Semantic fluency: a sensitive marker for cognitive impairment in children with heavy diarrhea burdens?

APOE genotype, hippocampal volume, and cognitive reserve predict improvement by cognitive training in older adults without dementia: a randomized controlled trial

Cognitive training (CT) programs aim to improve cognitive performance and impede its decline. Thus, defining the characteristics of individuals who can benefit from these interventions is essential. Our objectives were to assess if the cognitive reserve (CR), APOE genotype (e4 carriers/non-carriers) and/or hippocampal volume might predict the effectiveness of a CT program. Participants were older adults without dementia (n = 226), randomized into parallel experimental and control groups. The assessment consisted of a neuropsychological protocol and additional data regarding total intracranial, gray matter, left/right hippocampus volume; APOE genotype; and Cognitive Reserve (CR). The intervention involved multifactorial CT (30 sessions, 90 min each), with an evaluation pre- and post-training (at six months); the control group simply following the center's routine activities. The primary outcome measures were the change in cognitive performance and the predictors of change. The results show that APOE-e4 non-carriers (79.1%) with a larger left hippocampal volume achieved better gains in semantic verbal fluency (R2 = .19). Subjects with a larger CR and a greater gray matter volume better improved their processing speed (R2 = .18). Age was correlated with the improvement in executive functions, such that older age predicts less improvement (R2 = .07). Subjects with a larger left hippocampal volume achieved more significant gains in general cognitive performance (R2 = .087). In conclusion, besides the program itself, the effectiveness of CT depends on age, biological factors like genotype and brain volume, and CR. Thus, to achieve better results through a CT, it is essential to consider the different characteristics of the participants, including genetic factors.Trial registration: Trial retrospectively registered on January 29th, 2020-(ClinicalTrials.gov -NCT04245579).

Myeloperoxidase as a biomarker for intestinal-brain axis dysfunction induced by malnutrition and Cryptosporidium infection in weanling mice

Cryptosporidiosis is a waterborne protozoal infection that may cause life-threatening diarrhea in undernourished children living in unsanitary environments. The aim of this study is to identify new biomarkers that may be related to gut-brain axis dysfunction in children suffering from the malnutrition/infection vicious cycle, necessary for better intervention strategies. Myeloperoxidase (MPO) is a well-known neutrophil-related tissue factor released during enteropathy that could drive gut-derived brain inflammation. We utilized a model of environmental enteropathy in C57BL/6 weanling mice challenged by Cryptosporidium and undernutrition. Mice were fed a 2%-Protein Diet (dPD) for eight days and orally infected with 107-C. parvum oocysts. C. parvum oocyst shedding was assessed from fecal and ileal-extracted genomic DNA by qRT-PCR. Ileal histopathology scores were assessed for intestinal inflammation. Prefrontal cortex samples were snap-frozen for MPO ELISA assay and NF-kb immunostaining. Blood samples were drawn by cardiac puncture after anesthesia and sera were obtained for serum amyloid A (SAA) and MPO analysis. Brain samples were also obtained for Iba-1 prefrontal cortex immunostaining. C. parvum-infected mice showed sustained stool oocyst shedding for six days post-infection and increased fecal MPO and inflammation scores. dPD and cryptosporidiosis led to impaired growth and weight gain. C. parvum-infected dPD mice showed increased serum MPO and serum amyloid A (SAA) levels, markers of systemic inflammation. dPD-infected mice showed greater MPO, NF-kB expression, and Iba-1 immunolabeling in the prefrontal cortex, an important brain region involved in executive function. Our findings suggest MPO as a potential biomarker for intestinal-brain axis dysfunction due to environmental enteropathy.

