Evaluation of 90-day repeated dose oral toxicity of an aloe vera inner leaf gel beverage

Despite its popularity along with many proposed therapeutic applications, the safety profile of Aloe vera gel beverages remains unsettled. The putative toxicology concern has focused on the hydroxyanthraquinone derivatives (HADs) found in the latex portion of the Aloe leaf. Despite harvesting and processing designed to eliminate or significantly reduce these compounds, certain HADs, such as aloin, may be present and have been associated with carcinogenicity in non-decolorized whole leaf extract containing approximately 6400 ppm aloin A and 71 ppm aloin-emodin. Sprague Dawley rats had free access to drinking water or a commercially and widely available Aloe vera gel beverage (Forever Living Products) prepared from the inner leaves of Aloe barbadensis Miller containing 3.43 ppm total aloin for 90 days. Under the conditions of the study and based on the toxicological endpoints evaluated, there were no adverse test substance-related findings, including altered thyroid hormones. No histologic differences or histopathological changes were detected in the multiple tissues and organs examined. The Ki-67 proliferation assay demonstrated no increased cell proliferation in the liver, lungs, kidneys, or urinary bladder, which might have been attributed to the dietary administration of the Aloe vera gel beverage via drinking water for 90 days. These data lend increasing confidence regarding the safety of appropriately processed Aloe vera gel beverages, such as the beverage tested in this study.

RUTIN, a widely consumed flavonoid, that commonly induces hormetic effects

Rutin is a flavonoid present in numerous fruits and vegetables and therefore widely consumed by humans. It is also a popular dietary supplement of 250-500 mg/day. There is considerable consumer interest in rutin due to numerous reports in the biomedical literature of its multi-system chemo-preventive properties. The present paper provides the first assessment of rutin-induced hormetic concentration/dose responses, their quantitative features and mechanistic basis, along with their biological, biomedical, clinical, and public health implications. The findings indicate that rutin-induced hormetic dose responses are widespread, being reported in numerous biological models and cell types for a wide range of endpoints. Of critical importance is that the optimal hormetic findings shown in in vitro systems are currently not achievable for human populations due to low gastrointestinal tract bioavailability. These findings have the potential to strengthen future experimental studies with rutin, particularly concerning study design parameters.

Gene specific effects on brain volume and cognition of TMEM106B in frontotemporal lobar degeneration

Background and Objectives

TMEM106B has been proposed as a modifier of disease risk in FTLD-TDP, particularly in GRN mutation carriers. Furthermore, TMEM106B has been investigated as a disease modifier in the context of healthy aging and across multiple neurodegenerative diseases. The objective of this study is to evaluate and compare the effect of TMEM106B on gray matter volume and cognition in each of the common genetic FTD groups and in sporadic FTD patients.

Methods

Participants were enrolled through the ARTFL/LEFFTDS Longitudinal Frontotemporal Lobar Degeneration (ALLFTD) study, which includes symptomatic and presymptomatic individuals with a pathogenic mutation in C9orf72, GRN, MAPT, VCP, TBK1, TARDBP, symptomatic non-mutation carriers, and non-carrier family controls. All participants were genotyped for the TMEM106B rs1990622 SNP. Cross-sectionally, linear mixed-effects models were fitted to assess an association between TMEM106B and genetic group interaction with each outcome measure (gray matter volume and UDS3-EF for cognition), adjusting for education, age, sex and CDR®+NACC-FTLD sum of boxes. Subsequently, associations between TMEM106B and each outcome measure were investigated within the genetic group. For longitudinal modeling, linear mixed-effects models with time by TMEM106B predictor interactions were fitted.

Results

The minor allele of TMEM106B rs1990622, linked to a decreased risk of FTD, associated with greater gray matter volume in GRN mutation carriers under the recessive dosage model. This was most pronounced in the thalamus in the left hemisphere, with a retained association when considering presymptomatic GRN mutation carriers only. The minor allele of TMEM106B rs1990622 also associated with greater cognitive scores among all C9orf72 mutation carriers and in presymptomatic C9orf72 mutation carriers, under the recessive dosage model.

Discussion

We identified associations of TMEM106B with gray matter volume and cognition in the presence of GRN and C9orf72 mutations. This further supports TMEM106B as modifier of TDP-43 pathology. The association of TMEM106B with outcomes of interest in presymptomatic GRN and C9orf72 mutation carriers could additionally reflect TMEM106B's impact on divergent pathophysiological changes before the appearance of clinical symptoms.

Reliability and Validity of Smartphone Cognitive Testing for Frontotemporal Lobar Degeneration

Importance

Frontotemporal lobar degeneration (FTLD) is relatively rare, behavioral and motor symptoms increase travel burden, and standard neuropsychological tests are not sensitive to early-stage disease. Remote smartphone-based cognitive assessments could mitigate these barriers to trial recruitment and success, but no such tools are validated for FTLD.

Objective

To evaluate the reliability and validity of smartphone-based cognitive measures for remote FTLD evaluations.

Design, Setting, and Participants

In this cohort study conducted from January 10, 2019, to July 31, 2023, controls and participants with FTLD performed smartphone application (app)-based executive functioning tasks and an associative memory task 3 times over 2 weeks. Observational research participants were enrolled through 18 centers of a North American FTLD research consortium (ALLFTD) and were asked to complete the tests remotely using their own smartphones. Of 1163 eligible individuals (enrolled in parent studies), 360 were enrolled in the present study; 364 refused and 439 were excluded. Participants were divided into discovery (n = 258) and validation (n = 102) cohorts. Among 329 participants with data available on disease stage, 195 were asymptomatic or had preclinical FTLD (59.3%), 66 had prodromal FTLD (20.1%), and 68 had symptomatic FTLD (20.7%) with a range of clinical syndromes.

Exposure

Participants completed standard in-clinic measures and remotely administered ALLFTD mobile app (app) smartphone tests.

Main Outcomes and Measures

Internal consistency, test-retest reliability, association of smartphone tests with criterion standard clinical measures, and diagnostic accuracy.

Results

In the 360 participants (mean [SD] age, 54.0 [15.4] years; 209 [58.1%] women), smartphone tests showed moderate-to-excellent reliability (intraclass correlation coefficients, 0.77-0.95). Validity was supported by association of smartphones tests with disease severity (r range, 0.38-0.59), criterion-standard neuropsychological tests (r range, 0.40-0.66), and brain volume (standardized β range, 0.34-0.50). Smartphone tests accurately differentiated individuals with dementia from controls (area under the curve [AUC], 0.93 [95% CI, 0.90-0.96]) and were more sensitive to early symptoms (AUC, 0.82 [95% CI, 0.76-0.88]) than the Montreal Cognitive Assessment (AUC, 0.68 [95% CI, 0.59-0.78]) (z of comparison, -2.49 [95% CI, -0.19 to -0.02]; P = .01). Reliability and validity findings were highly similar in the discovery and validation cohorts. Preclinical participants who carried pathogenic variants performed significantly worse than noncarrier family controls on 3 app tasks (eg, 2-back β = -0.49 [95% CI, -0.72 to -0.25]; P < .001) but not a composite of traditional neuropsychological measures (β = -0.14 [95% CI, -0.42 to 0.14]; P = .32).

Conclusions and Relevance

The findings of this cohort study suggest that smartphones could offer a feasible, reliable, valid, and scalable solution for remote evaluations of FTLD and may improve early detection. Smartphone assessments should be considered as a complementary approach to traditional in-person trial designs. Future research should validate these results in diverse populations and evaluate the utility of these tests for longitudinal monitoring.

