Harmonization of the English and Spanish versions of the NIH Toolbox Cognition Battery crystallized and fluid composite scores

OBJECTIVE

The National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) has both English- and Spanish-language versions producing crystallized and fluid cognition composite scores. This study examined measurement invariance between languages of administration. If established, measurement invariance would indicate that the composite scores measure the same construct across languages and provide scores that can be meaningfully compared and harmonized in future analyses.

METHOD

Participants from the NIHTB-CB normative sample included adults tested in English (n = 1,038; M = 49.1 years old, SD = 18.6) or Spanish (n = 408; M = 44.1 years old, SD = 16.7). Participants completed seven NIHTB-CB tests: Two measuring crystallized cognition and five measuring fluid cognition. Each test score was converted to an age-adjusted standard score or demographic-adjusted T score. A two-factor model (i.e., crystallized cognition and fluid cognition factors) was evaluated using confirmatory factor analysis. Measurement invariance was evaluated by fitting the two-factor model for each language of administration and constraining model parameters to be equivalent across languages, testing configural, weak, strong, and strict models.

RESULTS

For age-adjusted and demographic-adjusted scores, the two-factor model fit adequately well, and each factor had adequate reliability among English- and Spanish-speaking participants. Strict invariance was established across languages of administration for both age-adjusted and demographic-adjusted scores.

CONCLUSIONS

These findings support the harmonization of the English- and Spanish-language NIHTB-CB crystallized and fluid composite scores, indicating that the composite scores measure the same constructs on the same scale. The results support future studies merging data from participants evaluated in both languages. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Validity of the Verbal Naming Test and Boston Naming Test in a sample of older Veterans

ObjectiveThe Verbal Naming Test (VNT) assesses word-finding ability, or naming, through the use of a naming-to-definition paradigm and has been shown to effectively detect naming deficits in older adults. This study evaluated the convergent and discriminant validity of the VNT, assessed how well it detects Mild Cognitive Impairment (MCI), and provided descriptive data stratified by three levels of age (60-69, 70-79, 80-89).MethodThe sample included 151 healthy older Veterans who were found to be cognitively intact and free of neurological and acute psychiatric disorders (mean age = 74.23, SD = 6.67; range: 60-89) and 39 older Veterans with MCI (mean age = 72.97, SD = 8.24; range 60-88). Correlations were calculated between the VNT, Boston Naming Test (BNT), and several other neuropsychological measures. ROC analyses determined how well the VNT detected MCI.ResultsThe VNT correlated with the Rey Auditory Verbal Learning Test and the Logical Memory test. The BNT did not correlate with any measure with the exception of Judgment of Line Orientation (JLO). The Area Under the Curve (AUC) for the detection of MCI was 0.69. Normative data for the VNT are presented and stratified by ages.ConclusionsThis study provides evidence of the convergent and discriminant validity of the Verbal Naming Test in a sample of cognitively normal older adults, as well as its validity in the detection of MCI. It also provides descriptive data on the Verbal Naming Test that can be used in the neuropsychological assessment of older adults.

Screening for HIV-Associated Neurocognitive Disorders: Sensitivity and Specificity

HIV-associated neurocognitive disorder (HAND) remains prevalent among people living with HIV (PLWH), especially the mild forms, even those with well-controlled HIV. Recommendations from the literature suggest routine and regular screening for HAND to detect it early and manage it effectively and adjust treatments, if warranted, when present. However, screening for HAND is not routinely done, as there are no current guidelines on when to screen and which test or tests to use. Furthermore, many of the available screening tools for HAND often cannot accurately detect the mild forms of HAND and require highly trained healthcare professionals to administer and score the tests, a requirement that is not feasible for those low- and middle-income countries with the highest HIV incidence and prevalence rates. The purpose of this chapter was to review recent research on screening tests to detect HAND and report on the strengths, limitations, and psychometric properties of those tests to detect HAND.

Neurocognitive, psychiatric, and substance use characteristics in a diverse sample of persons with OUD who are starting methadone or buprenorphine/naloxone in opioid treatment programs

BACKGROUND

Medications for opioid use disorder such as opioid agonist treatment (OAT, including methadone, buprenorphine) are the gold standard intervention for opioid use disorder (OUD). Persons with OUD have high rates of neurocognitive impairment and psychiatric and substance use disorders, but few studies have examined these characteristics in diverse patients initiating OAT in opioid treatment programs (OTPs). Additionally, in these individuals, poor neurocognitive functioning and psychiatric/other substance use disorders are associated with poor OUD treatment outcomes. Given rapid changes in the opioid epidemic, we sought to replicate findings from our pilot study by examining these characteristics in a large diverse sample of persons with OUD starting OTP-based OAT.

METHODS

Ninety-seven adults with OUD (M age = 42.2 years [SD = 10.3]; M education = 11.4 years [SD = 2.3]; 27% female; 22% non-Hispanic white) were enrolled in a randomized longitudinal trial evaluating methadone versus buprenorphine/naloxone on neurocognitive functioning. All participants completed a comprehensive neurocognitive, psychiatric, and substance use evaluation within one week of initiating OAT.

RESULTS

Most of the sample met criteria for learning (79%) or memory (69%) impairment. Half exhibited symptoms of current depression, and comorbid substance use was highly prevalent. Lifetime cannabis and cocaine use disorders were associated with better neurocognitive functioning, while depression was associated with worse neurocognitive functioning.

CONCLUSIONS

Learning and memory impairment are highly prevalent in persons with OUD starting treatment with either methadone or buprenorphine/naloxone in OTPs. Depression and comorbid substance use are prevalent among these individuals, but neither impact learning or memory. However, depression is associated with neurocognitive impairment in other domains. These findings might allow clinicians to help persons with OUD starting OAT to develop compensatory strategies for learning and memory, while providing adjunctive treatment for depression. Trial Registration NCT, NCT01733693. Registered November 4, 2012, https://clinicaltrials.gov/ct2/show/NCT01733693 .

Underrepresentation of diverse populations and clinical characterization in opioid agonist treatment research: A systematic review of the neurocognitive effects of buprenorphine and methadone treatment

INTRODUCTION

The relative neurocognitive effects of the two most common opioid agonist treatments (OAT; buprenorphine and methadone) for opioid use disorder (OUD) are poorly understood. The aim of this systematic review is to examine the neurocognitive effects of OAT (buprenorphine and methadone) and the clinical and sociodemographic characteristics of study samples.

METHODS

The research team queried PubMed, PsycINFO and Cochrane Reviews for articles (01/1980-01/2020) with terms related to neurocognitive testing in adults (age ≥ 18) prescribed OAT. The team extracted neurocognitive data and grouped them by domain (e.g., executive functioning, learning/memory), and assessed study quality.

RESULTS

The search retrieved 2341 abstracts, the team reviewed 278 full articles, and 32 met inclusion criteria. Of these, 31 were observational designs and one was an experimental design. Healthy controls performed better across neurocognitive domains than OAT-treated persons (buprenorphine or methadone). Compared to those with active OUD, OAT-treated persons had better neurocognition in various domains. However, in seven studies comparing buprenorphine- and methadone-treated persons, buprenorphine was associated with better neurocognition than was methadone, with moderate to large effect sizes in executive functioning, attention/working memory, and learning/memory. Additionally, OAT research underreports clinical characteristics and underrepresents Black and Latinx adults, as well as women.

CONCLUSIONS

Findings suggest that compared to active opioid use, both buprenorphine and methadone treatment are associated with better neurocognitive functioning, but buprenorphine is associated with better executive functioning, attention/working memory, and learning/memory. These findings should be interpreted with caution given widespread methodological heterogeneity, and limited representation of ethnoracially diverse adults and women. Rigorous longitudinal comparisons with more diverse, better characterized samples will help to inform treatment and policy recommendations for persons with OUD.

