The Mediating Role of Cortical Atrophy on the Relationship between the Resilience Index and Cognitive Function: Findings from the Healthy Brain Initiative

Background

Lifestyle factors are linked to differences in brain aging and risk for Alzheimer's disease, underscored by concepts like 'cognitive reserve' and 'brain maintenance'. The Resilience Index (RI), a composite of 6 factors (cognitive reserve, physical and cognitive activities, social engagement, diet, and mindfulness) provides such a holistic measure.

Objective

This study aims to examine the association of RI scores with cognitive function and assess the mediating role of cortical atrophy.

Methods

Baseline data from 113 participants (aged 45+, 68% female) from the Healthy Brain Initiative were included. Life course resilience was estimated with the RI, cognitive performance with Cognivue®, and brain health using a machine learning derived Cortical Atrophy Score (CAS). Mediation analysis probed the relationship between RI, cognitive outcomes, and cortical atrophy.

Results

In age and sex adjusted models, the RI was significantly associated with CAS (β= -0.25, p = 0.006) and Cognivue® scores (β= 0.32, p < 0.001). The RI-Cognivue® association was partially mediated by CAS (β= 0.07; 95% CI [0.02, 0.14]).

Conclusions

Findings revealed that the collective effect of early and late-life lifestyle resilience factors on cognition are partially explained by their association with less brain atrophy. These findings underscore the value of comprehensive lifestyle assessments in understanding the risk and progression of cognitive decline and Alzheimer's disease in an aging population.

Emerging drugs for dementia with Lewy Bodies: a review of Phase II & III trials

INTRODUCTION

Despite faster cognitive decline and greater negative impact on patients and family caregivers, drug development efforts in Dementia with Lewy Bodies (DLB) fall behind those for Alzheimer's Disease (AD). Current off-label drug DLB treatment options are limited to symptomatic agents developed to address cognitive deficits in AD, motor deficits in Parkinson's Disease, or behavioral symptoms in psychiatric disease. Aided by recent improvements in DLB diagnosis, a new focus on the development of disease-modifying agents (DMA) is emerging.

AREAS COVERED

Driven by evidence supporting different pathological mechanisms in DLB and PDD, this review assesses the evidence on symptomatic drug treatments and describes current efforts in DMA development in DLB. Specifically, our goals were to: (1) review evidence supporting the use of symptomatic drug treatments in DLB; (2) review the current DMA pipeline in DLB with a focus on Phase II and III clinical trials; and (3) identify potential issues with the development of DMA in DLB. Included in this review were completed and ongoing drug clinical trials in DLB registered on ClinicalTrials.gov (no time limits set for the search) or disseminated at the 2023 international conference on Clinical Trials in AD. Drug clinical trials registered in non-US clinical trial registries were not included.

EXPERT OPINION

Adoption of current symptomatic drug treatments used off-label in DLB relied on efficacy of benefits in other disorders rather than evidence from randomized controlled clinical trials. Symptoms remain difficult to manage. Several DMA drugs are currently being evaluated as either repurposing candidates or novel small molecules. Continued improvement in methodological aspects including development of DLB-specific outcome measures and biomarkers is needed to move the field of DMA drug development forward.

Neighborhood greenspace and neighborhood income associated with white matter grade worsening: Cardiovascular Health Study

INTRODUCTION

We examined whether a combined measure of neighborhood greenspace and neighborhood median income was associated with white matter hyperintensity (WMH) and ventricle size changes.

METHODS

The sample included 1260 cognitively normal ≥ 65-year-olds with two magnetic resonance images (MRI; ≈ 5 years apart). WMH and ventricular size were graded from 0 (least) to 9 (most) abnormal (worsening = increase of ≥1 grade from initial to follow-up MRI scans). The four-category neighborhood greenspace-income measure was based on median neighborhood greenspace and income values at initial MRI. Multivariable logistic regression tested associations between neighborhood greenspace-income and MRI measures (worsening vs. not).

RESULTS

White matter grade worsening was more likely for those in lower greenspace-lower income neighborhoods than higher greenspace-higher income neighborhoods (odds ratio = 1.73; 95% confidence interval = 1.19-2.51).