Taurine induces hormesis in multiple biological models: May have transformative implications for overall societal health

This paper represents the first integrative assessment and documentation of taurine-induced hormetic effects in the biological and biomedical areas, their dose response features, mechanistic frameworks, and possible public health, therapeutic and commercial applications. Taurine-induced hormetic effects are documented in a wide range of experimental models, cell types and for numerous biological endpoints, with most of these experimental findings being reported within the past five years. It is suggested that the concept of hormesis may have a transformative effect on taurine research and its public health and therapeutic applications.

Flavonoids commonly induce hormetic responses

The present paper provides a new perspective of previously published findings by Siwak (Food Chem 141:1227-1241, 2013) which showed that 15 structurally diverse flavonoids reduced toxicity (i.e., enhanced cell viability) from hypochlorite using the MTT assay within a pre-conditioning experimental protocol, with each agent showing a similar biphasic concentration response relationship. We use this Commentary to point out that each of the concentration response relationships are consistent with the hormetic dose response. The paper of Siwak (Food Chem 141:1227-1241, 2013) is unique in that it provides a comparison of a relatively large number of agents using the identical experimental protocol.

Large-scale network analysis of the cerebrospinal fluid proteome identifies molecular signatures of frontotemporal lobar degeneration

The pathophysiological mechanisms driving disease progression of frontotemporal lobar degeneration (FTLD) and corresponding biomarkers are not fully understood. We leveraged aptamer-based proteomics (> 4,000 proteins) to identify dysregulated communities of co-expressed cerebrospinal fluid proteins in 116 adults carrying autosomal dominant FTLD mutations (C9orf72, GRN, MAPT) compared to 39 noncarrier controls. Network analysis identified 31 protein co-expression modules. Proteomic signatures of genetic FTLD clinical severity included increased abundance of RNA splicing (particularly in C9orf72 and GRN) and extracellular matrix (particularly in MAPT) modules, as well as decreased abundance of synaptic/neuronal and autophagy modules. The generalizability of genetic FTLD proteomic signatures was tested and confirmed in independent cohorts of 1) sporadic progressive supranuclear palsy-Richardson syndrome and 2) frontotemporal dementia spectrum syndromes. Network-based proteomics hold promise for identifying replicable molecular pathways in adults living with FTLD. 'Hub' proteins driving co-expression of affected modules warrant further attention as candidate biomarkers and therapeutic targets.

Lobar Microbleeds in the Posterior Cortical Atrophy Syndrome: A Comparison to Typical Alzheimer's Disease

PURPOSE OF THE STUDY

Posterior cortical atrophy is a clinico-radiographical syndrome that presents with higher-order visual dysfunction and is most commonly due to Alzheimer's disease. Understanding factors associated with atypical presentations of Alzheimer's disease, such as posterior cortical atrophy (PCA), holds promise to shape our understanding of AD pathophysiology. Thus, we aimed to compare MRI evidence of lobar microbleeds (LMBs) in posterior cortical atrophy (PCA) syndrome to typical AD (tAD) and to assess and compare MRI evidence of cerebral amyloid angiopathy (CAA) in each group.

FINDINGS

We retrospectively collected clinical and MRI data from participants with PCA (n = 26), identified from an institutional PCA registry, and participants with tAD (n = 46) identified from electronic health records from a single institution. LMBs were identified on susceptibility-weighted imaging (SWI); the Fazekas grade of white matter disease was assessed using FLAIR images, and Boston criteria version 2.0 for cerebral amyloid angiopathy were applied to all data. The proportion of participants with PCA and LMB (7.7%) was lower than for tAD (47.8%) (p = 0.005). The frequency of "probable" CAA was similar in both groups, while "possible" CAA was more frequent in tAD (30.4%) than PCA (0%) (p = 0.001). The Fazekas grades were not different between groups. Lobar microbleeds on SWI were not more common in PCA than in typical AD. Clinicopathological investigations are necessary to confirm these findings. The factors that contribute to the posterior cortical atrophy phenotype are unknown.

Hormesis determines lifespan

This paper addresses how long lifespan can be extended via multiple interventions, such as dietary supplements [e.g., curcumin, resveratrol, sulforaphane, complex phytochemical mixtures (e.g., Moringa, Rhodiola)], pharmaceutical agents (e.g., metformin), caloric restriction, intermittent fasting, exercise and other activities. This evaluation was framed within the context of hormesis, a biphasic dose response with specific quantitative features describing the limits of biological/phenotypic plasticity for integrative biological endpoints (e.g., cell proliferation, memory, fecundity, growth, tissue repair, stem cell population expansion/differentiation, longevity). Evaluation of several hundred lifespan extending agents using yeast, nematode (Caenorhabditis elegans), multiple insect and other invertebrate and vertebrate models (e.g., fish, rodents), revealed they responded in a manner [average (mean/median) and maximum lifespans] consistent with the quantitative features [i.e., 30-60% greater at maximum (Hormesis Rule)] of the hormetic dose response. These lifespan extension features were independent of biological model, inducing agent, endpoints measured and mechanism. These findings indicate that hormesis describes the capacity to extend life via numerous agents and activities and that the magnitude of lifespan extension is modest, in the percentage, not fold, range. These findings have important implications for human aging, genetic diseases/environmental stresses and lifespan extension, as well as public health practices and long-term societal resource planning.

Quercetin induces its chemoprotective effects via hormesis

Quercetin is a polyphenol present in numerous fruits and vegetables and therefore widely consumed by humans with average daily dietary intakes of 10-20 mg/day. It is also a popular dietary supplement of 250-1000 mg/day. However, despite the widespread consumer interest in quercetin, due to its possible chemopreventive properties, the extensively studied quercetin presents a highly diverse and complex array of biological effects. Consequently, the present paper provides the first assessment of quercetin-induced hormetic concentration/dose responses, their quantitative features and mechanistic foundations, and their biological, biomedical, clinical, and public health implications. The findings indicate that quercetin-induced hormetic dose responses are widespread, being independent of biological model, cell type, and endpoint. These findings have the potential to enlighten future experimental studies with quercetin especially with respect to study design parameters and may also affect the appraisal of possible public health benefits and risks associated with highly diverse consumer consumption practices.

Polyamines and hormesis: Making sense of a dose response dichotomy

The diverse biological effects of polyamines (putrescine, spermidine and spermine) were reviewed in the context of hormesis in an integrative manner for the first time. The findings illustrate that each of these polyamines commonly induces hormetic dose responses in a wide range of biological models and types of cells for multiple endpoints in numerous plant species and animal models. Plant research emphasized preconditioning experimental studies in which the respective polyamines conferred some protection against the damaging effects of a broad range of environmental stressors such as drought, salinity, cold/heat, heavy metals and UV-damage in an hormetic manner. Polyamine-based animal hormesis studies emphasized biomedical endpoints such as longevity and neuroprotection. These findings have important biological and biomedical implications and should guide experimental designs of low dose investigations.