A-157 Lexical-Semantic Analysis of Verbal Naming Test Performance in Older Adult Veterans

Objective

The Verbal Naming Test (VNT), a validated non-visual measure of word-finding ability in older adults, was designed to include words from distinct lexical (i.e., verbs vs. nouns) and semantic (i.e., action vs. object) categories to better capture various naming deficits. This study examined specific contributions of lexical and semantic categories to the convergent and discriminant validity of the VNT, and to how well it detects Mild Cognitive Impairment (MCI).

Method

The sample of older Veterans included 157 healthy controls (mean age = 74.23, SD = 6.67; range:60–89) and 39 diagnosed with MCI (mean age = 72.97, SD = 8.24; range:60–88). VNT item subscales were constructed for verbs/actions (ActionW) and nouns/objects presented either with (Obj+) or without (ObjW) an action component in the prompt. Correlations were calculated between VNT total/subscales and several other neuropsychological measures. ROC analyses compared relative contributions of each VNT subscale in detecting MCI.

Results

The ActionW subscale showed poor reliability (Cronbach’s alpha = 0.303) and did not correlate with any other measures. The ObjW, and Obj + subscales showed better reliability (Cronbach’s alpha>0.62) and correlated with age, measures of memory, and the Boston Naming Test. The Area Under the Curve (AUC) for detection of MCI was as follows: ActionW = 0.616; Obj + =0.635; ObjW = 0.689; and 50items = 0.690.

Conclusions

Lexical and semantic categories differentially affect VNT detection of MCI in older veterans. Object words, especially those without associated action components, provide the best measurement scale. Although still clinically relevant in detecting MCI, the poor reliability of verbs/action words suggests revising the VNT may improve its psychometric properties. Future research should replicate these results in a clinical sample.

Treatment with buprenorphine prior to EcoHIV infection of mice prevents the development of neurocognitive impairment

Approximately 15-40% of people living with HIV develop HIV-associated neurocognitive disorders, HAND, despite successful antiretroviral therapy. There are no therapies to treat these disorders. HIV enters the CNS early after infection, in part by transmigration of infected monocytes. Currently, there is a major opioid epidemic in the United States. Opioid use disorder in the context of HIV infection is important because studies show that opioids exacerbate HIV-mediated neuroinflammation that may contribute to more severe cognitive deficits. Buprenorphine is an opioid derivate commonly prescribed for opiate agonist treatment. We used the EcoHIV mouse model to study the effects of buprenorphine on cognitive impairment and to correlate these with monocyte migration into the CNS. We show that buprenorphine treatment prior to mouse EcoHIV infection prevents the development of cognitive impairment, in part, by decreased accumulation of monocytes in the brain. We propose that buprenorphine has a novel therapeutic benefit of limiting the development of neurocognitive impairment in HIV-infected opioid abusers as well as in nonabusers, in addition to decreasing the use of harmful opioids. Buprenorphine may also be used in combination with HIV prevention strategies such as pre-exposure prophylaxis because of its safety profile.

Demographically-adjusted norms for the processing speed subtests of the WAIS-III in a Spanish-speaking adult population: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project

OBJECTIVE

The Wechsler Adult Intelligence Scale (WAIS) processing speed subtests are among the most ubiquitous indices of processing speed in the field. The aim of this study was to develop and examine demographically-adjusted normative data for Spanish language versions of the WAIS-III Digit Symbol Coding (DSC) and Symbol Search (SS) subtests for US-dwelling Spanish-speakers living in the US/Mexico border region.

METHODS

The sample included 203 healthy participants who were part of the larger Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project (DSC: n = 201; SS: n = 200).

RESULTS

Older age and higher education were both related to lower scores on the DSC and SS subtests (all ps < .0001). There were no significant effects for gender (all ps > .05). Raw-to-scaled score conversions were calculated for both subtests, and fractional polynomial equations were derived to compute demographically-adjusted T-scores accounting for age, education, and gender for each subtest and the Processing Speed Index. Published norms for English-speaking non-Hispanic white adults slightly overestimated impairment rates (T-scores <40) on both the DSC and SS subtests, while the norms for English-speaking non-Hispanic Black/African Americans and the new NP-NUMBRS norms Spanish-speakers both yielded impairment rates that fell within expected limits for healthy controls (i.e. 13%-14%).

CONCLUSIONS

This study suggests that population-specific normative data can improve the diagnostic validity of these measures for U.S.-dwelling Spanish-speakers living in the US/Mexico border region. Future research is needed to investigate the utility of these norms for other U.S.-dwelling Spanish-speaking subpopulations (e.g. Caribbean, Central American, South American).

The Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project: Overview and considerations for life span research and evidence-based practice

OBJECTIVE

This paper summarizes the findings of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project and offers a roadmap for future research.

METHODS

The NP-NUMBRS project represents the largest and most comprehensive co-normed neuropsychological battery to date for native Spanish-speaking healthy adults from the U.S. (California/Arizona)-Mexico borderland region (N = 254; ages 19-60 years). These norms provide demographic adjustments for tests across numerous domains (i.e., verbal fluency, processing speed, attention/working memory, executive function, episodic memory [learning and delayed recall], visuospatial, and fine motor skills).

CONCLUSIONS

This project: 1) shows that the NP-NUMBRS norms consistently outperformed previously published norms for English-speaking non-Hispanic (White and African-American) adults in identifying impairment; 2) explores the role of Spanish-English bilingualism in test performance; and 3) provides support for the diagnostic validity of these norms in detecting HIV-associated neurocognitive impairment. Study limitations include the limited assessment of sociocultural variables and generalizability (e.g., other Latina/o populations, age limit [19 - 60 years]). Future research is needed to: 1) investigate these norms with U.S.-dwelling Spanish-speakers of non-Mexican heritage and other clinical subpopulations; 2) expand coverage of cognitive domains (e.g. language, visuospatial); 3) develop large normative datasets for children and older Latina/o populations; 4) examine how sociocultural factors impact performance (e.g., bilingualism, acculturation); 5) investigate these norms' diagnostic and ecological validity; and 6) develop norms for neurocognitive change across time. It is hoped that the NP-NUMBRS norms will aid researchers and clinicians working with U.S.-dwelling Spanish-speakers from the U.S.-Mexico borderland to conduct research and evidence-based neuropsychological evaluations in a more culturally responsive and ethical manner.

The state of neuropsychological test norms for Spanish-speaking adults in the United States

Objective: The present review paper aimed to identify published neuropsychological test norms developed for Spanish-speakers living in the United States (U.S.). Methods: We conducted a systematic review of the literature via an electronic search on PubMed using keywords "Normative data," "Neuropsychological test," "norms", "Hispanic/Latinos," "Spanish Speakers," and "United States." We added other studies and published manuals as identified by citations in papers from the original search. Results Eighteen sources of normative data for Spanish-speakers in the U.S. were identified. Of the 18 citations identified, only four provide normative data on comprehensive batteries of tests for Spanish-Speakers. Two of these are based on persons living in the southwest of the U.S., who tend to be of Mexican origin. Overall, a number of the studies are focused on older persons and although the majority include participants with wide ranges of education, participants in the ends of the education distribution tend to be underrepresented. Conclusion: Here we provide a detailed description of the neuropsychological normative data currently available for Spanish-speakers living in the U.S. While there has been increased attention towards developing norms for neuropsychological batteries in Spanish-speaking countries (e.g., Latin America and Spain), there is still an urgent need to standardize neuropsychological tests among diverse groups of Spanish-speaking adults living in the U.S. The present review presents a list of norms for U.S.-dwelling Spanish-speakers, thus providing an important tool for clinicians and researchers.

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.

