only had a 2-year follow-up decreased the PPV = 67% (NPV = 88%), reflecting the many positive cases that did not progress to dementia after short follow-ups.

CONCLUSION

A Centiloid threshold = 26 optimally predicts progression to dementia 6 years after PET. Visual assessment provides similar predictive value, with higher specificity and lower sensitivity.

TRIAL REGISTRATION

Eudra-CT number: 2011-001756-12.

The fear of Alzheimer's disease: mediating effects of anxiety on subjective memory complaints

Objectives: To determine if the fear of developing Alzheimer's disease (FDAD) construct, in combination with similar psychoemotional factors, could help elucidate the nature of older adults' subjective memory complaints (SMCs) and subsequent objective memory performance.Methods: One hundred ninety-three healthy older adults (aged 65-93) were administered clinician and self-report measures of depression, worry, anxiety, illness attitudes, and memory, and each rated their concern with developing AD.Results: Self-reported FDAD was not associated with objective memory performance (p > .05). FDAD, trait anxiety, general anxiety, and general and illness-related worry were independently associated with subjective memory report (ps < .05). The relationship between FDAD and subjective memory report was mediated by measures of general trait and state anxiety, but not general worry or illness-specific worry.Conclusions: FDAD was not associated with objective memory functioning, suggesting AD concerns were not reflective of memory pathology. The mediating effect of anxiety on the relationship between FDAD and subjective memory report suggests that assessment of anxiety, beyond AD fear, may help identify older adults at risk for developing negative perceptions of memory and related distress.

Duration of Fame and Extent of Semantic Knowledge of Famous Names in Cognitively Intact Older Adults

Objective

The greater resilience of older memories relative to recent memories has primarily been demonstrated in clinical groups, but this phenomenon has been less extensively examined in cognitively intact older adults. Additionally, most studies of person-identity have only examined recognition or familiarity of a famous face or name, and there has been less systematic study of access to more specific person-identity semantic knowledge. The current study examined the effect of both memory age and extent of semantic knowledge on famous name recognition and retrieval of person-identity biographical information in healthy older adults.

Method

We examined recognition accuracy and response time of famous names at three time epochs (recent fame, transitory fame and enduring fame) in cognitively intact older adults. We also compared access to semantic knowledge that differed on the degree of specificity of biographical information: categorical, associative, and attribute knowledge.

Results

As predicted, participants recognized transitory famous names more quickly and accurately than recent famous names. Additionally, participants recognized enduring famous names more accurately than transitory famous names and recent names. We also found that categorical semantic knowledge was accessed more quickly and accurately than semantic knowledge for associative and attribute information.

Conclusions

These findings provide data on the cognitive structure and retrieval of person-identity knowledge and memory age in older cognitively intact individuals.

THE RELATIONSHIP BETWEEN COGNITION, FUNCTIONAL ABILITIES, AND THE LATENT DEMENTIA PHENOTYPE AMONG CENTENARIANS

Adequate assessment of cognitive abilities and functional capacity is essential for a diagnosis of dementia. However, cognition is only moderately related to functional status, and this relationship is poorly understood among centenarians, a group of older adults with high risk for dementia. A bifactor structural equation model can be used to delineate the variance attributed to dementia-specific related cognitive changes (i.e., the latent variable delta) and the variance due to general intelligence (i.e., g’). This study aimed to determine the validity of delta as a marker of cognitive decline among centenarians. It was hypothesized that delta was correlated with cognitive status, functional abilities and, dementia severity. Overall, 244 community dwelling centenarians (Mage = 100.58, 84.8% female) were recruited through the Georgia Centenarian Study, a population-based study of octogenarians and centenarians from northern Georgia. Older adults were administered measures of cognition and a self-report measure of functional abilities. Latent variable scores (i.e., g’ and delta) were modeled and correlated with standard global cognitive screening measures (i.e., MMSE) and measures of dementia severity. Results indicate that delta was significantly correlated with functional ability and cognitive abilities. Consistent with our hypotheses, delta was also significantly related to dementia severity. Overall, estimates of the latent dementia phenotype, delta, were significantly related to cognitive and functional abilities among centenarians, providing validation of delta as a useful index of dementia severity.