Naringin commonly acts via hormesis

The present paper provides the first integrative assessment of the capacity of naringin and its metabolite, naringenin, to induce hormetic dose responses within a broad range of experimental biomedical models. The findings indicate that these agents commonly induced protective effects that are typically mediated via hormetic mechanisms leading to biphasic dose-response relationships. The maximum protective effects are generally modest, 30-60 % greater than control group values. The range of experimental findings with these agents has been reported for models with various neurodegenerative diseases, nucleus pulpous cells (NPCs) located within intravertebral discs, several types of stem cells (i.e., bone marrow, amniotic fluid, periodontal, endothelial) as well as cardiac cells. These agents also were effective within preconditioning protocols protecting against environmental toxins such as ultraviolet radiation (UV), cadmium, and paraquat. The mechanism(s) by which the hormetic responses mediates these biphasic dose responses is complex but commonly involves the activation of nuclear factor erythroid 2-related factor (Nrf2), an increasingly recognized regulator of cellular resistance to oxidants. Nrf2 appears to play a role in controlling the basal and induced expression of an array of antioxidant response element-dependent genes to regulate oxidant exposure's physiological and pathophysiological outcomes. Hence its importance in the assessment of toxicologic and adaptive potential is likely to be significant.

Hormesis, biological plasticity, and implications for clinical trial research

The present paper identifies a critical factor that leads to false negative results (i.e., failing to indicate efficacy when beneficial results did occur) in randomized human drug trials. The paper demonstrates that human performance can only be enhanced by a maximum of 30-60% as described by the hormetic dose response which defines the limits of biological plasticity. However, human epidemiological/clinical trials typically contain such extensive variability that often requires responses greater than 2-3 times control group responses to show statistical significance. Thus, many potentially beneficial agents may be missed because the clinical trial fails to recognize and take into consideration the limits of biological plasticity. The paper proposes that this hormesis-biological plasticity-clinical trial conundrum can be addressed successfully via the use of a weight-of-evidence methodology similar to that used by regulatory agencies such as EPA in environmental assessment of chemical toxicity.

Plasma inflammation for predicting phenotypic conversion and clinical progression of autosomal dominant frontotemporal lobar degeneration

BACKGROUND

Measuring systemic inflammatory markers may improve clinical prognosis and help identify targetable pathways for treatment in patients with autosomal dominant forms of frontotemporal lobar degeneration (FTLD).

METHODS

We measured plasma concentrations of IL-6, TNFα and YKL-40 in pathogenic variant carriers (MAPT, C9orf72, GRN) and non-carrier family members enrolled in the ARTFL-LEFFTDS Longitudinal Frontotemporal Lobar Degeneration consortium. We evaluated associations between baseline plasma inflammation and rate of clinical and neuroimaging changes (linear mixed effects models with standardised (z) outcomes). We compared inflammation between asymptomatic carriers who remained clinically normal ('asymptomatic non-converters') and those who became symptomatic ('asymptomatic converters') using area under the curve analyses. Discrimination accuracy was compared with that of plasma neurofilament light chain (NfL).

RESULTS

We studied 394 participants (non-carriers=143, C9orf72=117, GRN=62, MAPT=72). In MAPT, higher TNFα was associated with faster functional decline (B=0.12 (0.02, 0.22), p=0.02) and temporal lobe atrophy. In C9orf72, higher TNFα was associated with faster functional decline (B=0.09 (0.03, 0.16), p=0.006) and cognitive decline (B=-0.16 (-0.22, -0.10), p<0.001), while higher IL-6 was associated with faster functional decline (B=0.12 (0.03, 0.21), p=0.01). TNFα was higher in asymptomatic converters than non-converters (β=0.29 (0.09, 0.48), p=0.004) and improved discriminability compared with plasma NfL alone (ΔR2=0.16, p=0.007; NfL: OR=1.4 (1.03, 1.9), p=0.03; TNFα: OR=7.7 (1.7, 31.7), p=0.007).

CONCLUSIONS

Systemic proinflammatory protein measurement, particularly TNFα, may improve clinical prognosis in autosomal dominant FTLD pathogenic variant carriers who are not yet exhibiting severe impairment. Integrating TNFα with markers of neuronal dysfunction like NfL could optimise detection of impending symptom conversion in asymptomatic pathogenic variant carriers and may help personalise therapeutic approaches.

A boot camp translation of Alzheimer's disease in Hispanic/Latino communities

Introduction

Hispanics/Latinos (H/Ls) are significantly underrepresented in Alzheimer's disease (AD) research participant samples. This exclusion limits our interpretation of research findings and understanding of the causes of brain health disparities. The Engaging Communities of Hispanics/Latinos for Aging Research (ECHAR) Network was created to engage, educate, and motivate H/Ls for participation in brain aging research by addressing several barriers to inclusion, including health literacy and AD-related communication.

Methods

We used a novel community-engaged method-Boot Camp Translation (BCT)-to translate medical jargon into action-based, community-relevant messages. H/L community members (n = 39) were recruited from three cities to work with local research teams and co-develop culturally responsive AD-related messaging. BCT meetings leveraged various techniques to identify key messages, the target audience for the messages, and methods to disseminate these messages. Themes were constructed collaboratively between BCT facilitators and community members as the group iteratively refined the conceptual framework and language for the main messages, with the goal to make AD messaging accessible for H/L community members.

Results

H/L community members showed significant improvements in subjective understanding (Cohen's d = 0.75; P < 0.001) and objective knowledge of Alzheimer's disease (Cohen's d = 0.79; P < 0.001) at BCT completion. H/L community members identified key messages that converged for all three cities. These were related to reducing stigma, emphasizing brain health and risk mitigation, and acknowledging the impact of AD on multi-generational families/households. Participants also recommended sharing these messages with H/Ls across the lifespan using multi-media avenues.

Discussion

The collaborative efforts identified culturally responsive and community-relevant messaging that may help address health literacy barriers contributing to AD-related disparities in H/L communities.

HIGHLIGHTS

Hispanics/Latinos are underrepresented in Alzheimer's disease and related dementias (ADRD) research despite increased risk.Limited ADRD health literacy may act as a recruitment barrier.Boot Camp Translation (BCT) is a process that targets health communication.We carried out BCT in three cities to co-develop ADRD messaging.Results highlight regional similarities and differences in ADRD communication.

Feasibility and acceptability of remote smartphone cognitive testing in frontotemporal dementia research

Introduction

Remote smartphone assessments of cognition, speech/language, and motor functioning in frontotemporal dementia (FTD) could enable decentralized clinical trials and improve access to research. We studied the feasibility and acceptability of remote smartphone data collection in FTD research using the ALLFTD Mobile App (ALLFTD-mApp).

Methods

A diagnostically mixed sample of 214 participants with FTD or from familial FTD kindreds (asymptomatic: CDR®+NACC-FTLD = 0 [N = 101]; prodromal: 0.5 [N = 49]; symptomatic ≥1 [N = 51]; not measured [N = 13]) were asked to complete ALLFTD-mApp tests on their smartphone three times within 12 days. They completed smartphone familiarity and participation experience surveys.

Results

It was feasible for participants to complete the ALLFTD-mApp on their own smartphones. Participants reported high smartphone familiarity, completed ∼ 70% of tasks, and considered the time commitment acceptable (98% of respondents). Greater disease severity was associated with poorer performance across several tests.

Discussion

These findings suggest that the ALLFTD-mApp study protocol is feasible and acceptable for remote FTD research.

HIGHLIGHTS

The ALLFTD Mobile App is a smartphone-based platform for remote, self-administered data collection.The ALLFTD Mobile App consists of a comprehensive battery of surveys and tests of executive functioning, memory, speech and language, and motor abilities.Remote digital data collection using the ALLFTD Mobile App was feasible in a multicenter research consortium that studies FTD. Data was collected in healthy controls and participants with a range of diagnoses, particularly FTD spectrum disorders.Remote digital data collection was well accepted by participants with a variety of diagnoses.