Dyadic Group Exercises for Persons with Memory Deficits and Care Partners: Mixed-Method Findings from the Paired Preventing Loss of Independence through Exercise (PLIÉ) Randomized Trial

Background: Non-pharmacological therapies for persons with dementia (PWD) are needed. Objective: To develop and test the Paired Preventing Loss of Independence through Exercise (PLIÉ) program, an integrative group movement program for PWD and care partners (CPs). Methods: Participants were randomized to immediate or delayed start to Paired PLIÉ in community-based classes (1 hour, 2 days/week, 12 weeks, 3 home visits). Co-primary outcomes included standard measures of cognition, physical function,and quality of life (PWD) and caregiver burden (CPs) assessed by blinded assessors, analyzed using linear mixed models to calculate effect sizes for outcome changes during Paired PLIÉ, controlling for randomization group. Anonymous satisfaction surveys included satisfaction ratings and thematic analysis of open-ended responses. Results: Thirty dyads enrolled, 24 (80%) completed. PWD (mean age 80; 55% female) experienced significant improvement in self-rated quality of life (Effect Size+0.23; p = 0.016) when participating in Paired PLIÉ, while CPs experienced a non-significant increase in burden (–0.23, p = 0.079). Changes in physical and cognitive function in PWD were not significant. All CPs returning the satisfaction survey (n = 20) reported being moderately-to-highly satisfied with the program. Thematic analyses identified physical (e.g., sit-to-stand, more energy), emotional (enjoyment), and social benefits (peer-to-peer interaction) for PWD and CPs; challenges were primarily related to getting to the in-person classes. Conclusion: Paired PLIÉ is a promising integrative group movement program that warrants further study. It is feasible and may improve self-rated quality of life in PWD. Although CPs may experience increased burden due to logistical challenges, most reported high satisfaction and physical, emotional, and social benefits.

Introduction to the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project

OBJECTIVE

The present introduction to the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project aims to provide an overview of the conceptual framework and rationale that guided the development of this project.

METHODS

We describe important aspects of our conceptual framework, which was guided by some of the main purposes of neuropsychological testing, including the identification of underlying brain dysfunction, and the characterization of cognitive strengths and weakness relevant to everyday functioning. We also provide our rationale for focusing this norm development project on Spanish-speakers in the United States, and provide an outline of the articles included in this Special Issue focused on the NP-NUMBRS project.

CONCLUSIONS

The data presented in this Special Issue represent an important tool for clinicians and researchers working in the neuropsychological assessment of Spanish-speakers in the United States.

Demographically-adjusted norms for the WAIS-R Block Design and Arithmetic subtests: Results from the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project

OBJECTIVE

Wechsler Adult Intelligence Scale (WAIS) Block Design and Arithmetic subtests are frequently used as measures of visuospatial construction and verbal working memory, respectively. As part of a larger test adaptation and norming effort for this population, we generated and investigated demographically-adjusted interpretive norms for WAIS-R Block Design and Arithmetic in Spanish-speaking adults living in the US-Mexico border region.

METHOD

Participants included 183 community-dwelling adults ages 20-55 (education range: 0-20 years; 58% women) from the NeuroPsychological-Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) Project. They completed the WAIS-R Block Design and Arithmetic subtests in Spanish. Demographically-adjusted T-scores were calculated for these subtests using fractional polynomial equations adjusting for linear and non-linear effects of age, education (continuous), and sex. We compared our rates of impairment (i.e. T < 40) against rates calculated using published English-speaking WAIS-R standardization sample norms adjusted for age, education, and sex.

RESULTS

Education was positively associated with performance on Block Design and Arithmetic subtests, and men outperformed women on both subtests. The present Spanish-speaker norms for these subtests yielded expected rates of "impairment" (i.e. 15-16% impaired, a 1 SD cutoff), while existing norms for English-speakers underestimated impairment (i.e. 5-6% impaired) when applied to our Spanish-speaking sample.

CONCLUSIONS

Regional normative data will improve interpretation of test performance on Block Design and Arithmetic subtests for Spanish-speakers living in the US-Mexico border region and may aid in bolstering the overall analysis of neuropsychological profile patterns in this population. Cross-validation with Spanish-speakers in other regions and/or with other national origins is needed.

Home-versus acquired-language test performance on the Hopkins Verbal Learning Test-Revised among multilingual South Africans

The Hopkins Verbal Learning Test-Revised (HVLT-R) has been adapted for use in many different languages and in low- and middle-income countries. However, few adaptations have evaluated performance differences between home- and acquired-language administrations. The present study examined performance on an adapted HVLT-R between multilingual South Africans who chose to be tested in a home or acquired language. The HVLT-R was administered to 112 multilingual, isiXhosa as home language, Black South African adults (49% men) with no major medical, neurological, or psychiatric problems. Sixty-one preferred to take the test in isiXhosa and 51 preferred English. We examined between-language differences in word equivalency, primary scores, learning indices, and serial position effects. We also examined language, age, education, and gender on test performance. English-examinees were significantly younger and more educated than isiXhosa-examinees (p's < .05). Although isiXhosa words had more letters and syllables than English words (p's <.001), there were no significant differences between groups on HVLT-R performance or serial recall (p's > .05). More education and being a woman predicted better Total and Delayed Recall (p's<.05). Performance on this modified HVLT-R appears similar between English and isiXhosa administrations among South African isiXhosa first language speakers, which makes comparisons between preferred language administrations appropriate.

B-Vitamin Therapy for Kidney Transplant Recipients Lowers Homocysteine and Improves Selective Cognitive Outcomes in the Randomized FAVORIT Ancillary Cognitive Trial

BACKGROUND

Objectives: Elevated plasma total homocysteine (tHcy) is associated with increased risk of cardiovascular disease, stroke and dementia. Results of clinical trials using B-vitamins to reduce the cognitive risks attributed to tHcy have been inconsistent. The high prevalence of both hyperhomocysteinemia and cognitive impairment among kidney transplant recipients makes them an important population in which to evaluate the effect of lowering homocysteine on cognitive function. We therefore evaluated whether B-vitamin therapy to lower tHcy would prevent cognitive-decline in a cohort of stable kidney transplant recipients.

DESIGN

The study was a longitudinal ancillary of the FAVORIT trial, a randomized, placebo-controlled multi-site trial of high-dose B vitamins to reduce cardiovascular and cerebrovascular events in clinically stable kidney transplant recipients with elevated tHcy.

PARTICIPANTS

584 participants from 18 sites across North America.

INTERVENTION

The intervention consisted of a daily multivitamin containing high-doses of folate (5.0 mg), vitamin B12 (1.0 mg) and vitamin B6 (50 mg). The placebo consisted of a daily multi-vitamin containing no folate and recommended daily allowances of vitamins B12 and B6 (0 mg folate; 2.0 µg vitamin B12; 1.4 mg vitamin B6).

MEASUREMENTS

Annual neuropsychological assessment for up to 5 years (mean 3.3 years) using a standardized test battery. Efficacy was analyzed on an intention-to-treat basis using end-of-trial data. Subgroup analyses included stratification for baseline plasma B-vitamin and tHcy concentrations.

RESULTS

At baseline, cognitive impairment was common with 61% of participants falling more than one standard deviation below published norms for at least one cognitive test. Fewer than 1% of participants had insufficient plasma folate < 5 ng/ml or vitamin B12 < 148 pmol/L. However, 44.6% had plasma B6 concentrations < 30 nmol/L. At follow-up, processing speed and memory scores were modestly but significantly better in the B-vitamin supplement group than in controls (p≤0.05). There was no interaction between baseline tHcy, B-vitamin status and treatment on the cognitive outcomes.