DISCUSSION

The combination of lower neighborhood income and lower greenspace may be a risk factor for worsening white matter grade on MRI. However, findings need to be replicated in more diverse cohorts.

HIGHLIGHTS

Population-based cohort of older adults (≥ 65 years) with greenspace and MRI dataCombined measure of neighborhood greenspace and neighborhood income at initial MRIMRI outcomes included white matter hyperintensities (WMH) and ventricular sizeLongitudinal change in MRI outcomes measured approximately 5 years apartWorsening WMH over time more likely for lower greenspace-lower income neighborhoods.

Mindfulness and Care Experience in Family Caregivers of Persons Living with Dementia

Background

Greater mindfulness, the practice of awareness and living in the moment without judgement, has been linked to positive caregiving outcomes in dementia caregivers and its impact attributed to greater decentering and emotion regulation abilities. Whether the impact of these mindfulness-based processes varies across caregiver subgroups is unclear.

Objective

Analyze cross-sectional associations between mindfulness and caregiver psychosocial outcomes, considering different caregiver and patient characteristics.

Methods

A total of 128 family caregivers of persons living with Alzheimer's disease and related disorders were assessed on several mindfulness measures (i.e., global; decentering, positive emotion regulation, negative emotion regulation) and provided self-reported appraisals of caregiving experience; care preparedness; confidence, burden, and depression/anxiety. Bivariate relationships between mindfulness and caregiver outcomes were assessed with Pearson's correlations and stratified by caregiver (women versus men; spouse versus adult child) and patient (mild cognitive impairment (MCI) versus Dementia; AD versus dementia with Lewy bodies; low versus high symptom severity) characteristics.

Results

Greater mindfulness was associated with positive outcomes and inversely associated with negative outcomes. Stratification identified specific patterns of associations across caregiver groups. Significant correlations were found between all mindfulness measures and caregiving outcomes in male and MCI caregivers while the individual mindfulness component of positive emotion regulation was significantly correlated to outcomes in most caregiver groups.

Conclusion

Our findings support a link between caregiver mindfulness and improved caregiving outcomes and suggest directions of inquiry into whether the effectiveness of dementia caregiver-support interventions may be improved by targeting specific mindfulness processes or offering a more inclusive all-scope approach depending on individual caregiver or patient characteristics.

MINDFULNESS AND CAREGIVING EXPERIENCE IN ADRD CAREGIVERS

Mindfulness (being present in the moment without judgement) has been linked to greater caregiver emotional health. Recent mindfulness-based interventions report improved coping skills, mood, and reduced stress in dementia caregivers. In this cross-sectional study of 141 ADRD caregivers, we assessed whether the relationship between caregiver mindfulness and caregiver experience varies by caregiver gender, relationship to patient (spouse-vs-child), etiology (AD-vs-LBD), or stage (MCI-vs-dementia). A stratified univariate analytic approach was used. Four mindfulness parameters (AMPS scale) were used: global score (GS), decentering (F1), positive (F2), and negative emotional regulation (F3). Outcomes included positive and negative appraisals of caregiving (PANAC), preparedness, care confidence, and depression. GS was linked to positive outcomes in male (rPANAC+=0.32/p=0.005), spouse caregivers (rPANAC+)=0.32/p=0.006 ) of ADRD patients regardless of etiology (rPANAC+=0.31/p=0.013 for AD; rconfidence=0.31/p=0.036 for LBD) and stage (rPANAC+=0.33/p=0.010 and rpreparedness=0.38,/p=0.008 for MCI; rPANAC+=0.29/p=0.011 and rconfidence=0.31/p=0.007 for dementia). Inverse relationships were observed with negative outcomes in male (rPANAC-=-0.46/p=0.002 and rdepression=-0.41/p=0.005), spouse caregivers (rPANAC-=-0.25/p=0.035 and rdepression=-0.30/p=0.009) of AD patients (rPANAC-=-0.25/p=0.043 and rdepression=-0.33/p=0.009) in early stages (rdepression=-0.41/p=0.001). F2 contributed to most relationships, with F3 and F1 significant in some but not all caregiver groups. Specifically, male spouse caregivers of AD patients regardless of stage may benefit from full-scope (F1-F3) programs while those of LBD patients from programs focused on improving emotional regulation (F2-F3). Wives of AD and LBD patients may in turn benefit from programs to improve positive emotional regulation (F2). Findings suggest that tailoring mindfulness-based interventions to specific caregiver groups may be effective in improving caregiver experience and mood.