Differences between episodic and semantic memory in predicting observation-based activities of daily living in mild cognitive impairment and Alzheimer's disease

Individuals with mild cognitive impairment (MCI) can often progress into Alzheimer's Disease (AD). Research suggests that decline in episodic memory and semantic memory, as well as functional abilities, can be sensitive in predicting disease progression. This study aimed to (a) investigate episodic and semantic memory performance differences between AD and MCI, (b) determine if memory performance predicts observation-based activities of daily living (ADLs), and (c) explore whether semantic memory mediates the relationship between episodic memory and ADLs. Fifty-eight AD, 53 MCI, and 72 healthy control participants were administered the Rey-O, California Verbal Learning Test, Animal Fluency Test, Boston Naming Test, and Direct Assessment of Functional Status (DAFS). The results revealed, first, that AD participants performed significantly lower than the MCI participants across semantic memory and episodic memory tasks, with the exception of the Boston Naming Test. Second, hierarchical-stepwise regression analyses found that semantic memory significantly predicted DAFS orientation, communication, and financial skills in AD, but episodic memory predicted shopping skills. Furthermore, semantic memory significantly predicted DAFS transportation skills in AD and MCI. Third, within the overall sample, semantic memory mediated the relationship between episodic memory and ADLs. Taken together, the findings suggest decline in semantic memory (as measured by confrontational naming and category fluency) and episodic memory (as measured by list and complex visual design learning and recall) may lead to decline in different and specific aspects of functional abilities in AD and MCI.

The Implementation and Review of Cognitive Remediation Training for First Episode Psychosis in Singapore

Objective: Early intervention in patients with first episode psychosis (FEP) can improve cognitive abilities, with both short- and long-term benefits. In this paper, we describe the implementation and review of cognitive remediation training (CRT) in an Asian FEP population. The outcomes of the training are also evaluated and discussed. Methods: This naturalistic paper describes in detail the real-life implementation and conduct of CRT in an early psychosis intervention service. One hundred and nine patients with FEP underwent a 24-session CRT programme, using Cogpack and Neuropsychological Educational Approach to Remediation. The program is evaluated with pre- and post-CRT assessment scores which included Montreal Cognitive Assessment and Brief Assessment of Cognition in Schizophrenia. The rates of improvement on these cognitive assessments were evaluated using paired t-tests, with statistical significance set at p ≤ 0.05. Results: Of the 109 patients who underwent CRT, a total of 92 (84.4%) completed all 24 sessions. Paired t-tests between pre- and post-CRT assessments scores revealed that participants significantly improved on majority of the measures, including verbal memory, digit sequencing, and symbol coding. Conclusion: As with other cognitive remediation programmes, CRT has shown to improve cognitive functioning in patients with FEP. The results support the use of CRT in an Asian context and may serve as guidance for the implementation of similar training programmes in other Asian early psychosis intervention services.

The Burden of Enteropathy and "Subclinical" Infections

Environmental enteropathy is a chronic condition of the small intestine associated with increased intestinal permeability, mucosal inflammation, malabsorption, and systemic inflammation. It is commonly accompanied by enteric infections and is misleadingly considered a subclinical disease. Potential effects of enteric infections and enteropathy on vaccine responses, child growth, cognitive development, and even later life obesity, diabetes, and metabolic syndrome are increasingly being recognized. Herein, we review the evolving challenges to defining environmental enteropathy and enteric infections, current evidence for the magnitude and determinants of its burden, new assessment tools, and relevant interventions.

Improvement of long-term memory access with a pro-dopamine regulator in an elderly male: Are we targeting dopamine tone?