CONCLUSIONS

High-dose B-vitamin supplementation provided modest cognitive benefit for kidney transplant recipients with elevated baseline tHcy. Since nearly all participants were folate and vitamin B12 sufficient at baseline, the potential cognitive benefits of folate and B12 supplementation in individuals with poor B-vitamin status remains to be determined.

Machine learning as a new paradigm for characterizing localization and lateralization of neuropsychological test data in temporal lobe epilepsy

In this study, we employed a kernel support vector machine to predict epilepsy localization and lateralization for patients with a diagnosis of epilepsy (n = 228). We assessed the accuracy to which indices of verbal memory, visual memory, verbal fluency, and naming would localize and lateralize seizure focus in comparison to standard electroencephalogram (EEG). Classification accuracy was defined as models that produced the least cross-validated error (CVϵ). In addition, we assessed whether the inclusion of norm-based standard scores, demographics, and emotional functioning data would reduce CVϵ. Finally, we obtained class probabilities (i.e., the probability of a particular classification for each case) and produced receiver operating characteristic (ROC) curves for the primary analyses. We obtained the least error assessing localization data with the Gaussian radial basis kernel function (RBF; support vectors = 157, CVϵ = 0.22). There was no overlap between the localization and lateralization models, such that the poorest localization model (the hyperbolic tangent kernel function; support vectors = 91, CVϵ = 0.36) outperformed the strongest lateralization model (RBF; support vectors = 201, CVϵ = 0.39). Contrary to our hypothesis, the addition of norm, demographics, and emotional functioning data did not improve the accuracy of the models. Receiver operating characteristic curves suggested clinical utility in classifying epilepsy lateralization and localization using neuropsychological indicators, albeit with better discrimination for localizing determinations. This study adds to the existing literature by employing an analytic technique with inherent advantages in generalizability when compared to traditional single-sample, not cross-validated models. In the future, class probabilities extracted from these and similar analyses could supplement neuropsychological practice by offering a quantitative guide to clinical judgements.

A Mobile App to Screen for Neurocognitive Impairment: Preliminary Validation of NeuroScreen Among HIV-Infected South African Adults

Background

Neurocognitive impairment (NCI) is one of the most common complications of HIV infection, and has serious medical and functional consequences. South Africa has 7 million people living with HIV (PLHIV) with up to three-quarters of antiretroviral therapy (ART)-naïve individuals having NCI. South Africa’s health system struggles to meet the care needs of its millions of PLHIV; screening for NCI is typically neglected due to limited clinical staff trained to administer, score, and interpret neuropsychological tests, as well as long test batteries and limited screening tools for South African populations. Without accurate, clinically useful, and relatively brief NCI screening tests that can be administered by all levels of clinical staff, critical opportunities to provide psychoeducation, behavioral planning, additional ART adherence support, and adjuvant therapies for NCI (when they become available) are missed. To address these challenges and gap in care, we developed an mHealth app screening tool, NeuroScreen, to detect NCI that can be administered by all levels of clinical staff, including lay health workers.

Objective

The purpose of this study was to examine sensitivity and specificity of an adapted version of NeuroScreen to detect NCI (as determined by a gold standard neuropsychological test battery administered by a trained research psychometrist) among HIV-infected South Africans when administered by a lay health worker.

Methods

A total of 102 HIV-infected black South African adults who had initiated ART at least 12 months prior were administered NeuroScreen and a gold standard neuropsychological test battery in the participants’ choice of language (ie, English or isiXhosa). Three composite z scores were calculated for NeuroScreen: (1) sum of all individual test scores, (2) sum of all individual test scores and error scores from four tests, and (3) sum of four tests (abbreviated version). Global deficit scores were calculated for the gold standard battery where a score of 0.5 or greater indicated the presence of NCI.

Results

The mean age of participants was 33.31 (SD 7.46) years, most (59.8%, 61/102) had at least 12 years of education, and 81.4% (83/102) of the sample was female. Gold standard test battery results indicated that 26.5% (27/102) of the sample had NCI. Sensitivity and specificity of age-, education-, and sex-adjusted NeuroScreen scores were 81.48% and 74.67% for composite score 1, 81.48% and 81.33% for composite score 2, and 92.59% and 70.67% for composite score 3, respectively.

Conclusions

NeuroScreen, a highly automated, easy-to-use, tablet-based screening test to detect NCI among English- and isiXhosa-speaking South African HIV patients demonstrated robust sensitivity and specificity to detect NCI when administered by lay health workers. NeuroScreen could help make screening for NCI more feasible. However, additional research is needed with larger samples and normative test performance data are needed.

Neuropsychological function is improved among opioid dependent adults who adhere to opiate agonist treatment with buprenorphine-naloxone: a preliminary study

BACKGROUND

Among persons with opioid use disorder (OUD), neuropsychological dysfunction is associated with depression, and better neuropsychological function is associated with opioid abstinence. However, it is unknown whether depressive symptomatology or adherence to opiate agonist treatment are associated with neuropsychological change over time.

METHODS

We recruited 20 buprenorphine/naloxone-treated adults with OUD (M Age = 45.2 years [SD = 8.1]; 25% female) to complete baseline and 6 month visits containing a neuropsychological test battery and self-reported measures of depressive symptomatology and medication adherence.

RESULTS

Depressive symptomatology was not significantly related to neuropsychological change (p's > .05). Greater adherence to buprenorphine/naloxone was associated with improvements in learning, memory, and global functioning (r's = .52-60; p's < .05).

CONCLUSIONS

Among OUD patients, greater adherence to buprenorphine/naloxone is associated with improved neuropsychological functioning over time. In contrast, depressive symptomatology is not associated with neuropsychological functioning over time. Supporting adherence to buprenorphine/naloxone may improve and/or preserve learning and memory functioning in individuals treated for OUD.

TRIAL REGISTRATION

NCT01108679 . Registered 21 April 2010.

The Combined Roles of Nonsomatic Depressive Symptomatology, Neurocognitive Function, and Current Substance Use in Medication Adherence in Adults Living With HIV Infection

Depression, global neurocognitive (GNC) function, and substance use disorders (SUDs) are each associated with medication adherence in persons living with HIV (PLWH). Because somatic symptoms can inflate depression scores in PLWH, the role of nonsomatic depressive symptomatology (NSDS) should be considered in adherence. However, the combined roles of NSDS, GNC function, and current SUDs in predicting combined antiretroviral therapy (cART) adherence remain poorly understood. Forty PLWH (70% Latina/o; 30% non-Hispanic White) completed psychiatric/SUD, neurocognitive, and self-report cART adherence evaluations. Higher NSDS was associated with suboptimal adherence (p < .01), but optimal and suboptimal adherers did not differ in GNC function or current SUDs. Only NSDS was associated with suboptimal adherence, after accounting for GNC function and SUDs (p = .01). NSDS uniquely predicted self-reported adherence, beyond GNC function and current SUDs among ethnically diverse PLWH. Methodological issues between present and prior studies should also be considered.

Daily Activity Abilities in MCI, Alzheimer's Disease, and Healthy Controls

Mild cognitive impairment (MCI) is a risk state for dementia. The present study assessed daily functioning in MCI individuals (amnestic [aMCI] and nonamnestic [naMCI]) relative to those with Alzheimer's disease (AD) and healthy controls (NC). Twenty AD participants, 14 aMCI, 12 naMCI, and 30 healthy controls were administered the Direct Assessment of Functional Status (DAFS). The AD group performed poorer than all groups on all DAFS subscales. The aMCI group performed poorer than controls on the shopping subtests, while the naMCI group performed poorer than controls on only the free recall shopping. Finally, DAFS subscales discriminated the AD and aMCI groups well, but only recognition shopping discriminated between naMCI and aMCI individuals. These findings suggest that circumscribed ADL deficits distinguish subtypes of MCI and AD.