Convergent Synthesis of the NS5B Inhibitor GSK8175 Enabled by Transition Metal Catalysis

A convergent eight-stage synthesis of the boron-containing NS5B inhibitor GSK8175 is described. The previous route involves 13 steps in a completely linear sequence, with an overall 10% yield. Key issues include a multiday S_NAr arylation of a secondary sulfonamide using HMPA as solvent, multiple functional group interconversions after all of the carbon atoms are installed (including a Sandmeyer halogenation), use of carcinogenic chloromethyl methyl ether to install a protecting group late in the synthesis, and an unreliable Pd-catalyzed Miyaura borylation as the penultimate step. We have devised an orthogonal approach using a Chan-Lam coupling between a halogenated aryl pinacol boronate ester and an aryl methanesulfonamide. This reaction is performed using a cationic Cu(I) precatalyst, which can be easily generated in situ using KPF₆ as a halide abstractor. High-throughput screening revealed a new Pd catalyst system to effect the penultimate borylation chemistry using simple monodentate phosphine ligands, with PCyPh₂ identified as optimal. Reaction progress analysis of this borylation indicated likely mass-transfer rate limitations under standard conditions using KOAc as the base. We have devised a K₂CO₃/pivalic acid system as an alternative, which dramatically outperforms the standard conditions. This new synthesis proceeds in eight stages with a 20% overall yield.

Differential 5-year brain atrophy rates in cognitively declining and stable APOE-ε4 elders

OBJECTIVE

The apolipoprotein E (APOE) ε4 allele is the most important genetic risk factor for late-onset Alzheimer's disease. Many ε4 carriers, however, never develop Alzheimer's disease. The purpose of this study is to characterize the variability in phenotypic expression of the ε4 allele, as measured by the longitudinal trajectory of cognitive test scores and MRI brain volumes, in cognitively intact elders.

METHOD

Healthy older adults, ages 65-85, participated in a 5-year longitudinal study that included structural MRI and cognitive testing administered at baseline and at 1.5 and 5 years postenrollment. Participants included 22 ε4 noncarriers, 15 ε4 carriers who experienced a decline in cognition over the 5-year interval, and 11 ε4 carriers who remained cognitively stable.

RESULTS

No baseline cognitive or volumetric group differences were observed. Compared to noncarriers, declining ε4 carriers had significantly greater rates of atrophy in left (p = .001, Cohen's d = .691) and right (p = .003, d = .622) cortical gray matter, left (p = .003, d = .625) and right (p = .020, d = .492) hippocampi, and greater expansion of the right inferior lateral ventricle (p < .001, d = .751) over 5 years.

CONCLUSIONS

This study illustrates the variability in phenotypic expression of the ε4 allele related to neurodegeneration. Specifically, only those individuals who exhibited longitudinal declines in cognitive function experienced concomitant changes in brain volume. Future research is needed to better understand the biological and lifestyle factors that may influence the expression of the ε4 allele. (PsycINFO Database Record

Synthesis and antiproliferative activity of derivatives of the phyllanthusmin class of arylnaphthalene lignan lactones

A series of arylnaphthalene lignan lactones based on the structure of the phyllanthusmins, a class of potent natural products possessing diphyllin as the aglycone, has been synthesized and screened for activity against multiple cancer cell lines. SAR exploration was performed on both the carbohydrate and lactone moieties of this structural class. These studies have revealed the importance of functionalization of the carbohydrate hydroxy groups with both acetylated and methylated analogues showing increased potency relative to those with unsubstituted sugar moieties. In addition, the requirement for the presence and position of the C-ring lactone has been demonstrated through reduction and selective re-oxidation of the lactone ring. The most potent compound in this study displayed an IC₅₀ value of 18 nM in an HT-29 assay with several others ranging from 50 to 200 nM. In an effort to elucidate their potential mechanism(s) of action, the DNA topoisomerase IIa inhibitory activity of the most potent compounds was examined based on previous reports of structurally similar compounds, but does not appear to contribute significantly to their antiproliferative effects.