With aging, there is decline in both short-term and long-term memory. This effect is magnified by epigenetic insults on specific, dopamine- related genes (e.g., DRD2, DAT1) as well as by impaired or reduced mRNA transcription. In addition, long-term memory ability is positively correlated with dopamine function and there is evidence that aging is associated with a reduction in brain dopamine D2 receptors, with an acceleration seen in aging-induced dementia. As a result, the authors tested the acute effect of a Pro-Dopamine Regulator (KB220Z, liquid Nano variant) on an aspect of long-term memory performance in a 77-year-old, highly functional male, using the Animal Naming Test (ANT). An improvement in long-term memory retrieval had initially been noted during the subject’s follow-up neurology exam, after he had been, for other reasons, taking KB220z. The patient had been given a number of ANTs by his primary and, later, another neurologist, from 2013 to 2016. Because the number of ANT observations was small (N = 7 with two groups) and the data uncorrelated, a non-parametric Wilcoxon-Mann-Whitney test was performed to test mean differences. After KB220z, the patient had much higher scores (p = 0.04762) on the ANT vs. when not taking it. His scores increased from the 30^th percentile (pre-test) to the 76^th percentile, after the first administration of KB220z and, later, to the 98^th percentile, after a second administration of KB220z, six months later. The results indicate that KB220z, given acutely, increased a form of long-term memory retrieval in a highly functional, elderly male. Larger, double-blind, randomized controlled studies are encouraged.

Early-life enteric infections: relation between chronic systemic inflammation and poor cognition in children

The intestinal microbiota undergoes active remodeling in the first 6 to 18 months of life, during which time the characteristics of the adult microbiota are developed. This process is strongly influenced by the early diet and enteric pathogens. Enteric infections and malnutrition early in life may favor microbiota dysbiosis and small intestinal bacterial overgrowth, resulting in intestinal barrier dysfunction and translocation of intestinal bacterial products, ultimately leading to low-grade, chronic, subclinical systemic inflammation. The leaky gut-derived low-grade systemic inflammation may have profound consequences on the gut-liver-brain axis, compromising normal growth, metabolism, and cognitive development. This review examines recent data suggesting that early-life enteric infections that lead to intestinal barrier disruption may shift the intestinal microbiota toward chronic systemic inflammation and subsequent impaired cognitive development.

Diarrhea, stimulation and growth predict neurodevelopment in young North Indian children

BACKGROUND AND OBJECTIVE

Infants and young children in low to middle-income countries are at risk for adverse neurodevelopment due to multiple risk factors. In this study, we sought to identify stimulation and learning opportunities, growth, and burden of respiratory infections and diarrhea as predictors for neurodevelopment.

METHODS

We visited 422 North Indian children 6 to 30 months old weekly for six months. Childhood illnesses were assessed biweekly. At end study, we assessed neurodevelopment using the Ages and Stages Questionnaire 3rd ed. (ASQ-3) and gathered information on stimulation and learning opportunities. We identified predictors for ASQ-3 scores in multiple linear and logistic regression models.

RESULTS

We were able to explain 30.5% of the variation in the total ASQ-3 score by the identified predictors. When adjusting for child characteristics and annual family income, stimulation and learning opportunities explained most of the variation by 25.1%. Height for age (standardized beta: 0.12, p<.05) and weight for height z-scores (std. beta: 0.09, p<.05) were positively associated with the total ASQ-3 score, while number of days with diarrhea was negatively associated with these scores (std. beta: -0.13, p<0.01).

CONCLUSION

Our results support the importance of early child stimulation and general nutrition for child development. Our study also suggests that diarrhea is an additional risk factor for adverse neurodevelopment in vulnerable children.

Assessment of Cognitive Functions in Methadone Maintenance Patients

BACKGROUND

Methadone maintenance has received little scientific attention regarding neurocognitive effects. This study is aimed to assess the neuropsychological performance of methadone maintenance patients (MMP) compared to those healthy controls.

METHODS

Thirty-five MMP and 35 healthy controls, matched for age, gender, education and employment status, examined on a battery of tests aimed at assessing verbal fluency, executive functions, verbal memory, and working memory, using controlled oral word association test (COWAT), trial making test (TMT) Part A and B, Rey auditory verbal learning test (RAVLT), and backward digit span.

FINDINGS

MMP performed significantly poorly than controls in cognitive domains of verbal fluency, executive function, and verbal memory. MMP did not exhibit impairment in working memory, and TMT Part A compared to controls.

CONCLUSION

These results suggest that methadone consumption induces significant cognitive impairment that could compromise drug-treatment outcomes in MMP.