Indicator microbes correlate with pathogenic bacteria, yeasts and helminthes in sand at a subtropical recreational beach site

AIMS

Research into the relationship between pathogens, faecal indicator microbes and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non-point source subtropical marine beach.

METHODS AND RESULTS

In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analysed over the course of 6 days for several pathogens, microbial source tracking markers and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use.

CONCLUSIONS

Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts and the bacterial pathogen Staphylococcus aureus including methicillin-resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non-point source beaches.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non-point sources beaches.

25-Hydroxyvitamin D, dementia, and cerebrovascular pathology in elders receiving home services

BACKGROUND

Vitamin D deficiency has potential adverse effects on neurocognitive health and subcortical function. However, no studies have examined the association between vitamin D status, dementia, and cranial MRI indicators of cerebrovascular disease (CVD).

METHODS

Cross-sectional investigation of 25-hydroxyvitamin D [25(OH)D], dementia, and MRI measures of CVD in elders receiving home care (aged 65-99 years) from 2003 to 2007.

RESULTS

Among 318 participants, the mean age was 73.5 +/- 8.1 years, 231 (72.6%) were women, and 109 (34.3%) were black. 25(OH)D concentrations were deficient (<10 ng/mL) in 14.5% and insufficient (10-20 ng/mL) in 44.3% of participants. There were 76 participants (23.9%) with dementia, 41 of which were classified as probable AD. Mean 25(OH)D concentrations were lower in subjects with dementia (16.8 vs 20.0 ng/mL, p < 0.01). There was a higher prevalence of dementia among participants with 25(OH)D insufficiency (< or =20 ng/mL) (30.5% vs 14.5%, p < 0.01). 25(OH)D deficiency was associated with increased white matter hyperintensity volume (4.9 vs 2.9 mL, p < 0.01), grade (3.0 vs 2.2, p = 0.04), and prevalence of large vessel infarcts (10.1% vs 6.9%, p < 0.01). After adjustment for age, race, sex, body mass index, and education, 25(OH)D insufficiency (< or =20 ng/mL) was associated with more than twice the odds of all-cause dementia (odds ratio [OR] = 2.3, 95% confidence interval [CI] 1.2-4.2), Alzheimer disease (OR = 2.5, 95% CI 1.1-6.1), and stroke (with and without dementia symptoms) (OR = 2.0, 95% CI 1.0-4.0).

CONCLUSIONS

Vitamin D insufficiency and deficiency was associated with all-cause dementia, Alzheimer disease, stroke (with and without dementia symptoms), and MRI indicators of cerebrovascular disease. These findings suggest a potential vasculoprotective role of vitamin D.

Simultaneous concentration of Enterococci and coliphage from marine waters using a dual layer filtration system

Concentrating diverse microbes in a time and cost effective manner is an essential component in water quality monitoring of recreational beaches. Historically, detection of bacteria and viruses requires two different capture methods to detect both types of organisms in a given water sample. The purpose of this present study was to evaluate a newly devised dual layered filtration system, which was developed to simultaneously concentrate both viruses and bacteria in one step from marine waters. An apparatus was designed to accommodate two 90-mm diam., 0.45 microm pore size membranes in series, one on top of the other. The top polyvinylidene fluoride (PVDF) membrane was used to filter bacteria by physical straining while the bottom HA membrane retained viruses through adsorption. Results indicated that the dual layer filtration system recovered 83+/-14% of the test bacteria (Enterococcus fecalis) and 81+/-28% of the test virus (MS2 coliphage) on the top and bottom membranes, respectively. This research demonstrates the potential of using a dual layered filtration system for the simultaneous concentration of both bacteria and viruses on separate filters from recreational beach waters. This system is relatively simple to use, inexpensive, and has the potential to be suitable for routine monitoring. This study serves as a proof of concept for the technique. Additional experiments are needed to evaluate the system on a variety of different bacteria and viruses as well as on water with different physical and chemical parameters.

Confirmation of putative stormwater impact on water quality at a Florida beach by microbial source tracking methods and structure of indicator organism populations

The effect of a stormwater conveyance system on indicator bacteria levels at a Florida beach was assessed using microbial source tracking methods, and by investigating indicator bacteria population structure in water and sediments. During a rain event, regulatory standards for both fecal coliforms and Enterococcus spp. were exceeded, contrasting with significantly lower levels under dry conditions. Indicator bacteria levels were high in sediments under all conditions. The involvement of human sewage in the contamination was investigated using polymerase chain reaction (PCR) assays for the esp gene of Enterococcus faecium and for the conserved T antigen of human polyomaviruses, all of which were negative. BOX-PCR subtyping of Escherichia coli and Enterococcus showed higher population diversity during the rain event; and higher population similarity during dry conditions, suggesting that without fresh inputs, only a subset of the population survives the selective pressure of the secondary habitat. These data indicate that high indicator bacteria levels were attributable to a stormwater system that acted as a reservoir and conduit, flushing high levels of indicator bacteria to the beach during a rain event. Such environmental reservoirs of indicator bacteria further complicate the already questionable relationship between indicator organisms and human pathogens, and call for a better understanding of the ecology, fate and persistence of indicator bacteria.

Multivitamin use and B vitamin status in a homebound elderly population

OBJECTIVE

Homebound elderly are at increased risk for micronutrient deficiencies and nutritional status in this population has not been adequately described. There is evidence for beneficial effects of multivitamin use and a greater understanding of their nutritional contribution could identify behaviors that may help alleviate excess chronic disease. The purpose of this analysis is to investigate, in a racially diverse group of homebound elders, the association of multivitamin use with measures of plasma B vitamin concentrations.

DESIGN

We examined the cross-sectional association between multivitamin use and plasma concentrations of B vitamins and homocysteine in 236 white and 182 black homebound elders (65-99y). Dietary intake was assessed and demographic and health information was ascertained.

RESULTS

White and black elders had a high prevalence of dietary intakes below the Estimated Average Requirement for folate (38.1 and 40.7%), vitamin B6 (16.9 and 19.2%.), and vitamin B12 (3 and 3.9%) respectively. Multivitamin use was associated with higher mean plasma B vitamin concentrations in each group. In whites, multivitamin users had higher concentrations of vitamin B6 (64.6 vs. 32.4 nmol/L; p < 0.001), vitamin B12 (398 vs. 324 pmol/L;p < 0.001) and folate (39.4 vs. 30.4 nmol/L;p < 0.001). Black multivitamin users had higher concentrations of vitamin B6 (53.7 vs. 29.5 nmol/L; p < 0.001), B12 (427 vs. 372 pmol/L; p < 0.05) and folate (35.7 vs. 25.4 nmol/L; < 0.001) than non-users.

CONCLUSIONS

Multivitamin supplementation was associated with higher mean plasma concentrations of vitamins B6, B12, and folate and lower prevalence of low plasma B vitamin status in a biracial homebound elderly.

Geographical variation in antibiotic resistance profiles of Escherichia coli isolated from swine, poultry, beef and dairy cattle farm water retention ponds in Florida1

AIMS

The aim of this study was to assess geographical variation in multiple antibiotic resistance (MAR) profiles of livestock Escherichia coli as well as to evaluate the ability of MAR profiles to differentiate sources of faecal pollution.

METHODS AND RESULTS

More than 2000 E. coli isolates were collected from water retention ponds and manure of swine, poultry, beef and dairy farms in south, central and north Florida, and analysed for MAR using nine antibiotics. There were significant differences in antibiotic resistance of E. coli by season and livestock type for more than one antibiotic, but regional differences were significant only for ampicillin. Over the three regions, discriminant analysis using MAR profiles correctly classified 27% of swine, 49% of poultry, 56% of beef and 51% of dairy isolates.