Guillain-BarrÉ syndrome subtype diagnosis: A prospective multicentric European study

INTRODUCTION

There is uncertainty as to whether the Guillain-Barré syndrome (GBS) subtypes, acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy (AMAN), can be diagnosed electrophysiologically.

METHODS

We prospectively included 58 GBS patients. Electrodiagnostic testing (EDX) was performed at means of 5 and 33 days after disease onset. Two traditional and one recent criteria sets were used to classify studies as demyelinating or axonal. Results were correlated with anti-ganglioside antibodies and reversible conduction failure (RCF).

RESULTS

No classification shifts were observed, but more patients were classified as axonal with recent criteria. RCF and anti-ganglioside antibodies were present in both subtypes, more frequently in the axonal subtype.

DISCUSSION

Serial EDX has no effect on GBS subtype proportions. The absence of exclusive correlation with RCF and anti-ganglioside antibodies may challenge the concept of demyelinating and axonal GBS subtypes based upon electrophysiological criteria. Frequent RCF indicates that nodal/paranodal alterations may represent the main pathophysiology. Muscle Nerve, 2018.

Motor timing intraindividual variability in amnestic mild cognitive impairment and cognitively intact elders at genetic risk for Alzheimer's disease

INTRODUCTION

Intraindividual variability (IIV) in motor performance has been shown to predict future cognitive decline. The apolipoprotein E-epsilon 4 (APOE-ε4) allele is also a well-established risk factor for memory decline. Here, we present novel findings examining the influence of the APOE-ε4 allele on the performance of asymptomatic healthy elders in comparison to individuals with amnestic MCI (aMCI) on a fine motor synchronization, paced finger-tapping task (PFTT).

METHOD

Two Alzheimer's disease (AD) risk groups, individuals with aMCI (n = 24) and cognitively intact APOE-ε4 carriers (n = 41), and a control group consisting of cognitively intact APOE-ε4 noncarriers (n = 65) completed the Rey Auditory Verbal Learning Test and the PFTT, which requires index finger tapping in synchrony with a visual stimulus (interstimulus interval = 333 ms).

RESULTS

Motor timing IIV, as reflected by the standard deviation of the intertap interval (ITI), was greater in the aMCI group than in the two groups of cognitively intact elders; in contrast, all three groups had statistically equivalent mean ITI. No significant IIV differences were observed between the asymptomatic APOE-ε4 carriers and noncarriers. Poorer episodic memory performance was associated with greater IIV, particularly in the aMCI group.

CONCLUSIONS

Results suggest that increased IIV on a fine motor synchronization task is apparent in aMCI. This IIV measure was not sensitive in discriminating older asymptomatic individuals at genetic risk for AD from those without such a genetic risk. In contrast, episodic memory performance, a well-established predictor of cognitive decline in preclinical AD, was able to distinguish between the two cognitively intact groups based on genetic risk.

A quarter century of advances in the statistical analysis of longitudinal neuropsychological data

OBJECTIVE

Over the last 25 years, there has been an unprecedented increase in federal funding for large-scale longitudinal studies, many of which collect neuropsychological or neuroimaging outcome measures. These studies have collected data from thousands of study participants across multiple waves of data collection over many years. With the increased availability of longitudinal data, data sharing policies have become more liberal, thereby offering significant opportunities for interested researchers to carry out their own longitudinal research with these data. At the same time, these opportunities have stimulated new conceptualizations of longitudinal change and have led to the development of novel approaches toward analysis of longitudinal data. My aim is to review these new conceptualizations and novel data analytic approaches.

METHOD

In this article, I describe the state of the field a quarter century ago with respect to available longitudinal studies, and I trace the growth of federally funded longitudinal studies over the last 25 years by describing 18 of these projects, many of which are still collecting data. In the second part of this article, I describe changes in the methods used to analyze longitudinal data, transitioning from the paired t test and repeated measures ANOVA to latent change scores, linear mixed effects modeling, and latent growth curve models. Changes in the approach to management of missing data are also discussed.