The absence of genotoxicity of Aloe vera beverages: A review of the literature

Aloe has a long history of topical and systemic use with testimonials of countless health benefits and is one of the most popular botanical medicines in the world for the management of a wide variety both of benign and serious ailments including irritable bowel syndromes, osteoarthritis, Type II diabetes mellitus, and viral respiratory illness. The human consumption of Aloe vera extract in beverage form has substantially grown over the last several decades, in no small part, due to the increased consumer interest in alternative approaches to health benefits. The principal aim of the present paper is to characterize the research to date that has explored the genotoxic potential of Aloe vera inner leaf gel extract and decolorized whole leaf extract used in commercially available food-grade drinkable products which contain no more than 10 ppm aloin. Despite prevailing public health opinion, especially in Europe, the consensus of the reviewed studies retrieved from the peer-reviewed literature together with a mutagenic evaluation of an Aloe vera whole leaf decolorized spray-dried powder is that these products are not genotoxic.

Lithium and hormesis: Enhancement of adaptive responses and biological performance via hormetic mechanisms

Biomedical and consumer interest in the health-promoting properties of pure single entities of known or unknown chemical constituents and mixtures has never been greater. Since its "rediscovery" in the 1950s, lithium is an example of such a constituent that represents an array of scientific and public health challenges and medical potentials that may now be understood best when seen through the lens of the dose-response paradigm known as hormesis. The present paper represents the first review of the capacity of lithium to induce hormetic dose responses in a broad range of biological models, organ systems, and endpoints. Of significance is that the numerous hormetic findings occur with extensive concentration/dose response evaluations with the optimal dosing being similar across multiple organ systems. The particular focus of these hormetic dose-response findings was targeted to research with a broad spectrum of stem cell types and neuroprotective effects. These findings suggest that lithium may have critically valuable systemic effects with respect to those therapeutically treated with lithium as well as for exposures that may be achieved via dietary intervention.

Spared speech fluency is associated with increased functional connectivity in the speech production network in semantic variant primary progressive aphasia

Semantic variant primary progressive aphasia is a clinical syndrome characterized by marked semantic deficits, anterior temporal lobe atrophy and reduced connectivity within a distributed set of regions belonging to the functional network associated with semantic processing. However, to fully depict the clinical signature of semantic variant primary progressive aphasia, it is necessary to also characterize preserved neural networks and linguistic abilities, such as those subserving speech production. In this case-control observational study, we employed whole-brain seed-based connectivity on task-free MRI data of 32 semantic variant primary progressive aphasia patients and 46 healthy controls to investigate the functional connectivity of the speech production network and its relationship with the underlying grey matter. We investigated brain-behaviour correlations with speech fluency measures collected through clinical tests (verbal agility) and connected speech (speech rate and articulation rate). As a control network, we also investigated functional connectivity within the affected semantic network. Patients presented with increased connectivity in the speech production network between left inferior frontal and supramarginal regions, independent of underlying grey matter volume. In semantic variant primary progressive aphasia patients, preserved (verbal agility) and increased (articulation rate) speech fluency measures correlated with increased connectivity between inferior frontal and supramarginal regions. As expected, patients demonstrated decreased functional connectivity in the semantic network (dependent on the underlying grey matter atrophy) associated with average nouns' age of acquisition during connected speech. Collectively, these results provide a compelling model for studying compensation mechanisms in response to disease that might inform the design of future rehabilitation strategies in semantic variant primary progressive aphasia.

Boron enhances adaptive responses and biological performance via hormetic mechanisms

Boron is shown in the present review to induce hormetic dose responses in a broad range of biological models, organ systems and endpoints. Of particular importance is that numerous hormetic findings have been reported with whole animal studies, with extensive dose response evaluations with the optimal dosing being similar across multiple organ systems. These findings appear to be underappreciated and suggest that boron may have clinically significant systemic effects beyond that of its putative and more subtle essentiality functions. The re-exploration of boron's bioactivity as seen through hormetic mechanisms may also underscore the value of this approach to the assessment of micronutrient effects in human health and disease.

Significant shifts in preclinical and clinical neurotoxicology: a review and commentary

The ever-expanding prevalence of adverse neurotoxic reactions of the brain in response to therapeutic and recreational drugs, dietary supplements, environmental hazards, cosmetic ingredients, a spectrum of herbals, health status, and environmental stressors continues to prompt the development of novel cell-based assays to better determine neurotoxic hazard. Neurotoxicants may cause direct and epigenetic damage to the nervous tissue and alter the chemistry, structure, or normal activity of the nervous system. In severe neurotoxicity due to exposure to physical or psychosocial toxicants, neurons are disrupted or killed, and a consistent pattern of clinical neural dysfunction appears. In utero exposure to neurotoxicants can lead to altered development of the nervous system [developmental neurotoxicity (DNT)]. Patients with certain disorders and certain genomic makeup may be particularly susceptible to neurotoxicants. Traditional cytotoxicity measurements, like cell death, are easy to measure, but insufficient at identifying current routine biomarkers of toxicity including functional impairment in cell communication, which often occurs before or even in the absence of cell death. The present paper examines some of the limitations of existing neurotoxicology in light of the increasing need to develop tools to meet the challenges of achieving greater sensitivity in detection and developing and standardizing methods for exploring the toxicologic risk of such neurotoxic entities as engineered nanomaterials and even variables associated with poverty.

A review of horses sent to slaughter for human consumption: impact of horsemeat consumption, residual banned drugs, and public health risks

Nearly all of the American horses exported to Mexico and Canada are slaughtered for human consumption, and their meat is either exported around the world or consumed locally. Previous work showed that 18 Thoroughbred racehorses purchased by rescues that would have otherwise been sold for export for the sole purpose of slaughter to produce meat for human consumption were administered phenylbutazone. We report the number of American horses exported to Canada and Mexico from 2016 to 2021, the presence of contaminated horsemeat from Canadian slaughterhouses, and the human use and idiosyncratic effects of veterinary phenylbutazone and side effects of clenbuterol, 2 of the drugs that were found in contaminated Canadian horsemeat. The number of live American horses exported to Canada declined precipitously from 2016 to 2017, and a second decline occurred in 2020. All food-producing animals are under strict regulatory control to prevent animals administered banned drugs to enter the food chain. A major principle of this program is zero tolerance for banned drugs and testing for compliance. No regulatory process is in place to remove horses administered banned drugs such as phenylbutazone. The efficacy lasts for more than 24 hours as a result of the irreversible binding to cyclooxygenase, slow elimination, and long elimination half-life of its metabolite oxyphenbutazone. High or frequent doses of phenylbutazone result in disproportionately increased plasma concentrations, which result in the residual presence in tissues. It is this fact that underlies the ban of this drug in food-producing animals. No human clinical surveillance program is in place to monitor individuals on the possible short- and long-term consequences of banned drugs in contaminated horsemeat. If the United States is unable to put in place a regulatory program to remove horses administered banned drugs as exists for all food-producing animals, the exportation of American horses across both borders for the sole purpose of slaughter for human consumption must end.