Cognitive decline and brain pathology in aging--need for a dimensional, lifespan and systems vulnerability view

Changes in brain structure and activity as well as cognitive function are commonly seen in aging. However, it is not known when aging of brain and cognition starts, and how much of the changes observed in seemingly healthy older adults that can be ascribed to incipient neurodegenerative disease. Recent research has yielded evidence that the borders between development and aging sometimes can be fuzzy, as can the borders between dementing disease and normal age changes. In this review, we argue that many factors affecting cognitive decline and dementia represents quantitative rather than qualitative differences in characteristics that commonly exist in the population. Further, factors known to affect brain and cognition in aging will often do so through a life-long accumulation of impact, and does not need to be specific to aging. And finally, a host of environmental and genetic factors and their interplay determine optimal aging, leaving room for potential for environmental interventions to affect the outcome of the aging process. Together, we argue that these factors call for a dimensional rather than categorical, lifespan rather than aging, and multidimensional systems-vulnerability rather than simple "hypothetical biomarker" model of age-associated cognitive decline and dementia. This has implications for how we should view lifespan trajectories of change in brain and cognitive function, and how we can study, prevent, diagnose and treat age-associated cognitive deficits.

Developing novel antisecretory drugs to treat infectious diarrhea

Diarrhea, a disease of poverty and poor sanitation, kills an estimated two million children each year. Oral rehydration therapy is a very simple and inexpensive treatment that has significantly reduced mortality from secretory diarrhea caused by rotavirus, cholera and enterotoxigenic Escherichia coli. The efficacy and adoption of oral rehydration therapy would be enhanced by a drug that reduces fluid loss associated with these diseases and alleviates disease symptoms. Secretion and absorption by the intestine offer a number of potential drug targets to reduce fluid loss. Among these, the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is the most attractive because it is the primary driver of secretion in cases of diarrhea caused by enterotoxigenic bacteria. CFTR can be inhibited by both natural products and synthetic small molecules. iOWH032 is a synthetic CFTR inhibitor that has recently entered clinical trials for this indication.

ApoE polymorphisms and diarrheal outcomes in Brazilian shanty town children

A series of studies have shown that the heavy burdens of diarrheal diseases in the first 2 formative years of life in children living in urban shanty towns have negative effects on physical and cognitive development lasting into later childhood. We have shown that APOE4 is relatively common in shanty town children living in Brazil (13.4%) and suggest that APOE4 has a protective role in cognitive development as well as weight-for-height in children with heavy burdens of diarrhea in early childhood (64/123; 52%), despite being a marker for cognitive decline with Alzheimer's and cardiovascular diseases later in life. APOE2 frequency was higher among children with heaviest diarrhea burdens during the first 2 years of life, as detected by PCR using the restriction fragment length polymorphism method, raising the possibility that ApoE-cholesterol balance might be critical for growth and cognitive development under the stress of heavy diarrhea burdens and when an enriched fat diet is insufficient. These findings provide a potential explanation for the survival advantage in evolution of genes, which might raise cholesterol levels during heavy stress of diarrhea burdens and malnutrition early in life.

Evolution in health and medicine Sackler colloquium: Evolution of the human lifespan and diseases of aging: roles of infection, inflammation, and nutrition

Humans have evolved much longer lifespans than the great apes, which rarely exceed 50 years. Since 1800, lifespans have doubled again, largely due to improvements in environment, food, and medicine that minimized mortality at earlier ages. Infections cause most mortality in wild chimpanzees and in traditional forager-farmers with limited access to modern medicine. Although we know little of the diseases of aging under premodern conditions, in captivity, chimpanzees present a lower incidence of cancer, ischemic heart disease, and neurodegeneration than current human populations. These major differences in pathology of aging are discussed in terms of genes that mediate infection, inflammation, and nutrition. Apolipoprotein E alleles are proposed as a prototype of pleiotropic genes, which influence immune responses, arterial and Alzheimer's disease, and brain development.