Clinical practice. Early Alzheimer's disease

The feasibility and practicality of auxiliary detection of spatial navigation impairment in patients with mild cognitive impairment due to Alzheimer's disease by using virtual reality

Background

Spatial disorientation in patients with mild cognitive impairment due to Alzheimer's disease (MCI due to AD) has become a subject of great interest. Medical practitioners are concerned about the serious issue of these patients who are getting lost. Therefore, the early detection of MCI due to AD is crucial.

New methods

We designed virtual reality (VR) protocols to test spatial recognition abilities. Our devices mainly included the Vive Pro Eye and the Steam VR program. We tested the three groups: young cognitively unimpaired (YCU), older cognitively unimpaired (OCU) and MCI due to AD. We also administered the Cognitive Abilities Screening Instrument and the Questionnaire on Everyday Navigational Ability for comparison.

Results

We adopted the testing results of 2 YCU, 3 OCU, and 4 MCI due to AD for analysis. Concerning cognitive abilities, YCU and OCU had better performance than MCI due to AD respectively. It was consistent with the recent memory and the total scores of the Cognitive Abilities Screening Instrument.

Comparison with existing methods

We introduced a real-life setting, the Tzu-Chiang campus at National Cheng Kung University, into the VR environment. It allowed us to assess daily road-recognizing abilities of participants in a controlled testing environment.

Conclusions

Several limitations were considered in this study, such as limited number of participants and low-quality images on the screen. Nonetheless, this device has the potential to serve as a screening tool for MCI due to AD based on its feasibility and practicality.

Salivary levels of disease-related biomarkers in the early stages of Parkinson's and Alzheimer's disease: A cross-sectional study

Introduction

Finding a non-invasive and repeatable tool has been recommended to make an accurate diagnosis of Alzheimer's disease (AD) and Parkinson's disease (PD).

Methods

70 volunteers participated in three groups: 24 with mild dementia of AD, 24 in the first and second stages of PD, and 22 healthy controls. After valuing the scores of cognitive tests, the salivary levels of phosphorylated tau (p-tau), total alpha-synuclein (α-syn), and beta-amyloid 1-42 (Aβ)‏‎ proteins have been evaluated. Finally, the cutoff points, receiver operating characteristic (ROC), sensitivity, and specificity have been calculated to find accurate and detectable biomarkers.

Results

Findings showed that the salivary level of Aβ was higher in both PD (p < 0.01) and AD (p < 0.001) patients than in controls. Moreover, the level of α-syn in both PD and AD patients was similarly lower than in controls (p < 0.05). However, the level of p-tau was only ‎higher in the AD group than in the control (p < 0.01). Salivary Aβ 1-42 level at a 60.3 pg/ml cutoff point revealed an excellent performance for diagnosing AD (AUC: 0.81).

Conclusion

Evaluation of p-tau, α-syn, and Aβ 1-42 levels in the saliva of AD and PD patients could help the early diagnosis. The p-tau level might be valuable for differentiation between AD and PD. Therefore, these hopeful investigations could be done to reduce the usage of invasive diagnostic methods, which alone is a success in alleviating the suffering of AD and PD patients. Moreover, introducing accurate salivary biomarkers according to the pathophysiology of AD and PD should be encouraged.

Automatic Analysis of MRI Images for Early Prediction of Alzheimer's Disease Stages Based on Hybrid Features of CNN and Handcrafted Features