THE RELATIONSHIP BETWEEN ADVANCE CARE PLANNING AND COGNITIVE FUNCTION IN A MULTICULTURAL COHORT

Engagement in Advance care planning (ACP) – the process of communicating preferences for future medical decisions, has been linked to increasing age, greater decision-making capacity, and higher education, and is more prevalent in White older adults. To advance knowledge of ACP in multicultural populations, we examined variations in the relationship between sociodemographics, cognitive functionality and ACP. A total of 303 older (mean-age: 69.4±10.5; 69.9% females; 29.6% Non-Hispanic White, 21.2% African American, and 49.2% Hispanic) participants in a community-based dementia screening program were included. ACP measures included life insurance, disability insurance, long-term care (LTC) insurance, power of attorney (POA), living will, and having a health care proxy (HCP). Although most participants had health insurance (92.4%, no differences by race), low rates of ACP engagement were found in racial/ethnic minorities across multiple ACP measures (all ≤40%). Black older adults had the highest use of life insurance (p&lt;.001). Higher ACP rates (i.e., LTC, HCP, living will) were associated with better global cognition (MoCA; p&lt; 0.05). Higher POA rates were associated with lower AD8 scores (30.1% in AD8&lt; 2 vs 15.4% in AD8≥2, p=0.003). Finally, ACP rates varied across racial-SES groups being highest in high SES White participants and lowest in minorities with low SES, regardless of subjective or objective cognitive performance. Findings link ACP to greater cognitive functionality and highlight racial and SES disparities in ACP engagement, particularly related to non-insurance-based planning. Understanding cultural differences in decision making can lead to targeted interventions to increase early ACP in cognitive aging and dementia for older adults.

Physical and sensory characterizations of oral coatings of oil/water emulsions

The physical and sensory properties of oil coatings on the tongue formed by five oil/water emulsions varying in oil content were investigated. A total of 20 subjects processed orally each emulsion for 30 s in triplicate. In vivo fluorescence measurements at the front and back of the anterior tongue were made to quantify the oil fraction deposited at different time points. Calibration lines relating fluorescence intensity to oil fraction were determined using pig tongues at 37.5 °C to mimic oral conditions. The oil fraction on the tongue increased linearly with an increasing oil content of the emulsions. The oil fraction deposited at the back of the anterior tongue was 1.5-2.0× larger than at the front. The intensity of sensory attributes describing after-feel perception was related to the oil fraction by Weber-Fechner's law. This study uses in vivo fluorescence to study food behavior in the mouth and unravel new insights in after-feel perception of emulsions.

A randomized, double-blind, placebo-controlled trial of polyethylene glycol effects on fasting and postprandial rectal sensitivity and symptoms in hypersensitive constipation-predominant irritable bowel syndrome

AIM

To assess the effect of polyethylene glycol 3350 (PEG) on fasting and postprandial (PP) perception of rectal distension and symptoms in hypersensitive constipation-predominant irritable bowel syndrome (IBS-C).

METHODS

Forty-two patients meeting Rome II criteria for IBS-C and with a pain threshold of < 32 mmHg were included in a randomized, double-blind, placebo-controlled trial. Patients received either oral PEG, 3.45 g t.i.d. orally for 30 days or placebo. Rectal sensitivity was assessed before and after treatment with a barostat using the ascending method of limits, during basal and PP periods.

RESULTS

No changes in fasting and PP rectal tone and thresholds for first sensation, gas sensation, urge to defecate, and pain was observed with PEG in relation to placebo. In both groups, pressure at which patients crossed the thresholds for noxious (PEG: from 28 ± 8.8 to 22 ± 6.9 mmHg) and non noxious (PEG: from 16 ± 4.9 to 12 ± 3.6 mmHg) stimuli decreased compared with pretreatment values. PEG improved consistency of faeces and showed a trend to diminish blood in faeces. PEG and placebo increased bowel movements per week (P < 0.001), and relieved symptoms without significant side-effects.