CONCLUSIONS

Future studies should abandon traditional longitudinal analytic methods in favor of contemporary approaches given their increased power, greater accuracy, and widespread availability. (PsycINFO Database Record

Five-Year Longitudinal Brain Volume Change in Healthy Elders at Genetic Risk for Alzheimer's Disease

Neuropathological changes associated with Alzheimer's disease (AD) precede symptom onset by more than a decade. Possession of an apolipoprotein E (APOE) ɛ4 allele is the strongest genetic risk factor for late onset AD. Cross-sectional studies of cognitively intact elders have noted smaller hippocampal/medial temporal volumes in ɛ4 carriers (ɛ4+) compared to ɛ4 non-carriers (ɛ4-). Few studies, however, have examined long-term, longitudinal, anatomical brain changes comparing healthy ɛ4+ and ɛ4- individuals. The current five-year study examined global and regional volumes of cortical and subcortical grey and white matter and ventricular size in 42 ɛ4+ and 30 ɛ4- individuals. Cognitively intact participants, ages 65-85 at study entry, underwent repeat anatomical MRI scans on three occasions: baseline, 1.5, and 4.75 years. Results indicated no between-group volumetric differences at baseline. Over the follow-up interval, the ɛ4+ group experienced a greater rate of volume loss in total grey matter, bilateral hippocampi, right hippocampal subfields, bilateral lingual gyri, bilateral parahippocampal gyri, and right lateral orbitofrontal cortex compared to the ɛ4- group. Greater loss in grey matter volumes in ɛ4+ participants were accompanied by greater increases in lateral, third, and fourth ventricular volumes. Rate of change in white matter volumes did not differentiate the groups. The current results indicate that longitudinal measurements of brain atrophy can serve as a sensitive biomarker for identifying neuropathological changes in persons at genetic risk for AD and potentially, for assessing the efficacy of treatments designed to slow or prevent disease progression during the preclinical stage of AD.

Diffusion Tensor Imaging Predictors of Episodic Memory Decline in Healthy Elders at Genetic Risk for Alzheimer's Disease

OBJECTIVES

White matter (WM) integrity within the mesial temporal lobe (MTL) is important for episodic memory (EM) functioning. The current study investigated the ability of diffusion tensor imaging (DTI) in MTL WM tracts to predict 3-year changes in EM performance in healthy elders at disproportionately higher genetic risk for Alzheimer's disease (AD).

METHODS

Fifty-one cognitively intact elders (52% with family history (FH) of dementia and 33% possessing an Apolipoprotein E ε4 allelle) were administered the Rey Auditory Verbal Learning Test (RAVLT) at study entry and at 3-year follow-up. DTI scanning, conducted at study entry, examined fractional anisotropy and mean, radial and axial diffusion within three MTL WM tracts: uncinate fasciculus (UNC), cingulate-hippocampal (CHG), and fornix-stria terminalis (FxS). Correlations were performed between residualized change scores computed from RAVLT trials 1-5, immediate recall, and delayed recall scores and baseline DTI measures; MTL gray matter (GM) and WM volumes; demographics; and AD genetic and metabolic risk factors.

RESULTS

Higher MTL mean and axial diffusivity at baseline significantly predicted 3-year changes in EM, whereas baseline MTL GM and WM volumes, FH, and metabolic risk factors did not. Both ε4 status and DTI correlated with change in immediate recall.

CONCLUSIONS

Longitudinal EM changes in cognitively intact, healthy elders can be predicted by disruption of the MTL WM microstructure. These results are derived from a sample with a disproportionately higher genetic risk for AD, suggesting that the observed WM disruption in MTL pathways may be related to early neuropathological changes associated with the preclinical stage of AD. (JINS, 2016, 22, 1005-1015).

Does cognitive self-consciousness link older adults' cognitive functioning to obsessive-compulsive symptoms?