POSITIVE EMOTIONAL CONNECTION AND CAREGIVER WELL-BEING IN BEHAVIORAL-VARIANT FRONTOTEMPORAL DEMENTIA

Behavioral-variant frontotemporal dementia (bvFTD) is characterized by impairment in socioemotional functioning. Spouses caring for individuals with bvFTD often experience profound health/well-being declines, compared to Alzheimer’s disease (AD) caregivers and non-caregiving older adults. We hypothesized that disrupted positive emotional connections between spousal caregivers and individuals with bvFTD contribute to caregivers’ lower emotional well-being. 23 bvFTD-caregiver, 23 AD-caregiver, and 17 control dyads had a 10-minute conflict conversation in the laboratory. Positive emotional connections were measured as the covariation of partners’ positive emotional behaviors during the conversation. Caregiver emotional well-being was assessed via questionnaire (SF-36). We found that bvFTD caregivers had lower emotional well-being than AD caregivers and controls (who did not differ from each other, t=.80, p=.43), c=-.70, p<.01. Importantly, this effect was fully mediated by bvFTD caregivers' lower positive emotional connections, c’=-.38, n.s. We speculate that lower positive emotional connections can cause social isolation and contribute to bvFTD caregivers’ health/well-being declines.

The absence of genotoxicity of a mixture of aloin A and B and a commercial aloe gel beverage

Aloe products are increasingly valued as ingredients in food supplements and as flavoring agents. The global Aloe vera market is varied, large, growing, and increasingly important in food, cosmetics, and medicines. Aloin, an anthraquinone glycoside, is one of the major components by weight of the anthraquinone derivatives of Aloe vera gel. Principal metabolites, aloe emodin and emodin, are a source of debate concerning toxic vs salutary effects, hence the accurate toxicological characterization of these compounds has become increasingly important. The purpose of this study was to determine the genotoxic profile of a stabilized Aloe vera juice product derived from the inner filet and marketed as a beverage currently sold in the European Union containing 8 to 10 ppm aloin and a mixture of purified aloin A and B. The present data confirm that a commercial stabilized Aloe vera gel intended for consumption as a juice beverage is not genotoxic. Furthermore, both aloin A and B were negative in the same assays and therefore are also not genotoxic. These results are consistent with the work of other groups and contrast with data obtained using products containing the Aloe vera latex hydroxyanthracene derivatives (HADs).

A commentary on drug safety and genomics: Promising new agents may require expansion of guidelines for subject screening in clinical trials

The fatty acid amide hydrolase (FAAH) inhibitors likely represent a novel therapeutic yet complex target with the potential to impact various disease processes that present significant unmet medical needs. Despite a history of significant adverse events and still ill-defined risks associated with FAAH inactivation, potential clinical results of FAAH inhibitors for the management of human diseases suggest strongly that the research not be abandoned. In the present commentary we argue that the way to move forward safely and effectively may lie in universal expansion of clinical trials guidelines and toxicology protocols to include targeted genomic screening of clinical trial subjects. Generalization to the safety testing of many new pharmaceutical agents may be the silver lining of an otherwise dark cloud.

Safety, Tolerability, and Pharmacokinetics of FAAH Inhibitor BIA 10-2474: A Double-Blind, Randomized, Placebo-Controlled Study in Healthy Volunteers

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of BIA 10‐2474, a fatty acid amide hydrolase (FAAH) inhibitor, after first administration to healthy male and female participants. Participants (n = 116) were recruited into this phase I, double‐blind, randomized, placebo‐controlled, single ascending dose and multiple ascending dose (10‐day) study. The primary outcome was the safety and tolerability of BIA 10‐2474. Secondary outcomes were pharmacokinetics of BIA 10‐2474 and pharmacodynamics, considering plasma concentrations of anandamide and three other fatty acid amides (FAAs) and leukocyte FAAH activity. Single oral doses of 0.25–100 mg and repeated oral doses of 2.5–50 mg were evaluated. BIA 10‐2474 was well tolerated up to 100 mg as a single dose and up to 20 mg once daily for 10 days. In the cohort receiving repeated administrations of 50 mg, there were central nervous system adverse events in five of six participants, one with fatal outcome, which led to early termination of the study. BIA 10‐2474 showed a linear relationship between dose and area under plasma concentration‐time curve (AUC) across the entire dose range and reached steady state within 5–6 days of administration, with an accumulation ratio, based on AUC_0–24h, of <2 on Day 10. BIA 10‐2474 was rapidly absorbed with a mean terminal elimination half‐life of 8–10 hours (Day 10). BIA 10‐2474 caused reversible, dose‐related increases in plasma FAAs. In conclusion, we propose that these data, as well as the additional data generated since the clinical trial was stopped, do not provide a complete mechanistic explanation for the tragic fatality.

Bruce Nathan Ames - Paradigm shifts inside the cancer research revolution

Dr. Bruce Ames turned 92 on December 16, 2020. He considers his most recent work linking adequate consumption of 30 known vitamins and minerals with successful aging to be his most important contribution. With the passage of time, it is not uncommon for the accomplishments of a well-known scientist to undergo a parsimonious reductionism in the public mind - Pasteur's vaccine, Mendel's peas, Pavlov's dogs, Ames' test. Those of us in the research generation subsequent to Dr. Ames' are undoubtedly affected by our own unconscious tendencies toward accepting the outstanding achievements of the past as commonplace. In doing so, seminal advances made by earlier investigators are often inadvertently subsumed into common knowledge. But having followed Ames' work since the mid-1970s, we are cognizant that the eponymous Ames Test is but a single chapter in a long and rich narrative. That narrative begins with Ames' classic studies on the histidine operon of Salmonella, for which he was elected to the National Academy of Sciences. A summary of the historical progression of the understanding of chemical carcinogenesis to which Ames and his colleagues contributed is provided. Any summary of a topic as expansive and complex as the ongoing unraveling of the mechanisms underlying chemical carcinogenesis will only touch upon some of the major conceptual advances to which Ames and his colleagues contributed. We hope that scientists of all ages familiar with Ames only through the eponymous Ames Test will further investigate the historical progression of the conceptualization of cancer caused by chemical exposure. As the field of chemical carcinogenesis gradually moves away from primary reliance on animal testing to alternative protocols under the rubric of New Approach Methodologies (NAM) an understanding of where we have been might help to guide where we should go.

Dietary γ-Glutamylcysteine: Its Impact on Glutathione Status and Potential Health Outcomes

Glutathione (GSH) is a tripeptide that is readily synthesized intracellularly in humans and other mammals. More than a century of research suggests that GSH has numerous biological functions, including protection from the potential adverse events associated with reactive oxygen species (ROS) and related redox reactions that may induce oxidative stress, and that may be linked to innate detoxification processes. Normal tissue and plasma levels of GSH decline through the aging process and decrease during various disease states. While the health value of dietary GSH remains controversial, there is evidence that some metabolic intermediates, such as γ-glutamylcysteine (GGC) may function to preserve adequate GSH levels when the synthetic pathways decline in activity, and the innate antioxidant system is challenged. It is also important to recognize that among the thousands of protein-coding human genes and their respective polymorphisms, at least two genes (Gclc and Gclm) are directly involved with GSH synthesis via glutamate-cysteine ligase. This commentary examines the classic biochemistry, toxicology, safety, and clinical value of GSH and its intermediates that may be modulated by dietary supplementation.

COVID-19 during Pregnancy and Postpartum

Coronavirus Disease 2019 (COVID-19) triggered by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection has been declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Oxidative stress and its related metabolic syndromes are potential risk factors in the susceptibility to, and severity of COVID-19. In concert with the earliest reports of COVID-19, obstetricians started to diagnose and treat SARS-CoV-2 infections during pregnancy ("COVID-19-Pregnancy"). High metabolic demand to sustain normal fetal development increases the burden of oxidative stress in pregnancy. Intracellular redox changes intertwined with acute phase responses at the maternal-fetal interface could amplify during pregnancy. Interestingly, mother-to-fetus transmission of SARS-CoV-2 has not been detected in most of the COVID-19-Pregnancy cases. This relative absence of vertical transmission may be related to the presence of lactoferrin in the placenta, amniotic fluid, and lacteal secretions. However, the cytokine-storm induced during COVID-19-Pregnancy may cause severe inflammatory damage to the fetus, and if uncontrolled, may later result in autism spectrum-like disorders and brain development abnormalities in neonates. Considering this serious health threat to child growth and development, the prevention of COVID-19 during pregnancy should be considered a high priority. This review summarizes the intricate virulence factors of COVID-19 and elucidate its pathobiological spectrum during pregnancy and postpartum periods with a focus on the putative and complex roles of endogenous and exogenous lactoferrin in conferring immunological advantage to the host.