Alzheimer's disease (AD) is considered one of the challenges facing health care in the modern century; until now, there has been no effective treatment to cure it, but there are drugs to slow its progression. Therefore, early detection of Alzheimer's is vital to take needful measures before it develops into brain damage which cannot be treated. Magnetic resonance imaging (MRI) techniques have contributed to the diagnosis and prediction of its progression. MRI images require highly experienced doctors and radiologists, and the analysis of MRI images takes time to analyze each slice. Thus, deep learning techniques play a vital role in analyzing a huge amount of MRI images with high accuracy to detect Alzheimer's and predict its progression. Because of the similarities in the characteristics of the early stages of Alzheimer's, this study aimed to extract the features in several methods and integrate the features extracted from more than one method into the same features matrix. This study contributed to the development of three methodologies, each with two systems, with all systems aimed at achieving satisfactory accuracy for the detection of AD and predicting the stages of its progression. The first methodology is by Feed Forward Neural Network (FFNN) with the features of GoogLeNet and DenseNet-121 models separately. The second methodology is by FFNN network with combined features between GoogLeNet and Dense-121 models before and after high-dimensionality reduction of features using the Principal Component Analysis (PCA) algorithm. The third methodology is by FFNN network with combined features between GoogLeNet and Dense-121 models separately and features extracted by Discrete Wavelet Transform (DWT), Local Binary Pattern (LBP) and Gray Level Co-occurrence Matrix (GLCM) methods called handcrafted features. All systems yielded super results in detecting AD and predicting the stages of its progression. With the combined features of the DenseNet-121 and handcrafted, the FFNN achieved an accuracy of 99.7%, sensitivity of 99.64%, AUC of 99.56%, precision of 99.63%, and a specificity of 99.67%.

Alzheimer's disease biomarkers in patients with obstructive sleep apnea hypopnea syndrome and effects of surgery: A prospective cohort study

Background

Obstructive sleep apnea hypopnea syndrome (OSAHS) may cause Alzheimer's disease (AD), t-tau, p-tau, Aβ42, and Aβ40 are important elements in the process of AD, and changes in the levels of these biomarkers may affect the cognitive functioning of patients. Our objective was to investigate whether uvulopalatopharyngoplasty could reduce the plasma levels of AD biomarkers in OSAHS patients and the potential correlations of AD biomarkers with cognitive impairment and sleepiness, and explore the independent influencing factors of cognitive function.

Methods

Alzheimer's disease biomarkers were measured in the plasma of 35 patients with severe OSAHS requiring surgical treatment and 16 healthy controls without OSAHS. The cognitive function and sleepiness of OSAHS patients was also evaluated. The case group was given uvulopalatopharyngoplasty and followed at the postoperative sixth month, the follow-up cases were 27, and plasma AD biomarker levels, cognitive function, and sleepiness were re-evaluated. The preoperative and postoperative AD biomarker levels OSAHS patients were compared with each other and those of the control group. Linear stepwise regression and lasso regression were used to explore the relationships of AD biomarkers with cognitive impairment and sleepiness.

Results

Significantly higher Aβ40, t-tau, p-tau in plasma were observed preoperatively in OSAHS patients comparing to controls (29.24 ± 32.52 vs. 13.18 ± 10.78, p = 0.049; 11.88 ± 7.05 vs. 7.64 ± 4.17, p = 0.037; 26.31 ± 14.41 vs. 17.34 ± 9.12, p = 0.027). The sixth month of postoperation, the plasma AD biomarkers (Aβ42, Aβ40, t-tau, p-tau) in plasma levels decreased significantly (0.23 ± 0.17 vs. 0.20 ± 0.16, p = 0.0001; 29.24 ± 32.52 vs. 23.52 ± 24.46, p = 0.0046; 11.88 ± 7.05 vs. 8.88 ± 6.21, p = 0.0001;26.31 ± 14.41 vs. 20.43 ± 10.50, p = 0.0001). A comparison of MMSE and ESS scores from before to after surgery revealed obvious differences (27.14 ± 1.65 vs. 29.07 ± 1.78, p = 0.0001; 11.91 ± 4.84 vs. 5.89 ± 2.83, p = 0.0001). Changes in cognitive function and sleepiness scores from before to after uvulopalatopharyngoplasty were significantly correlated with AD biomarkers. Body mass index and t-tau were potential influencing factors cognitive function.

Conclusion

Obstructive sleep apnea hypopnea syndrome can increase plasma AD biomarkers levels. Uvulopalatopharyngoplasty can improve patients' cognition and sleepiness, and the mechanism may be related to changes in plasma AD biomarkers. Higher AHI and higher t-tau level were identified as independent risk factors for cognitive decline.