To elucidate how obsessional symptoms might develop or intensify in late-life, we tested a risk model. We posited that cognitive self-consciousness (CSC), a tendency to be aware of and monitor thinking, would increase reactivity to aging-related cognitive changes and mediate the relationship between cognitive functioning and obsessive-compulsive disorder (OCD) symptoms. Older adults (Mage = 76.7 years) completed the Dementia Rating Scale-2 (DRS-2), a CSC measure, and an OCD symptom measure up to four times over 18 months. A model that included DRS-2 age and education adjusted total score as the indicator of cognitive functioning fit the data well, and CSC score change mediated the relationship between initial cognitive functioning and changes in OCD symptoms. In tests of a model that included DRS-2 Initiation/Perseveration (I/P) and Conceptualization subscale scores, the model again fit the data well. Conceptualization scores, but not I/P scores, were related to later OCD symptoms, and change in CSC scores again mediated the relationship. Lower scores on initial cognitive functioning measures predicted increases in CSC scores over time, which in turn predicted increases in OCD symptoms over the 18 months of the study. Implications for understanding late-life obsessional problems are discussed.

Brain pathologies in extreme old age

With an emphasis on evolving concepts in the field, we evaluated neuropathologic data from very old research volunteers whose brain autopsies were performed at the University of Kentucky Alzheimer's Disease Center, incorporating data from the Georgia Centenarian Study (n = 49 cases included), Nun Study (n = 17), and University of Kentucky Alzheimer's Disease Center (n = 11) cohorts. Average age of death was 102.0 (range: 98-107) years overall. Alzheimer's disease pathology was not universal (62% with "moderate" or "frequent" neuritic amyloid plaque densities), whereas frontotemporal lobar degeneration was absent. By contrast, some hippocampal neurofibrillary tangles (including primary age-related tauopathy) were observed in every case. Lewy body pathology was seen in 16.9% of subjects and hippocampal sclerosis of aging in 20.8%. We describe anatomic distributions of pigment-laden macrophages, expanded Virchow-Robin spaces, and arteriolosclerosis among Georgia Centenarians. Moderate or severe arteriolosclerosis pathology, throughout the brain, was associated with both hippocampal sclerosis of aging pathology and an ABCC9 gene variant. These results provide fresh insights into the complex cerebral multimorbidity, and a novel genetic risk factor, at the far end of the human aging spectrum.

Trichormamides C and D, antiproliferative cyclic lipopeptides from the cultured freshwater cyanobacterium cf. Oscillatoria sp. UIC 10045

Extract from the cultured freshwater cf. Oscillatoria sp. UIC 10045 showed antiproliferative activity against HT-29 cell line. Bioassay-guided fractionation led to the isolation of two new cyclic lipopeptides, named trichormamides C (1) and D (2). The planar structures were determined by combined analyses of HRESIMS, Q-TOF ESIMS/MS, and 1D and 2D NMR spectra. The absolute configurations of the amino acid residues were assigned by advanced Marfey's analysis after partial and complete acid hydrolysis. Trichormamides C (1) is a cyclic undecapeptide and D (2) is a cyclic dodecapeptide, both containing a lipophilic β-aminodecanoic acid residue. Trichormamide C (1) displayed antiproliferative activities against HT-29 and MDA-MB-435 cancer cell lines with IC50 values of 1.7 and 1.0μM, respectively, as well as anti-Mycobacterium tuberculosis activity with MIC value of 23.8μg/mL (17.3μM). Trichormamide D (2) was found to be less potent against both HT-29 and MDA-MB-435 cancer cell lines with IC50 values of 11.5 and 11.7μM, respectively.