COVID-19 during Pregnancy and Postpartum

As the COVID-19 pandemic intensified the global health crisis, the containment of SARS-CoV-2 infection in pregnancies, and the inherent risk of vertical transmission of virus from mother-to-fetus (or neonate) poses a major concern. Most COVID-19-Pregnancy patients showed mild to moderate COVID-19 pneumonia with no pregnancy loss and no congenital transmission of the virus; however, an increase in hypoxia-induced preterm deliveries was apparent. Also, the breastmilk of several mothers with COVID-19 tested negative for the virus. Taken together, the natural barrier function during pregnancy and postpartum seems to deter the SARS-CoV-2 transmission from mother-to-child. This clinical observation warrants to explore the maternal-fetal interface and identify the innate defense factors for prevention and control of COVID-19-Pregnancy. Lactoferrin (LF) is a potent antiviral iron-binding protein present in the maternal-fetal interface. In concert with immune co-factors, maternal-LF modulates chemokine release and lymphocyte migration and amplify host defense during pregnancy. LF levels during pregnancy may resolve hypertension via down-regulation of ACE2; consequently, may limit the membrane receptor access to SARS-CoV-2 for cellular entry. Furthermore, an LF-derived peptide (LRPVAA) has been shown to block ACE receptor activity in vitro. LF may also reduce viral docking and entry into host cells and limit the early phase of COVID-19 infection. An in-depth understanding of LF and other soluble mammalian milk-derived innate antiviral factors may provide insights to reduce co-morbidities and vertical transmission of SARS-CoV-2 infection and may lead to the development of effective nutraceutical supplements.

A "Verbal Thermometer" for Assessing Neurodegenerative Disease: Automated Measurement of Pronoun and Verb Ratio from Speech

Clinicians often use speech to characterize neurodegenerative disorders. Such characterizations require clinical judgment, which is subjective and can require extensive training. Quantitative Production Analysis (QPA) can be used to obtain objective quantifiable assessments of patient functioning. However, such human-based analyses of speech are costly and time consuming. Inexpensive off-the-shelf technologies such as speech recognition and part of speech taggers may avoid these problems. This study evaluates the ability of an automatic speech to text transcription system and a part of speech tagger to assist with measuring pronoun and verb ratios, measures based on QPA. Five participant groups provided spontaneous speech samples. One group consisted of healthy controls, while the remaining groups represented four subtypes of frontotemporal dementia. Findings indicated measurement of pronoun and verb ratio was robust despite errors introduced by automatic transcription and the tagger and despite these off-the-shelf products not having been trained on the language obtained from speech of the included population.

Recommendations to distinguish behavioural variant frontotemporal dementia from psychiatric disorders

The behavioural variant of frontotemporal dementia (bvFTD) is a frequent cause of early-onset dementia. The diagnosis of bvFTD remains challenging because of the limited accuracy of neuroimaging in the early disease stages and the absence of molecular biomarkers, and therefore relies predominantly on clinical assessment. BvFTD shows significant symptomatic overlap with non-degenerative primary psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, obsessive-compulsive disorder, autism spectrum disorders and even personality disorders. To date, ∼50% of patients with bvFTD receive a prior psychiatric diagnosis, and average diagnostic delay is up to 5-6 years from symptom onset. It is also not uncommon for patients with primary psychiatric disorders to be wrongly diagnosed with bvFTD. The Neuropsychiatric International Consortium for Frontotemporal Dementia was recently established to determine the current best clinical practice and set up an international collaboration to share a common dataset for future research. The goal of the present paper was to review the existing literature on the diagnosis of bvFTD and its differential diagnosis with primary psychiatric disorders to provide consensus recommendations on the clinical assessment. A systematic literature search with a narrative review was performed to determine all bvFTD-related diagnostic evidence for the following topics: bvFTD history taking, psychiatric assessment, clinical scales, physical and neurological examination, bedside cognitive tests, neuropsychological assessment, social cognition, structural neuroimaging, functional neuroimaging, CSF and genetic testing. For each topic, responsible team members proposed a set of minimal requirements, optimal clinical recommendations, and tools requiring further research or those that should be developed. Recommendations were listed if they reached a ≥ 85% expert consensus based on an online survey among all consortium participants. New recommendations include performing at least one formal social cognition test in the standard neuropsychological battery for bvFTD. We emphasize the importance of 3D-T1 brain MRI with a standardized review protocol including validated visual atrophy rating scales, and to consider volumetric analyses if available. We clarify the role of 18F-fluorodeoxyglucose PET for the exclusion of bvFTD when normal, whereas non-specific regional metabolism abnormalities should not be over-interpreted in the case of a psychiatric differential diagnosis. We highlight the potential role of serum or CSF neurofilament light chain to differentiate bvFTD from primary psychiatric disorders. Finally, based on the increasing literature and clinical experience, the consortium determined that screening for C9orf72 mutation should be performed in all possible/probable bvFTD cases or suspected cases with strong psychiatric features.

A review of nutrition and dietary interventions in oncology

The complex cellular mechanisms and inter-related pathways of cancer proliferation, evasion, and metastasis remain an emerging field of research. Over the last several decades, nutritional research has prominent role in identifying emerging adjuvant therapies in our fight against cancer. Nutritional and dietary interventions are being explored to improve the morbidity and mortality for cancer patients worldwide. In this review, we examine several dietary interventions and their proposed mechanisms against cancer as well as identifying limitations in the currently available literature. This review provides a comprehensive review of the cancer metabolism, dietary interventions used during cancer treatment, anti metabolic drugs, and their impact on nutritional deficiencies along with a critical review of the following diets: caloric restriction, intermittent fasting, ketogenic diet, Mediterranean diet, Japanese diet, and vegan diet.

Oral repeated-dose toxicity studies of BIA 10-2474 in CD-1 mice

We independently and retrospectively reviewed three studies that evaluated the toxicity of BIA 10-2474 (3-(1-(cyclohexyl(methyl)carbamoyl)-lH-imidazol-4-yl)pyridine 1-oxide), a novel fatty acid amide hydrolase (FAAH) inhibitor in male and female CD-1 mice based upon raw data obtained from Bial Portela & Companhia S.A. (São Mamede do Coronado, Portugal). These studies were carried out prior to the clinical trial with BIA 10-2474 and formed part of the regulatory submission. An initial oral dose range-finding study with BIA 10-2474 showed that doses from 600 mg/kg/day were poorly tolerated with a high mortality rate and signs of weakness, prostration, labored breathing, clear lacrimation, tachypnea/bradypnea and decreased activity. At lower doses (100 and 300 mg/kg/day) there were few signs but post-mortem analysis showed increased liver weight. In a 28-day study a third of the animals receiving 500 mg/kg/day died or required euthanasia, with similar signs to those seen in the dose-range finding study. At lower doses (i.e. 100 and 300 mg/kg/day) there were few clinical signs although there were dose-related decreases in erythrocyte count and hemoglobin. Histopathology was seen in the 300 and 500 mg/kg/day groups and included hepatocellular hypertrophy (with increased liver weight), nephropathy and enterocyte vacuolation. Finally, in the 13-week oral gavage study, BIA 10-2474 was administered to CD-1 mice of both sexes at dose levels of 25, 75 and 150 mg/kg/day. Under these conditions, there were almost no clinical signs apart from a tendency to increase body-weight. Cholesterol was increased at 75 and 150 mg/kg and remained high after recovery. Liver and spleen weights increased at 75 and 150 mg/kg/day. Histopathologically, there was a dose-dependent increase in sciatic nerve and myofiber degeneration, hepatocellular hypertrophy, nephropathy and inflammatory loci in the bladder. The nerve damage and nephropathy seen at 150 mg/kg/day persisted after a 4-week recovery period. Toxicokinetic analysis in the 4- and 13-week studies showed that exposure was broadly dose-proportional with no evidence of accumulation. On the basis of the changes seen during the 13-week study, the NOAEL was established at 75 mg/kg/day.