CONCLUSIONS

Both PEG 3350 and placebo were clinically useful in patients with IBS-C, an effect that cannot be explained by changes in rectal tone and sensation. The results support the concept that visceral sensitivity is not stable and has a heterogeneous response to drugs, and suggest the existence of a post healing hypersensitivity state.

Rectal sensation, pelvic floor function and symptom severity in Hispanic population with irritable bowel syndrome with constipation

OBJECTIVE

In patients with irritable bowel syndrome with constipation (IBS-C, Rome II) we determined if pelvic floor function correlates with rectal sensitivity and tone, and if the pelvic and rectal measurements correlate with symptoms.

PATIENTS AND METHODS

Sensory thresholds and tone in fasting and postprandial states were evaluated with an electronic barostat in 34 patients and 10 normal controls. The pelvic floor was assessed by defaecography.

RESULTS

Pain threshold to rectal distension was lower in IBS-C patients (P = 0.007). Postprandially, IBS-C patients showed lower values for sensation of gas, perception of urge, and pain threshold compared with controls. In IBS-C the anorectal angle widened less and showed less perineal mobility during defecation; the rectal tone in fasting IBS-C patients correlated with the angle at rest (P = 0.04) and with the perineal descent at rest (P = 0.01). The severity of abdominal discomfort or pain, and abdominal fullness correlated with the anorectal angle. The duration of symptoms and frequency of bowel movements correlated with perineal descent. Straining, mucus expulsion, and the feeling of incomplete evacuation correlated with rectal sensitivity variables.

CONCLUSION

Patients with IBS-C have lowered sensory thresholds for noxious and non-noxious stimuli, increased visceral sensitivity after food, less perineal mobility during defecation, and symptoms that correlate with rectal sensitivity and pelvic floor parameters.

A measure of the within-chromosome synergistic epistasis for Drosophila viability

In order to detect possible synergistic epistasis for viability in Drosophila melanogaster we assayed the relative viability of chromosomes II in: (i) panmixia, (ii) forced total homozygosity, and (iii) homozygosity for, on the average, half of their loci. As these genotypes were constructed using exactly the same set of chromosomes in the three cases, the design allows us to estimate the inbreeding depression rate at two different inbreeding levels in the absence of purging natural selection. Overall, no consistent synergistic epistasis was found. However, there was a small fraction of chromosomes whose severely deleterious effect when homozygous was almost significantly larger than expected from their viability when homozygous for half of their loci. This suggests occasional but important synergistic epistasis, which might confer evolutionary advantage to recombination in tightly linked genomes. Nevertheless, such epistasis is unlikely to be an evolutionary advantage driving the evolution of sexual anisogamous reproduction, as its contribution to overall viability is small when compared with the two-fold cost of anisogamy.

A selenopyrylium photosensitizer for photodynamic therapy related in structure to the antitumor agent AA1 with potent in vivo activity and no long-term skin photosensitization

Cationic chalcogenopyrylium dyes 5 were synthesized in six steps from p-aminophenylacetylene (9), have absorption maxima in methanol of 623, 654, and 680 nm for thio-, seleno-, and telluropyrylium dyes, respectively, and generate singlet oxygen with quantum yields [Phi((1)O(2))] of 0.013, 0.029, and 0.030, respectively. Selenopyrylium dye 5-Se was phototoxic to cultured murine Colo-26 and Molt-4 cells. Initial acute toxicity studies in vivo demonstrate that, at 29 mg (62 micromol)/kg, no toxicity was observed with 5-Se in animals followed for 90 days under normal vivarium conditions. In animals given 10 mg/kg of 5-Se via intravenous injection, 2-8 nmol of 5-Se/g of tumor was found at 3, 6, and 24 h postinjection. Animals bearing R3230AC rat mammary adenocarcinomas were treated with 10 mg/kg of 5-Se via tail-vein injection and with 720 J cm(-2) of 570-750-nm light from a filtered tungsten lamp at 200 mW cm(-2) (24 h postinjection of 5-Se). Treated animals gave a tumor-doubling time of 9 +/- 4 days, which is a 300% increase in tumor-doubling time relative to the 3 +/- 2 days for untreated dark controls. Mechanistically, the mitochondria appear to be a target. In cultured R3230AC rat mammary adenocarcinoma cells treated with 0.1 and 1.0 microM 5-Se and light, mitochondrial cytochrome c oxidase activity was inhibited relative to cytochrome c oxidase activity in untreated cells. Irradiation of isolated mitochondrial suspensions treated with 10 microM dye 5-Se inhibited cytochrome c oxidase activity. The degree of enzyme inhibition was abated in a reduced oxygen environment. Superoxide dismutase, at a final concentration of 30 U, did not alter the photosensitized inhibition of mitochondrial cytochrome c oxidase by dye 5-Se. The data suggest that singlet oxygen may play a major role in the photosensitized inhibition of mitochondrial cytochrome c oxidase.