CONCLUSIONS

Regional variations in MAR combined with moderate discrimination success suggest that MAR profiles of E. coli may only be marginally successful in identifying sources of faecal pollution.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the existence of regional and seasonal differences in MAR profiles as well as the limited ability of MAR profiles to discriminate among livestock sources.

Assessment of virulence-factor activity relationships (VFARs) for waterborne diseases

Virulence-factor activity relationship (VFAR) is a concept that was developed as a way to relate the architectural and biochemical components of a microorganism to its potential to cause human disease. Development of these relationships requires specialised bioinformatics databases that do not exist at present. A pilot-scale VFAR database was designed for three different waterborne organisms: Escherichia coli, Norovirus and Cryptosporidium, to evaluate VFAR relationships. For the web-based database, each organism has separate pages containing virulence genes, occurrence genes, primer sets and probes, taxonomy, outbreaks, and serotype/species/genogroup/genotype. As the database continues to grow, it will be possible to relate the occurrence and prevalence of certain genes in various microorganisms to outbreak data and, subsequently, to establish the utility of using a combination of specific genes as markers of virulence and in establishing virulence-factor activity relationships (VFARs). The database and the VFARs established will be of use to the regulatory community as a way to assist with prioritising those organisms, which need to be regulated.

Assessment of methods for detection of infectious Cryptosporidium oocysts and Giardia cysts in reclaimed effluents

This study evaluates the occurrence of Cryptosporidium oocysts and Giardia cysts in reclaimed effluents if method 1623 with the Envirochek capsule filters (standard and high-volume [HV] filters) and a modified version of the Information Collection Rule method (ICR) with the polypropylene yarn-wound cartridge filter are used. The recovery efficiency of the analytical methods was evaluated with samples of reagent, tap, and reclaimed water by using flow cytometer-sorted spike suspensions. (Oo)cyst recovery efficiency determined filter performance and method reproducibility in the water matrix tested. Method 1623 with the Envirochek HV capsule filter generated significantly higher recovery rates than did the standard Envirochek filter and the modified ICR method. Notwithstanding, large variations in recovery rates (>80%) occurred with samples of reclaimed water, and none of the water quality parameters analyzed in the reclaimed effluents could explain such variability. The highest concentrations of indigenous oocysts were detected by method 1623 with the HV filter, which provided a sufficient number of oocysts for further confirmation of infectious potential. Confirmation of species and potential infectivity for all positive protozoan samples was made by using a nested PCR restriction fragment polymorphism assay and the focus detection method most-probable-number assay, respectively. The methodology and results described in the present investigation provide useful information for the establishment of pathogen numeric standards for reclaimed effluents used for unrestricted irrigation.

Elution, detection, and quantification of polio I, bacteriophages, Salmonella montevideo, and Escherichia coli O157:H7 from seeded strawberries and tomatoes

This study compared the effect of different physical and chemical treatments of strawberries and tomatoes to determine their ability to recover seeded viral and bacterial pathogens from produce surfaces. Solutions of salts, amino acids, complex media, and detergents were compared as eluants. Phosphate-buffered saline (PBS) containing 0.1% Tween 80 eluted the highest number of seeded microorganisms. Elution with this defined solution was then compared under different conditions of physical agitation. Rotary shaking for 20 min at 36 degrees C eluted higher numbers of viruses and bacteria than did low- or high-speed stomaching. Commercially available and laboratory prepared bacteriological differential media were compared for their ability to recover and distinguish eluted Salmonella Montevideo and Escherichia coli O157:H7 strains from seeded produce. The recovery of seeded bacterial pathogens was low when differential media containing selective ingredients were used (MacConkey sorbitol agar, XLD agar, MacConkey agar). Highest recoveries were obtained on a medium consisting of tryptic soy agar supplemented with sodium thiosulfate and ferric ammonium citrate compared with selective media that inhibited up to 50% of the growth of the eluted microorganisms.

Influence of salts on virus adsorption to microporous filters

We investigated the direct and indirect effects of mono-, di-, and trivalent salts (NaCl, MgCl(2), and AlCl(3)) on the adsorption of several viruses (MS2, PRD-1, phiX174, and poliovirus 1) to microporous filters at different pH values. The filters studied included Millipore HA (nitrocellulose), Filterite (fiberglass), Whatman (cellulose), and 1MDS (charged-modified fiber) filters. Each of these filters except the Whatman cellulose filters has been used in virus removal and recovery procedures. The direct effects of added salts were considered to be the effects associated with the presence of the soluble salts. The indirect effects of the added salts were considered to be (i) changes in the pH values of solutions and (ii) the formation of insoluble precipitates that could adsorb viruses and be removed by filtration. When direct effects alone were considered, the salts used in this study promoted virus adsorption, interfered with virus adsorption, or had little or no effect on virus adsorption, depending on the filter, the virus, and the salt. Although we were able to confirm previous reports that the addition of aluminum chloride to water enhances virus adsorption to microporous filters, we found that the enhanced adsorption was associated with indirect effects rather than direct effects. The increase in viral adsorption observed when aluminum chloride was added to water was related to the decrease in the pH of the water. Similar results could be obtained by adding HCl. The increased adsorption of viruses in water at pH 7 following addition of aluminum chloride was probably due to flocculation of aluminum, since removal of flocs by filtration greatly reduced the enhancement observed. The only direct effect of aluminum chloride on virus adsorption that we observed was interference with adsorption to microporous filters. Under conditions under which hydrophobic interactions were minimal, aluminum chloride interfered with virus adsorption to Millipore, Filterite, and 1MDS filters. In most cases, less than 10% of the viruses adsorbed to filters in the presence of a multivalent salt and a compound that interfered with hydrophobic interactions (0.1% Tween 80 or 4 M urea).

Vascular innervation in atherogenesis

Although collar-induced atherosclerosis continues to be used as an investigative tool, the underlying mechanism has not been established. Two primary mechanisms suggested are adventitial ischemia due to reduction in vasa vasorum, and perivascular denervation. We have examined the effect of injuring the common carotid artery in the pattern produced by the ends of a silastic collar, and have correlated the effect on innervation with change in intima/media ratios in normal and cholesterol-fed rabbits. The serum cholesterol of cholesterol-fed rabbits was significantly elevated by 10 days following initiation of cholesterol feeding, and further elevated at 21 days. No structural difference was detected between the uninjured carotid arteries of control and cholesterol-fed rabbits. At the site of injury in freeze injured carotid arteries there was a thickening of the intima which was increased in cholesterol-fed rabbits. The intima at the site of injury was composed of lipid-laden cells embedded in a matrix of collagen and elastin fibres. In carotid artery segments, between two sites of freeze injury, denervation was established by immunohistochemistry and electron microscopy. The denervated segments were not morphologically different from uninjured carotid arteries in either control or cholesterol-fed rabbits. While injury induced intimal thickening and foam cell development, denervation did not. It is concluded that perivascular denervation is a consequence of silastic collar application and is not involved in the induction of atherosclerosis.

Dynamic susceptibility contrast MR imaging of regional cerebral blood volume in Alzheimer disease: a promising alternative to nuclear medicine

BACKGROUND AND PURPOSE

The goal of our study was to evaluate the sensitivity and specificity for Alzheimer disease of semiquantitative dynamic susceptibility contrast (DSC) MR imaging as compared with results of qualitative single-photon emission computed tomography (SPECT) in the same patients and with previously published semiquantitative SPECT results.

METHODS

Fifty subjects were studied: 19 patients with probable Alzheimer disease with moderate cognitive impairment, eight mildly impaired patients with possible or probable Alzheimer disease, 18 group-matched elderly healthy comparison subjects, and five elderly comparison patients with psychiatric diagnoses. Relative values of temporoparietal regional cerebral blood volume (rCBV) were measured as a percentage of cerebellar rCBV, and group classification was assessed with logistic regression. The DSC MR imaging results were compared with SPECT scans in these same subjects and with previously published semiquantitative SPECT data.