Resting State Functional Connectivity in Mild Traumatic Brain Injury at the Acute Stage: Independent Component and Seed-Based Analyses

Mild traumatic brain injury (mTBI) accounts for more than 1 million emergency visits each year. Most of the injured stay in the emergency department for a few hours and are discharged home without a specific follow-up plan because of their negative clinical structural imaging. Advanced magnetic resonance imaging (MRI), particularly functional MRI (fMRI), has been reported as being sensitive to functional disturbances after brain injury. In this study, a cohort of 12 patients with mTBI were prospectively recruited from the emergency department of our local Level-1 trauma center for an advanced MRI scan at the acute stage. Sixteen age- and sex-matched controls were also recruited for comparison. Both group-based and individual-based independent component analysis of resting-state fMRI (rsfMRI) demonstrated reduced functional connectivity in both posterior cingulate cortex (PCC) and precuneus regions in comparison with controls, which is part of the default mode network (DMN). Further seed-based analysis confirmed reduced functional connectivity in these two regions and also demonstrated increased connectivity between these regions and other regions of the brain in mTBI. Seed-based analysis using the thalamus, hippocampus, and amygdala regions further demonstrated increased functional connectivity between these regions and other regions of the brain, particularly in the frontal lobe, in mTBI. Our data demonstrate alterations of multiple brain networks at the resting state, particularly increased functional connectivity in the frontal lobe, in response to brain concussion at the acute stage. Resting-state functional connectivity of the DMN could serve as a potential biomarker for improved detection of mTBI in the acute setting.

Genetic risk for Alzheimer's disease alters the five-year trajectory of semantic memory activation in cognitively intact elders

Healthy aging is associated with cognitive declines typically accompanied by increased task-related brain activity in comparison to younger counterparts. The Scaffolding Theory of Aging and Cognition (STAC) (Park and Reuter-Lorenz, 2009; Reuter-Lorenz and Park, 2014) posits that compensatory brain processes are responsible for maintaining normal cognitive performance in older adults, despite accumulation of aging-related neural damage. Cross-sectional studies indicate that cognitively intact elders at genetic risk for Alzheimer's disease (AD) demonstrate patterns of increased brain activity compared to low risk elders, suggesting that compensation represents an early response to AD-associated pathology. Whether this compensatory response persists or declines with the onset of cognitive impairment can only be addressed using a longitudinal design. The current prospective, 5-year longitudinal study examined brain activation in APOE ε4 carriers (N=24) and non-carriers (N=21). All participants, ages 65-85 and cognitively intact at study entry, underwent task-activated fMRI, structural MRI, and neuropsychological assessments at baseline, 18, and 57 months. fMRI activation was measured in response to a semantic memory task requiring participants to discriminate famous from non-famous names. Results indicated that the trajectory of change in brain activation while performing this semantic memory task differed between APOE ε4 carriers and non-carriers. The APOE ε4 group exhibited greater activation than the Low Risk group at baseline, but they subsequently showed a progressive decline in activation during the follow-up periods with corresponding emergence of episodic memory loss and hippocampal atrophy. In contrast, the non-carriers demonstrated a gradual increase in activation over the 5-year period. Our results are consistent with the STAC model by demonstrating that compensation varies with the severity of underlying neural damage and can be exhausted with the onset of cognitive symptoms and increased structural brain pathology. Our fMRI results could not be attributed to changes in task performance, group differences in cerebral perfusion, or regional cortical atrophy.

Octogenarian and centenarian performance on the Fuld Object Memory Evaluation

The Fuld Object Memory Evaluation (FOME) has considerable utility for cognitive assessment in older adults, but there are few normative data, particularly for the oldest old. In this study, 80 octogenarians and 244 centenarians from the Georgia Centenarian Study completed the FOME. Total and trial-to-trial performance on the storage, retrieval, repeated retrieval, and ineffective reminder indices were assessed. Additional data stratified by age group, education, and cognitive impairment are provided in the Supplemental data. Octogenarians performed significantly better than centenarians on all FOME measures. Neither age group benefitted from additional learning trials beyond Trial 3 for storage and Trial 2 for retention and retrieval. Ineffective reminders showed no change across learning trials for octogenarians, while centenarians improved only between Trials 1 and 2. This minimal improvement past Trial 2 indicates that older adults might benefit from a truncated version of the test that does not include trials three through five, with the added benefit of reducing testing burden in this population.