Aloe veraat the frontier of glycobiology and integrative medicine: Health implications of an ancient plant

Aloe vera plant extracts are ubiquitous in foods, cosmetics, and medicine. Like all plants, these extracts contain an array of potential bioactives or glycans, which may contribute to health when applied or consumed. In the Aloe vera plant, these bioactives are dominated by acemannan, a type of carbohydrate, and related complexes of saccharides, proteins, and lipids. Clinical data suggest aloe extracts may be beneficial in the management of cutaneous and some systemic conditions, such as some forms of immune dysfunction, atherogenesis, malignancy, and numerous cell functions. These extracts also contain an entourage of bioactive substances that may be allergenic and potentially toxic as well as salutary. These substances include aloin and a variety of anthracenes. The concentrations of potential allergens, aloin, and related compounds are markedly reduced through controlled decolorization processes that are utilized by leading Aloe products manufacturers. The entourage effects of contemporary Aloe vera when consumed or applied topically represent opportunities for clinical investigation which may be applied to commercial consumer products and therapeutic indications. Future research should fully explore the range of bioactive glycan components and their respective safety and efficacy. The history and ongoing popularity of Aloe vera products represent a pragmatic mandate for well-designed investigation into the diverse functional roles of glycans.

Associations Between Tau, β-Amyloid, and Cognition in Parkinson Disease

Importance

Multiple disease processes are associated with cognitive impairment in Parkinson disease (PD), including Lewy bodies, cerebrovascular disease, and Alzheimer disease. It remains unknown whether tau pathology relates to cognition in patients with PD without dementia.

Objective

To compare tau aggregation in patients with PD who are cognitively normal (PD-CN), patients with PD with mild cognitive impairment (PD-MCI), and healthy control participants, and evaluate the relationships between β-amyloid (Aβ), tau, and cognition in patients with PD who did not have dementia.

Design, Setting, and Participants

This cross-sectional study recruited 30 patients with Parkinson disease (15 with PD-CN and 15 with PD-MCI) from a tertiary care medical center and research institutions from July 2015 through October 2016. One patient with PD-MCI did not receive a magnetic resonance imaging scan and thus was excluded from all analyses; 29 patients with PD were included in the present study. Participants underwent tau positron emission tomographic (PET) scanning with fluorine 18-labeled AV-1451, Aβ PET scanning with carbon 11-labeled Pittsburgh compound B, magnetic resonance imaging, cognitive testing, and neurologic evaluation. Imaging measures were compared with 49 healthy control participants.

Main Outcomes and Measures

Outcomes were tau PET measurements of groups of patients with PD-CN and PD-MCI. We hypothesized that tau aggregation across groups would be related to age and Aβ status.

Results

Of the 78 participants, 47 (60%) were female, and the mean (SD) age was 71.1 (6.6) years. Six patients with PD (21%) were Aβ-positive, of whom 1 was mildly cognitively impaired; 23 were Aβ-negative (79%). (Of the 49 healthy controls, 25 were Aβ-negative and 24 Aβ-positive.) Voxelwise contrasts of whole-brain tau PET uptake between patients with PD-CN and patients with PD-MCI, and additionally between all patients with PD and Aβ-negative controls, did not reveal significant differences. Tau PET binding did not differ between patients with PD-MCI and PD-CN in brain regions reflecting Alzheimer disease Braak stages 1/2, 3/4, or 5/6, and did not differ from Aβ-negative healthy older adults. Mean (SD) tau PET binding was significantly elevated in Aβ-positive patients with PD relative to Aβ-negative patients with PD within brain regions reflecting Alzheimer disease Braak stage 3/4 (1.22 [0.07] vs 1.14 [0.07]; P = .03) and Braak stage 5/6 (1.20 [0.07] vs 1.11 [0.08]; P = .02).

Conclusions and Relevance

These findings suggest that patterns of cortical Aβ and tau do not differ in people with PD-CN, people with PD-MCI, and healthy older adults. Age, Aβ, and tau do not differentiate patients with PD-CN and PD-MCI. Tau deposition is related to Aβ status and age in both people with PD and healthy older adults. Cognitive deficits in people with PD without dementia do not appear to reflect measureable Alzheimer disease.

Expediting toxicity testing with increased precision, predictive power, and clinical utility

Federal Government management of health risks associated with the use of therapeutics and unintended environmental chemical exposures must be expedited to meet public health needs. Although US agencies initiated the Tox21 strategy over a decade ago to expedite toxicity testing and improve the reliability of risk assessments, recent status reports indicate that achieving its goals is still decades away. Emerging technologies create an opportunity to both expedite toxicity testing and improve its predictive power. The way forward may be an augmentation of the strategy aimed at enhancing the resolution and scope of Tox21 and exploring the adaptability of real-time chemical sensor, digital imaging, and other technologies to toxicity testing. Among the anticipated returns on the associated investment would likely be enhanced accuracy in prediction, reductions in the time needed to conduct hazard identifications and toxicity assessments, and an overall increase in the precision and reliability of the risk assessment process. This in turn expedites risk management decisions and reduces scientific uncertainty and the need to incorporate margins of safety that can add cost without necessarily returning improved health protection.

18 F-flortaucipir tau positron emission tomography distinguishes established progressive supranuclear palsy from controls and Parkinson disease: A multicenter study

OBJECTIVE

¹⁸ F-flortaucipir (formerly ¹⁸ F-AV1451 or ¹⁸ F-T807) binds to neurofibrillary tangles in Alzheimer disease, but tissue studies assessing binding to tau aggregates in progressive supranuclear palsy (PSP) have yielded mixed results. We compared in vivo ¹⁸ F-flortaucipir uptake in patients meeting clinical research criteria for PSP (n = 33) to normal controls (n = 46) and patients meeting criteria for Parkinson disease (PD; n = 26).

METHODS

Participants underwent magnetic resonance imaging and positron emission tomography for amyloid-β (¹¹ C-PiB or ¹⁸ F-florbetapir) and tau (¹⁸ F-flortaucipir). ¹⁸ F-flortaucipir standardized uptake value ratios were calculated (t = 80-100 minutes, cerebellum gray matter reference). Voxelwise and region-of-interest group comparisons were performed in template space, with receiver operating characteristic curve analyses to assess single-subject discrimination. Qualitative comparisons with postmortem tau are reported in 1 patient who died 9 months after ¹⁸ F-flortaucipir.