RESULTS

Temporoparietal rCBV ratios were reduced 20% bilaterally in the patients with Alzheimer disease. Using left and right temporoparietal rCBV as index measures, sensitivity was 95% in moderately affected patients with Alzheimer disease and 88% in patients with mild cases. Specificity was 96% in healthy comparison subjects and in psychiatric comparison subjects. Sensitivity with DSC MR imaging was considerably better than with visual clinical readings of SPECT scans (74% in moderate and 50% in mild Alzheimer disease cases), and was similar to previous published SPECT temporoparietal measurements (90%). Specificity with SPECT was 100% visually and 87% based on previous temporoparietal measurements.

CONCLUSIONS

DSC MR imaging of rCBV is promising as a safe, potentially lower-cost alternative to nuclear medicine imaging for the evaluation of patients with dementia.

Isolation of an amoeba naturally harboring a distinctive Legionella species

There are numerous in vitro studies documenting the multiplication of Legionella species in free-living amoebae and other protozoa. It is believed that protozoa serve as host cells for the intracellular replication of certain Legionella species in a variety of environmental settings. This study describes the isolation and characterization of a bacterium initially observed within an amoeba taken from a soil sample. In the laboratory, the bacterium multiplied within and was highly pathogenic for Acanthamoeba polyphaga. Extracellular multiplication was observed on buffered charcoal yeast extract agar but not on a variety of conventional laboratory media. A 16S rRNA gene analysis placed the bacterium within the genus Legionella. Serological studies indicate that it is distinct from previously described species of the genus. This report also describes methods that should prove useful for the isolation and characterization of additional Legionella-like bacteria from free-living amoebae. In addition, the characterization of bacterial pathogens of amoebae has significant implications for understanding the ecology and identification of other unrecognized bacterial pathogens.

Dynamic susceptibility contrast MRI of regional cerebral blood volume in Alzheimer's disease

OBJECTIVE

The purpose of this study was to investigate the potential effectiveness of dynamic susceptibility contrast magnetic resonance imaging (MRI) to discriminate elderly patients with Alzheimer's disease from normal matched comparison subjects.

METHOD

Images of regional cerebral blood volume (CBV) were generated from echo-planar MRI with the dynamic susceptibility contrast method in 13 Alzheimer's disease patients and 13 comparison subjects group-matched on age and gender.

RESULTS

Temporoparietal cerebral blood volume, expressed as a percentage of the cerebellum value, was reduced 17% bilaterally in the patients with Alzheimer's disease. Blood volume in sensorimotor regions was reduced only 8.5% in the patients. Discriminant function analysis based on left and right temporoparietal measures correctly classified 88.5% of the subjects as patients or comparison subjects. Temporoparietal CBV was reduced even in mildly affected Alzheimer's disease patients (Mini-Mental State scores > 24).

CONCLUSIONS

Dynamic susceptibility contrast MRI of regional CBV is promising as a nonradioactive, potentially lower-cost alternative to other functional neuroimaging methods for evaluating Alzheimer's disease.

Severe cardiovascular disease and Alzheimer's disease: senile plaque formation in cortical areas

The main objectives of this study were to analyze the distribution of senile plaques (SP) and neurofibrillary tangles (NFT) in different cortical areas of patients suffering from severe cardiovascular diseases (CVD) and to compare them with Alzheimer's disease (AD) cases. Forty brains were divided into three groups: an AD group (n = 12), a CVD group (n = 17), and a nonheart disease control group (n = 11). The cortical areas examined were the middle frontal gyrus, the superior and inferior watershed areas, the hippocampal formation with the transentorhinal cortex, and the primary visual cortex. SP and NFT were counted in Bielschowsky-stained sections from all cortical areas and from the hippocampal formation and the transentorhinal cortex, respectively. Patients with severe CVD occupied an intermediate position in the spectrum of SP formation between AD and nonheart disease patients. The CVD group showed a higher prevalence of SP than the control group, and SP counts were significantly larger in the inferior watershed area, dentate gyrus, subiculum, and transentorhinal cortex. The distribution of SP was similar in CVD and AD patients. Control and CVD patients showed no difference regarding the number of NFT. The existence of a possible cardiovascular component in the genesis of SP is discussed.

Deficits in short-term memory in adult survivors of childhood abuse

Exposure to stress has been associated with alterations in memory function, and we have previously shown deficits in short-term verbal memory in patients with a history of exposure to the stress of combat and the diagnosis of posttraumatic stress disorder (PTSD). Few studies of any kind have focused on adult survivors of childhood physical and sexual abuse. The purpose of this study was to investigate short-term memory function in adult survivors of childhood abuse. Adult survivors of severe childhood physical and sexual abuse (n = 21), as defined by specific criteria derived from the Early Trauma Inventory (ETI), who were presenting for psychiatric treatment were compared with healthy subjects (n = 20) matched for several variables including age, alcohol abuse, and years of education. All subjects were assessed with the Wechsler Memory Scale (WMS) Logical (verbal memory) and Figural (visual memory) components, the Verbal and Visual Selective Reminding Tests (SRT), and the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Adult survivors of childhood abuse had significantly lower scores on the WMS Logical component for immediate and delayed recall in comparison to normal subjects, with no difference in visual memory, as measured by the WMS or the SRT, or IQ, as measured by the WAIS-R. Deficits in verbal memory, as measured by the WMS, were associated with the severity of abuse, as measured by a composite score on the ETI. Our findings suggest that childhood physical and sexual abuse is associated with long-term deficits in verbal short-term memory. These findings of specific deficits in verbal (and not visual) memory, with no change in IQ, are similar to the pattern of deficits that we have previously found in patients with combat-related PTSD.

Effect of denervation of the rat superior mesenteric arterial bed on the distribution of resistance among the first four orders of branching

The rat superior mesenteric artery with its first four orders of branching has been examined as an isolated perfused preparation. Lumen diameter and proportional resistance at each level have been determined and compared under conditions of constant pressure following methoxamine-induced constriction and acetylcholine-induced relaxation in intact and denervated preparations. A comparison was also made between intact preparations under conditions of constant pressure and constant flow. Lumen diameter and segment length were measured by analysis of video-taped images. The distribution of resistance among the first four orders of branching was estimated from the measured values using the Poiseuille formula. Intact first and fourth order branches had a proportionately low resistance, with the remaining resistance being fairly evenly distributed between the second and third order branches. No change in the pattern occurred as a result of either methoxamine or acetylcholine treatment. The pattern of distribution of resistance changed following denervation, so that proportional resistance was high in the first order branches and fell off from the second to fourth order branches. With methoxamine, the first order branches of denervates had a significantly higher resistance than in intact tissues, with the distribution of resistance in the second to fourth order branches following the basal resistance pattern. Reduction in the proportion of resistance with acetylcholine was similar in both intact and denervated preparations. Distribution of resistance did not differ between constant flow and constant pressure intact preparations.

MRI-based measurement of hippocampal volume in patients with combat-related posttraumatic stress disorder

OBJECTIVE

Studies in nonhuman primates suggest that high levels of cortisol associated with stress have neurotoxic effects on the hippocampus, a brain structure involved in memory. The authors previously showed that patients with combat-related posttraumatic stress disorder (PTSD) had deficits in short-term memory. The purpose of this study was to compare the hippocampal volume of patients with PTSD to that of subjects without psychiatric disorder.

METHOD

Magnetic resonance imaging was used to measure the volume of the hippocampus in 26 Vietnam combat veterans with PTSD and 22 comparison subjects selected to be similar to the patients in age, sex, race, years of education, socioeconomic status, body size, and years of alcohol abuse.