Trichormamides A and B with Antiproliferative Activity from the Cultured Freshwater Cyanobacterium Trichormus sp. UIC 10339

Two new cyclic lipopeptides, trichormamides A (1) and B (2), were isolated from the cultured freshwater cyanobacterium Trichormus sp. UIC 10339. The strain was obtained from a sample collected in Raven Lake in Northern Wisconsin. The planar structures of trichormamides A (1) and B (2) were determined using a combination of spectroscopic analyses including HRESIMS and 1D and 2D NMR experiments. The absolute configurations of the amino acid residues were assigned by the advanced Marfey's method after acid hydrolysis. Trichormamide A (1) is a cyclic undecapeptide containing two D-amino acid residues (D-Tyr and D-Leu) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) is a cyclic dodecapeptide characterized by the presence of four nonstandard α-amino acid residues (homoserine, N-methylisoleucine, and two 3-hydroxyleucines) and one β-amino acid residue (β-aminodecanoic acid). Trichormamide B (2) was cytotoxic against MDA-MB-435 and HT-29 cancer cell lines with IC50 values of 0.8 and 1.5 μM, respectively.

Rocaglamide, silvestrol and structurally related bioactive compounds from Aglaia species

Covering: 2006 to 2013. Investigations on the chemistry and biology of rocaglamide, silvestrol and structurally related bioactive compounds from Aglaia species during the period 2006-2013 are reviewed. Included are new phytochemical studies of naturally occurring rocaglamide derivatives, an update on synthetic methods for cyclopenta[b]benzofurans, and a description of the recent biological evaluation and mechanism-of-action studies on compounds of this type.

Physical activity reduces hippocampal atrophy in elders at genetic risk for Alzheimer's disease

We examined the impact of physical activity (PA) on longitudinal change in hippocampal volume in cognitively intact older adults at varying genetic risk for the sporadic form of Alzheimer's disease (AD). Hippocampal volume was measured from structural magnetic resonance imaging (MRI) scans administered at baseline and at an 18-month follow-up in 97 healthy, cognitively intact older adults. Participants were classified as High or Low PA based on a self-report questionnaire of frequency and intensity of exercise. Risk status was defined by the presence or absence of the apolipoprotein E-epsilon 4 (APOE-ε4) allele. Four subgroups were studied: Low Risk/High PA (n = 24), Low Risk/Low PA (n = 34), High Risk/High PA (n = 22), and High Risk/Low PA (n = 17). Over the 18 month follow-up interval, hippocampal volume decreased by 3% in the High Risk/Low PA group, but remained stable in the three remaining groups. No main effects or interactions between genetic risk and PA were observed in control brain regions, including the caudate, amygdala, thalamus, pre-central gyrus, caudal middle frontal gyrus, cortical white matter (WM), and total gray matter (GM). These findings suggest that PA may help to preserve hippocampal volume in individuals at increased genetic risk for AD. The protective effects of PA on hippocampal atrophy were not observed in individuals at low risk for AD. These data suggest that individuals at genetic risk for AD should be targeted for increased levels of PA as a means of reducing atrophy in a brain region critical for the formation of episodic memories.

Assessing Older Adults' Obsessive-Compulsive Disorder Symptoms: Psychometric Characteristics of the Obsessive Compulsive Inventory-Revised

The lack of Obsessive-Compulsive disorder (OCD) symptom measures validated for use with older adults has hindered research and treatment development for the age group. We evaluated the Obsessive-Compulsive Inventory-Revised (OCI-R; Foa et al., 2002) with participants aged 65 and older (N = 180) to determine if the measure was an effective tool for evaluating obsessional symptoms. Participants completed the OCI-R and a comprehensive assessment battery up to four times over approximately 18 months. Results supported the well-replicated latent structure of the OCI-R (i.e., Washing, Checking, Ordering, Obsessing, Hoarding, and Neutralizing.). OCI-R total score was robustly associated with OCD symptoms assessed 18 months later by clinical interview, while scores on self-report measures of worry, general anxiety, and depression were not. Results indicate the OCI-R is an effective OCD symptom measure for older adults, although replication with additional older adult samples is needed.

