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INTRODUCTION: Poorer baseline functioning is associated with long-term cognitive decline among Hispanic older adults, but little is known about associations of these factors with Alzheimer's disease (AD) neuroimaging biomarkers. METHODS: A total of 461 Hispanic and White non-Hispanic (NHW) older adults who are cognitively normal (n = 76), had impaired cognition without mild cognitive impairment (MCI) (n = 41), or carried a diagnosis of MCI (n = 253) or dementia (n = 91) completed neuropsychological and functional assessment, genetic testing, and brain magnetic resonance imaging (MRI). Structural equation modeling (SEM) was used to examine predictive associations between functional and cognitive measures of AD neuroimaging biomarkers. RESULTS: MRI volumes significantly predicted functional limitations in both groups. Sex and amyloid load significantly predicted functional limitations among the Hispanic group only. Years of education and MRI regional volume were the strongest predictors of cognition among both groups. DISCUSSION: Results indicate that functional performance is associated with early AD biomarkers among Hispanic older adults. Clinical implications are discussed. Highlights: The current study addresses health disparities in Alzheimer's disease (AD) and related dementia assessment among Hispanics by identifying measures sensitive to early AD biomarkers.Associations of functional measures with AD genetic and neuroimaging biomarkers revealed that similarities in these associations exist between Hispanic and White non-Hispanic individuals, but biological sex and amyloid load significantly predicted functional limitations among the Hispanic group only.These results have clinical implications for physicians who treat Hispanic AD patients and indicate that when compared to traditional diagnostic assessments, functional assessments may better aid in AD diagnostic precision among Hispanics.

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OBJECTIVE: To explore the relationship between age, education, sex, and ApoE4 (+) status to brain volume among a cohort with amnestic mild cognitive impairment (aMCI). METHOD: One hundred and twenty-three participants were stratified into Hispanic (n = 75) and White non-Hispanic (WNH, N = 48). Multiple linear regression analyses were conducted with age, education, sex, and ApoE4 status as predictor variables and left and right combined MRI volumes of the hippocampus, parahippocampus, and entorhinal cortex as dependent variables. Variations in head sizes were corrected by normalization with a total intracranial volume measurement. RESULTS: Bonferroni-corrected results indicated that when controlling for ApoE4 status, education, and age, sex was a significant predictor of hippocampal volume among the Hispanic group (ß = .000464, R2 = .196, p < .01) and the WNH group (ß = .000455, R2 = .195, p < .05). Education (ß = .000028, R2 = .168, p < .01) and sex (ß = .000261, R2 = .168, p < .01) were significant predictors of parahippocampal volume among the Hispanic MCI group when controlling for the effects of ApoE4 status and age. One-way ANCOVAs comparing hippocampal and parahippocampal volume between males and females within groups revealed that females had significantly larger hippocampal volumes (p < .05). Hispanic females had significantly larger hippocampal (p < .001) and parahippocampal (p < .05) volume compared to males. No sex differences in parahippocampal volume were noted among WNHs. CONCLUSIONS: Biological sex, rather than ApoE4 status, was a greater predictor of hippocampal volume among Hispanic and WNH females. These findings add to the mixed literature on sex differences in dementia research and highlight continued emphasis on ethnic populations to elucidate on neurodegenerative disparities.

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The effect of acculturation on cognition was examined among 142 older Hispanics: cognitively normal [CN; n = 70], Mild Cognitive Impairment, amnestic [aMCI; n = 27], and Dementia [D; n = 45]. Acculturation levels (high vs. low) were determined using the Short Acculturation Scale for Hispanics (SASH). ANCOVAs used a wide variety of neuropsychological tests as independent variables controlling for age and education. Among CN subjects, the highly acculturated group performed better on Logical Memory delayed recall (LM-II) [F(1, 56) = 9.26, p < .001, ηp2 = 0.14], Digit Span Forward [F(1, 56) = 4.37, p < .05, ηp2 = 0.07], Trail Making Test A [F(1, 56) = 7.74, p < .05, ηp2 = 0.12], and Trail Making Test B [F(1, 56) = 4.66, p = .03, ηp2 = 0.08], indicating that high acculturation was associated with a better performance on tests of episodic memory, auditory attention, working memory, cognitive flexibility, and processing speed among CN Hispanics. ANCOVA analyses were not significant among the other groups. In the absence of acculturation scales in clinical practice, caution should be exerted when interpreting neurocognitive results.