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

Defaecography in patients with irritable bowel syndrome and healthy volunteers

BACKGROUND

In patients with IBS, many symptoms have their origin in the recto-anal segment, with motility changes in the rectum and in the internal anal sphincter, and alterations in rectal sensitivity. However, up to now, it is not known if these clinical and physiological changes are equated with morphological changes in the recto-anal segment.

METHODS

Sixteen consecutive patients with IBS (mean age 22, range 18-33 years; 13 females) and 10 healthy volunteers (mean age 34.5, range 19-50 yr.; 6 males) were evaluated prospectively with defaecography.

RESULTS

1) Anorectal angle: No significant differences were observed in the anorectal angle during rest (91.6 +/- 3.5 degrees vs 92.6 +/- 2.5 degrees) and during defaecation (92 +/- 5.5 degrees vs 98.7 +/- 2.6 degrees) between patients with IBS and healthy volunteers. However, patients with IBS were unable to widen the angle during defaecation, remaining the same at rest (91.6 +/- 3.5 degrees) as during defaecation (92 +/- 5.5 degrees). IBS patients with constipation (n = 2) compared to those with normal frequency defaecation (n = 13) showed no significant differences at rest (95 +/- 6 vs 89.8 +/- 4.1 degrees) and during defaecation (100 +/- vs 88.9 +/- 6.4 degrees). Healthy volunteers widened the angle by more than 5 degrees during defaecation. 2) Perineometry: although not significant, patients with IBS had less perineal descent during the simulated defaecation (1.98 +/- 0.37 cm) than healthy subjects (2.1 +/- 0.3 cm). Nevertheless, during squeeze there was significantly less mobility or perineal descent in patients with IBS than in control subjects (0.21 +/- 0.17 vs 0.95 +/- 0.21 cm; P = 0.01).

CONCLUSIONS

The findings of this study suggest that patients with IBS as a whole, whether constipation predominant or not, showed changes in pelvic-floor mobility.

Neuropathologic analysis of postmortal brain samples of HIV-seropositive and -seronegative i.v. drug addicts

Between 1987 and 1992 we performed forensic-pathologic and neuropathologic examinations on 70 cases of i.v. drug addicts who died of an overdose. In almost 25% of the cases HIV-positivity was revealed by serological examinations. In all the cases, irrespective of the result of the serological examination, a diffuse, reactive astrocytosis was the most prominent histologic alteration, accompanied by more or less pronounced regressive changes of this cell type in the deep layers of the white matter. Furthermore, also in all the cases, a slight to moderate, reactive proliferation of microglia could be assessed. In a few cases of the HIV-seropositive group a lymphocytic meningitis, viz. meningoencephalitis was found; these changes may indicate an early invasion of the central nervous system (CNS) by the HIV. In spite of these inflammatory alterations, in the latter cases no HIV-specific antigens (p24 and gp41) could be demonstrated in the brain, most probably because of the small number of infectious particles. In order to reveal the earliest phase of invasion of the CNS by the HIV, we performed a search for HIV-specific nucleic acid sequences by the aid of the polymerase chain reaction (PCR) in 8 HIV-seronegative and 8 normal control cases. Although, most probably due to contamination, also the control cases exhibited some PCR-signals, these were more pronounced and appeared with more primer-pairs within the group of HIV-seronegative drug addicts. It is conceivable that HIV penetrates the CNS and is harboured in it in latent form shortly after the primary infection.(ABSTRACT TRUNCATED AT 250 WORDS)