Performance variability during a multitrial list-learning task as a predictor of future cognitive decline in healthy elders

INTRODUCTION

In clinical settings, neuropsychological test performance is traditionally evaluated with total summary scores (TSS). However, recent studies demonstrated that indices of intraindividual variability (IIV) yielded unique information complementing TSS. This 18-month longitudinal study sought to determine whether IIV indices derived from a multitrial list-learning test (the Rey Auditory Verbal Learning Test) provided incremental utility in predicting cognitive decline in older adults compared to TSS.

METHOD

Ninety-nine cognitively intact older adults (aged 65 to 89 years) underwent neuropsychological testing (including the Rey Auditory Verbal Learning Test) at baseline and 18-month follow-up. Participants were classified as cognitively stable (n = 65) or declining (n = 34) based on changes in their neuropsychological test performance. Logistic regression modeling tested the ability of baseline TSS indices (sum of Trials 1-5, immediate recall, and delayed recall) and IIV indices (lost access and gained access) to discriminate between stable and declining individuals.

RESULTS

Higher values of both lost access and gained access at baseline were associated with an increased risk for decline at 18-month follow-up. Further, the IIV indices provided predictive utility above and beyond the TSS indices.

CONCLUSION

These results highlight the value of analyzing IIV in addition to TSS during neuropsychological evaluation in older adults. High levels of IIV may reflect impairment in anterograde memory systems and/or executive dysfunction that may serve as a prognostic indicator of cognitive decline.

Recognition of famous names predicts cognitive decline in healthy elders

OBJECTIVE

The ability to recognize familiar people is impaired in both Mild Cognitive Impairment (MCI) and Alzheimer's Dementia (AD). In addition, both groups often demonstrate a time-limited temporal gradient (TG) in which well known people from decades earlier are better recalled than those learned recently. In this study, we examined the TG in cognitively intact elders for remote famous names (1950-1965) compared to more recent famous names (1995-2005). We hypothesized that the TG pattern on a famous name recognition task (FNRT) would predict future cognitive decline, and also show a significant correlation with hippocampal volume.

METHOD

Seventy-eight healthy elders (ages 65-90) with age-appropriate cognitive functioning at baseline were administered a FNRT. Follow-up testing 18 months later produced two groups: Declining (≥ 1 SD reduction on at least one of three measures) and Stable (< 1 SD).

RESULTS

The Declining group (N = 27) recognized fewer recent famous names than the Stable group (N = 51), although recognition for remote names was comparable. Baseline MRI volumes for both the left and right hippocampi were significantly smaller in the Declining group than the Stable group. Smaller baseline hippocampal volume was also significantly correlated with poorer performance for recent, but not remote famous names. Logistic regression analyses indicated that baseline TG performance was a significant predictor of group status (Declining vs. Stable) independent of chronological age and APOE ε4 inheritance.

CONCLUSIONS

The TG for famous name recognition may serve as an early preclinical cognitive marker of cognitive decline in healthy older individuals.

Administration and environment considerations in computer-based sports-concussion assessment

Computer-based testing has become a vital tool for the assessment of sport-related concussion (SRC). An increasing number of papers have been published on this topic, focusing on subjects such as the purpose and validity of baseline testing, the performance of special populations on computer-based tests, the psychometric properties of different computerized neurocognitive tools, and considerations for valid and reliable administration of these tools. The current paper describes several considerations regarding computerized test design, input and output devices, and testing environment that should be described explicitly when administering computer-based cognitive testing, regardless of whether the assessment is used for clinical or research purposes. The paper also reviews the conclusions of recent literature (2007-2013) using computer-based testing for the assessment of SRC, with special attention to the methods used in these studies. We also present an appendix checklist for clinicians and researchers that may be helpful in ensuring proper attention to factors that could influence the reliability and validity of computer-based cognitive testing. We believe that explicit attention to these technological factors may lead to the development of standards for the development and implementation of computer-based tests. Such standards have the potential to enhance the accuracy and utility of computer-based tests in SRC.