RESULTS

The PTSD patients had a statistically significant 8% smaller right hippocampal volume relative to that of the comparison subjects, but there was no difference in the volume of other brain regions (caudate and temporal lobe). Deficits in short-term verbal memory as measured with the Wechsler Memory Scale were associated with smaller right hippocampal volume in the PTSD patients only.

CONCLUSIONS

These findings are consistent with a smaller right hippocampal volume in PTSD that is associated with functional deficits in verbal memory.

A case-based anatomy course

A course is described in which the students give consideration to clinical cases as they review their current knowledge, and follow a set protocol which guided them in preparing their learning. The students are required to examine a case history, put down as key words either their first answer or the knowledge they consider they would need to answer specific questions. They then select stations at which additional information, wet specimens, models and radiological images assist them in upgrading their knowledge. They complete the exercise by writing a final answer to the questions on the case. The tutor is able through examination of the key words to determine the knowledge of the students as they enter, and confirm appropriate learning by inspection of the final answer. The students are able to identify their own deficiencies, develop strategies for thinking and learning, resulting in the acquisition of expertise in problem solving, and extend their communication skills by working with colleagues. While the course was designed for second-year anatomy teaching it could be applied to other disciplines.

Deficits in short-term memory in posttraumatic stress disorder

OBJECTIVE

The purpose of this study was to compare the memory function of patients with posttraumatic stress disorder (PTSD) to that of matched comparison subjects.

METHOD

Vietnam veterans with combat-related PTSD (N = 26) were compared to physically healthy comparison subjects (N = 15) matched for age, race, sex, years of education, handedness, socioeconomic status, and alcohol abuse. Memory and intelligence were assessed with a battery of neuropsychological tests, including the Russell revision of the Wechsler Memory Scale, the Selective Reminding Test, and subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R).

RESULTS

The PTSD patients scored significantly lower than the comparison subjects on the Wechsler Memory Scale logical memory measures for immediate recall (mean = 11.6, SD = 3.3 versus mean = 20.9, SD = 6.6) and delayed recall (mean = 8.0, SD = 3.3 versus mean = 17.8, SD = 6.4). The PTSD patients also scored significantly lower on the total recall, long-term storage, long-term retrieval, and delayed recall measures for the verbal component of the Selective Reminding Test and on the recall, long-term storage, long-term retrieval, and continuous long-term retrieval measures for the visual component of the Selective Reminding Test. There was no significant difference between the PTSD patients and comparison subjects in prorated full-scale IQ as measured by the WAIS-R.

CONCLUSIONS

Patients with PTSD may have deficits in short-term memory. Counseling and rehabilitation that address these deficits may be of value for PTSD patients.

How we teach anatomy efficiently and effectively

An anatomy course is presented which stresses the teaching of applied anatomy using lectures, laboratory workshops and problem-solving tutorials. Laboratory workshops include the use of prosected specimens and body imaging such as CT scan and ultrasound, but do not include dissection. The problem-solving tutorials make extensive use of clinical cases and the application of anatomical knowledge. The course is taught by anatomists and practising physicians, and needs only 98 hours of curriculum time. The performance of the students and the positive attitudes of both students and faculty are enhanced by the design of the course.

Perivascular innervation is lost in experimental atherosclerosis

Nerve fibers, immunohistochemically positive for neuropeptide Y, tyrosine hydroxylase, calcitonin gene-related peptide and substance P, form a perivascular network surrounding the carotid arteries of New Zealand White rabbits. Transmission electron microscopy demonstrates that the nerve fibers are primarily located at the adventitial-medial border. Placing a silastic collar around a carotid artery for 14 days, in rabbits fed a diet high in cholesterol, resulted in a focal, intimal thickening in 10 out of 12 rabbits. Contralateral sham-operated arteries showed no intimal thickening. At sites where intimal thickening occurred, there was a disappearance of the perivascular nerve network. The carotid arteries from rabbits that did not respond to the collar and the sham-operated carotid arteries showed an intact and normal perivascular nerve network. In the group of animals which responded to the collar with intimal thickening, there was evidence of a proliferative response proximal to the collar and in this same tissue there was evidence of degeneration of nerve fibers. In conclusion, it has been demonstrated for the first time that, in regions of the carotid artery where intimal thickening occurred, there was an associated degeneration of the perivascular nerve network. The cause of this degeneration and its functional consequences require further investigation.

Quantitative magnetic resonance imaging in temporal lobe epilepsy: relationship to neuropathology and neuropsychological function

Magnetic resonance images (MRIs) were obtained from 25 patients with medically refractory epilepsy of temporal lobe origin (12 on the left, 13 on the right) and 14 right-handed control subjects. The hippocampi and temporal lobes were traced by computer on successive coronal images and the resulting measurements of area were summed for each region. The left and right hippocampi were symmetrical in the control subjects; however, for patients the hippocampus was smaller on the side of the seizure focus. Moreover, the left-right hippocampal ratio significantly differentiated the control subjects from each patient group. The left temporal lobe was significantly smaller than the right in control subjects. The epileptics' temporal lobes were smaller on the side of the seizure focus, compared to the temporal lobes in the control subjects. MRI hippocampal measurements were compared to hippocampal neuronal densities obtained postoperatively. Significant correlations were obtained between the ratio (side ipsilateral to focus/side contralateral to focus) of MRI hippocampal measurements and neuronal densities in all hippocampal subfields except CA2. Prior to surgery, patients were administered the Wechsler Memory Scale and the verbal Selective Reminding Test. Significant correlations existed between MRI measurements of the left hippocampus and the Wechsler logical memory percent retention scores and between the left temporal lobe measurements and the verbal Selective Reminding Test scores for patients with seizure foci in the left temporal lobe.

Capsaicin-sensitive nerves influence the release of atrial natriuretic factor by atrial stretch in the rat

Although many factors may modulate the release of atrial natriuretic factor (ANF), the primary mechanism has been demonstrated to be atrial stretch. Recent studies have led to the suggestion that the peptidergic innervation of the heart, through the release of peptides, may be involved in the control of ANF secretion. We have examined the influence of chronic capsaicin treatment on three models of atrial stretch that release ANF. This treatment inhibited ANF released through in vivo blood volume expansion and through balloon inflation in the right atrium of in vitro isolated perfused hearts. Immunohistochemical and electron microscopical analysis confirmed the absence of innervation of the heart by calcitonin gene related peptide and substance P immunoreactive nerve fibres and apparent lack of effect on atrial granules in capsaicin treated rats. We conclude that capsaicin-sensitive cardiac innervation is a component modulating the release of ANF, stimulated by atrial stretch in the rat.

Interrelationships of heterozygosity, growth rate and heterozygote deficiencies in the coot clam, Mulinia lateralis

Allozyme surveys of marine invertebrates commonly report heterozygote deficiencies, a correlation between multiple locus heterozygosity and size, or both. Hypotheses advanced to account for these phenomena include inbreeding, null alleles, selection, spatial or temporal Wahlund effects, aneuploidy and molecular imprinting. Previous studies have been unable to clearly distinguish among these alternative hypotheses. This report analyzes a large data set (1906 individuals, 15 allozyme loci) from a single field collection of the coot clam Mulinia lateralis and demonstrates (1) significant heterozygote deficiencies at 13 of 15 loci, (2) a correlation between the magnitude of heterozygote deficiency at a locus and the effect of heterozygosity at that locus on shell length, and (3) a distribution of multilocus heterozygosity which deviates from that predicted by observed single-locus heterozygosities. A critical examination of the abovementioned hypotheses as sources of these findings rules out inbreeding, null alleles, aneuploidy, population mixing and imprinting as sole causes. The pooling of larval subpopulations subjected to varying degrees of selection, aneuploidy or imprinting could account for the patterns observed in this study.