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OBJECTIVES: There are few standardized, Spanish-language diagnostic tools to help identify Hispanic persons at early stages of Alzheimer's disease (AD). This study evaluated the accuracy of the Spanish version of the Repeatable Battery for the Assessment of Neuropsychological Status-Update (RBANS) in predicting AD in older Hispanic adults in the United States reporting memory problems. METHODS: We analyzed data from age, sex, and education level propensity score-matched Hispanic memory clinic patients with (n = 38) and without (n = 38) a clinical diagnosis of AD. Estimates of diagnostic accuracy included sensitivity, specificity, predictive value, and receiver operating characteristic analysis. RESULTS: After controlling for sex and matched pairs, the Total Scale score [area under curve (AUC) = 0.7417] and the Immediate (AUC = 0.7258) and Delayed (AUC = 0.7735) Memory index scores provided better estimates of diagnostic accuracy than Language, Attention, and Visuospatial/Constructional index scores. A minus 2-standard deviation (SD) cut point enhanced the predictive probability of the Delayed Memory index score. A cut point of -1.5 SD optimized the predictive probability of the Total Scale score. CONCLUSIONS: These results suggest that optimal cutoff values for the RBANS Delayed Memory index and Total Scale scores that may help identify Hispanic patients with AD as part of a comprehensive diagnostic AD assessment.

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OBJECTIVES: This study examined the association of cultural factors and literacy to neuropsychological performance and measures of regional brain atrophy among Hispanic elders diagnosed with amnestic Mild Cognitive Impairment (aMCI). METHOD: Acculturation and literacy levels were measured among 45 subjects tested in Spanish; their primary language. Scores for measures of memory, executive functioning, and verbal fluency, as well as volumetric analysis of MRI scans of left hemisphere structures commonly affected by Alzheimer's disease (AD) were examined. Linear regression models were employed to examine the association of acculturation and literacy to neuropsychological performance and MRI measures. RESULTS: After controlling for age, higher literacy levels were associated with better performance on phonemic verbal fluency (r = 0.300, p < .05), while higher levels of acculturation to the U.S. was associated with poorer performance on category verbal fluency (r = 0.300, p < .05). There was a significant inverse relationship after controlling for age between literacy and the left entorhinal cortex (r = -0.455, p < .05), left precuneus (r = -0.457, p < .05), and left posterior cingulate (r = -0.415, p < .05). CONCLUSIONS: Results of the current pilot study indicate that high acculturation to the U.S. among aMCI immigrants from Latin-American countries may hinder performance on verbal learning measures when they are administered in one's primary language. Moreover, in this cohort, a higher literacy level, which is indicative of greater cognitive reserve, was associated with better performance in language measures, but with greater atrophy in brain regions susceptible to neurodegenerative disease. These preliminary findings should be further examined among larger cohorts and using more diverse measures, which capture other cultural constructs.

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BACKGROUND: Fibropapillomatosis (FP) is a neoplastic disease characterized by cutaneous tumours that has been documented to infect all sea turtle species. Chelonid fibropapilloma-associated herpesvirus (CFPHV) is believed to be the aetiological agent of FP, based principally on consistent PCR-based detection of herpesvirus DNA sequences from FP tumours. We used a recently described PCR-based assay that targets 3 conserved CFPHV genes, to survey 208 green turtles (Chelonia mydas). This included both FP tumour exhibiting and clinically healthy individuals. An additional 129 globally distributed clinically healthy individual sea turtles; representing four other species were also screened. RESULTS: CFPHV DNA sequences were obtained from 37/37 (100%) FP exhibiting green turtles, and 45/300 (15%) clinically healthy animals spanning all five species. Although the frequency of infected individuals per turtle population varied considerably, most global populations contained at least one CFPHV positive individual, with the exception of various turtle species from the Arabian Gulf, Northern Indian Ocean and Puerto Rico. Haplotype analysis of the different gene markers clustered the CFPHV DNA sequences for two of the markers (UL18 and UL22) in turtles from Turks and Caicos separate to all others, regardless of host species or geographic origin. CONCLUSION: Presence of CFPHV DNA within globally distributed samples for all five species of sea turtle was confirmed. While 100% of the FP exhibiting green turtles yielded CFPHV sequences, surprisingly, so did 15% of the clinically healthy turtles. We hypothesize that turtle populations with zero (0%) CFPHV frequency may be attributed to possible environmental differences, diet and/or genetic resistance in these individuals. Our results provide first data on the prevalence of CFPHV among seemingly healthy turtles; a factor that may not be directly correlated to the disease incidence, but may suggest of a long-term co-evolutionary latent infection interaction between CFPHV and its turtle-host across species. Finally, computational analysis of amino acid variants within the Turks and Caicos samples suggest potential functional importance in a substitution for marker UL18 that encodes the major capsid protein gene, which potentially could explain differences in pathogenicity. Nevertheless, such a theory remains to be validated by further research.

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