RESULTS

Clinical PSP patients showed bilaterally elevated ¹⁸ F-flortaucipir uptake in globus pallidus, putamen, subthalamic nucleus, midbrain, and dentate nucleus relative to controls and PD patients (voxelwise p < 0.05 family wise error corrected). Globus pallidus binding best distinguished PSP patients from controls and PD (area under the curve [AUC] = 0.872 vs controls, AUC = 0.893 vs PD). PSP clinical severity did not correlate with ¹⁸ F-flortaucipir in any region. A patient with clinical PSP and pathological diagnosis of corticobasal degeneration had severe tau pathology in PSP-related brain structures with good correspondence between in vivo ¹⁸ F-flortaucipir and postmortem tau neuropathology.

INTERPRETATION

¹⁸ F-flortaucipir uptake was elevated in PSP versus controls and PD patients in a pattern consistent with the expected distribution of tau pathology. Ann Neurol 2017;82:622-634.

Food additive safety

Food is a very common source of toxicant exposure to humans. An unknown number of naturally occurring contaminants find their way into food. The most ominous are products of mold growth called mycotoxins, which include the carcinogenic aflatoxins. On the other hand, more than 2500 chemical substances are added to foods to modify or impart flavor, color, stability, and texture, to fortify or enrich nutritive value, or to reduce cost. In addition, an estimated 12,000 substances are used in such a way that they may unintentionally enter the food supply. The term “food additive” is a regulatory term that encompasses any functional substance that is normally neither consumed as a food itself, but is intentionally added to food (usually in small quantities) to augment its processing or to improve aroma, color, consistency, taste, texture, or shelf life. Additives are not considered “nutritional” even if they possess nutritive value. The purpose of the present review is to give an overview of the approaches to, and procedures involved in ensuring the safety of the US food supply in the context of food additives, with particular reference to the existing and emerging scientific and regulatory landscape and consumer perceptions.

An integrated approach to the safety assessment of food additives in early life

During the development of international standards by the Codex Alimentarius Commission, infant foods and their constituent ingredients are subject to rigorous risk analysis and are strictly regulated by many authorities. Various jurisdictions have approved only a limited number of additives specifically with regard to infant foods to fulfill specific technical requirements of quality. As part of the approval process, a rigorous safety assessment is essential to confirm that the use of additives does not pose any health risk for the consumer. An acceptable daily intake (ADI) may be derived from the toxicological databases. However, the ADI may not be applicable to infants because of the possible developmental sensitivities and potentially high exposure scenarios, leading to possible lower margins of safety than would often be determined for adult populations. There is interest in defining better food safety assessment approaches for pre-weaned infants aged less than 12–16 weeks. To confirm safe use in infants, we reviewed the suitability of the existing safety databases of six additives with historical uses in infant nutrition products. To determine further toxicity testing strategies, it is necessary to understand whether the chemical used in the additives is identical to endogenous physiological metabolites and/or whether immature organs of infants are targets of toxicity. Combined with an in-depth review of the existing relevant toxicological and nutritional studies, this integrated approach will facilitate decision-making. We propose a decision tree as a tool within this approach to help guide appropriate data requirements and identify data gaps. In cases of reasonable uncertainty, studies of targeted juvenile should be considered to investigate the safe use levels in food products.

Palm oil and threats to a critically important food source

The oil palm, an ancient tropical tree species that originated in West Africa, has a history of centuries-long use both as a food and a medicine. Based on its higher saturated fatty acid composition, primarily palmitic acid, concerns have been flagged about its nutritional attributes. Elevation of low-density lipoprotein cholesterol effects of the associated palmitic acid is far less profound than animal sources of this fatty acid and is linked with multiple health benefits. Recently, the European Food Safety Authority raised issues about potential health risks of the chloropropanols, heat- or acid-induced food contaminants created during the refining of all edible oils, and some hydrolyzed proteins. Despite the fact that the levels of 3-monochloropropane1,2 diol and its glycidyl esters are generally <800 ppb and without demonstrated toxicological effects in humans, the chloropropanols in palm oil appear to be a lightning rod for global criticism. The toxicological data are reviewed and evaluated, and an approach for mitigation of the emerging challenge is suggested.

Bioavailability of micronutrients obtained from supplements and food

Nutritional status is an important determinant of quality of life, morbidity, and mortality. This review is a survey of one of the least appreciated and understood factors that contributes significantly to nutritional health: that of bioavailability. As the economic importance of nutritional supplements and foods carrying claims of health promotion continues to grow, physicians are increasingly accountable for critically evaluating the therapeutic and toxicologic impact of any recommended nutritional supplements and foods, and to do so, an understanding of bioavailability is essential. As we learn more about nutrition, and as it becomes increasingly clear that our fund of knowledge about nutrition is not what it should be, physicians, allied health practitioners, patients, and public health policy makers are obliged to better understand the basis for efficacy and of safety of nutritional supplements and foods. The concept of bioavailability is central to advancing our clinical acumen, particularly for the older adult population (>55 years of age), which according to the Centers for Disease Control and Prevention, typically take 16 scripted medications daily. In addition, over half of all adults consume one or more dietary supplements ( http://www.cdc.gov/nchs/data/databriefs/db61.pdf ). The World Health Organization data demonstrate that older adults form the single largest demographic group at disproportionate risk of inadequate diet and malnutrition ( http://www.who.int/ageing/publications/global_health.pdf ) followed by the pediatric population ( http://data.unicef.org/nutrition/malnutrition.html ). The challenge and the importance of understanding the determinants of bioavailability and the fundamentals of toxicology are demonstrated through the consideration of this construct in polyphenols. In support of this review, we scanned the literature using PubMed and Google Scholar. We selected peer-reviewed studies and review papers using the following search terms: bioavailability, nutritional supplements, food matrix, polyphenols, flavonoids, toxicology, microbiome, dietary intake, and metabolism.

Effects of acute levodopa challenge on resting cerebral blood flow in Parkinson's Disease patients assessed using pseudo-continuous arterial spin labeling

Introduction. Levodopa is the gold-standard for treatment of Parkinson’s disease (PD) related motor symptoms. In this study, we used pseudo-continuous arterial spin labeling (pCASL) to quantify changes in cerebral blood flow (CBF) after acute oral administration of levodopa in PD patients.

Materials and Methods. Thirteen patients (3 females, age 66.2 ± 8.7 years) with moderately advanced PD (Hoehn and Yahr stage >2 (median 2.5), disease duration >3 years) were scanned on a 3T Siemens MR scanner before and after oral levodopa administration. Statistical parametric mapping was used to detect drug-induced changes in CBF and its correlation to clinical severity scales. Images were normalized and flipped in order to examine effects on the more affected (left) and less affected (right) cerebral hemispheres across the cohort.

Results. Levodopa did not change global CBF but increased regional CBF in dorsal midbrain, precuneus/cuneus, more affected inferior frontal pars opercularis and triangularis, bilateral pre- and postcentral gyri, more affected inferior parietal areas, as well as less affected putamen/globus pallidus by 27–74% (p < 0.05, FWE corrected for multiple comparisons). CBF change was negatively correlated with improvement in bradykinesia UPDRS-III subscore in the more affected precentral gyrus, and total predrug UPDRS-III score in the mid-cingulate region. Drug-induced CBF change in a widespread network of regions including parietal and postcentral areas was also negatively correlated with the predrug rigidity UPDRS-III subscore.

Conclusion. These findings are in line with prior reports of abnormal activity in the nigrostriatal pathway of PD patients and demonstrate the feasibility of pCASL as a neuroimaging tool for investigating in vivo physiological effects of acute drug administration in PD.