An Efficient Lightweight Network Based on Magnetic Resonance Images for Predicting Alzheimer's Disease

Brain magnetic resonance images (MRI) are widely used for the classification of Alzheimer's disease (AD). The size of 3D images is, however, too large. Some of the sliced image features are lost, which results in conflicting network size and classification performance. This article uses key components in the transformer model to propose a new lightweight method, ensuring the lightness of the network and achieving highly accurate classification. First, the transformer model is imitated by using image patch input to enhance feature perception. Second, the Gaussian error linear unit (GELU), commonly used in transformer models, is used to enhance the generalization ability of the network. Finally, the network uses MRI slices as learning data. The depthwise separable convolution makes the network more lightweight. Experiments are carried out on the ADNI public database. The accuracy rate of AD vs. normal control (NC) experiments reaches 98.54%. The amount of network parameters is 1.3% of existing similar networks.

Measurement invariance testing of longitudinal neuropsychiatric test scores distinguishes pathological from normative cognitive decline and highlights its potential in early detection research

OBJECTIVE

Alzheimer's disease (AD) is a growing challenge worldwide, which is why the search for early-onset predictors must be focused as soon as possible. Longitudinal studies that investigate courses of neuropsychological and other variables screen for such predictors correlated to mild cognitive impairment (MCI). However, one often neglected issue in analyses of such studies is measurement invariance (MI), which is often assumed but not tested for. This study uses the absence of MI (non-MI) and latent factor scores instead of composite variables to assess properties of cognitive domains, compensation mechanisms, and their predictability to establish a method for a more comprehensive understanding of pathological cognitive decline.

METHODS

An exploratory factor analysis (EFA) and a set of increasingly restricted confirmatory factor analyses (CFAs) were conducted to find latent factors, compared them with the composite approach, and to test for longitudinal (partial-)MI in a neuropsychiatric test battery, consisting of 14 test variables. A total of 330 elderly (mean age: 73.78 ± 1.52 years at baseline) were analyzed two times (3 years apart).

RESULTS

EFA revealed a four-factor model representing declarative memory, attention, working memory, and visual-spatial processing. Based on CFA, an accurate model was estimated across both measurement timepoints. Partial non-MI was found for parameters such as loadings, test- and latent factor intercepts as well as latent factor variances. The latent factor approach was preferable to the composite approach.

CONCLUSION

The overall assessment of non-MI latent factors may pose a possible target for this field of research. Hence, the non-MI of variances indicated variables that are especially suited for the prediction of pathological cognitive decline, while non-MI of intercepts indicated general aging-related decline. As a result, the sole assessment of MI may help distinguish pathological from normative aging processes and additionally may reveal compensatory neuropsychological mechanisms.

Extra Virgin Olive Oil consumption from Mild Cognitive Impairment patients attenuates oxidative and nitrative stress reflecting on the reduction of the PARP levels and DNA damage

Oxidative/nitrative stress that results from the unbalance of the overproduction/clearance of reactive oxygen/nitrogen species (ROS/NOS), originated from a variety of endo- and/or exo-genous sources, can have detrimental effects on DNA and is involved in Alzheimer's disease (AD) pathology. An excellent marker of oxidative DNA lesions is 8-hydroxy-2'-deoxyguanosine (8-OHdG) while of nitrative stress the enzyme NOS2 (Nitric oxide synthase 2). Under massive oxidative stress, poly(ADP-ribose)polymerase 1 (PARP-1) enzyme activity, responsible for restoration of DNA damage, is augmented, DNA repair enzymes are recruited, and cell survival/or death is ensued through PARP-1 activation, which is correlated positively with neurodegenerative diseases. In this biochemical study the levels of PARP-1, 8-oxo-dG, and NOS2, Aβ1-42, and p-tau in their sera determined using Enzyme-Linked Immunosorbent Assay (ELISA). Patients diagnosed with Mild Cognitive Impairment participated in MICOIL clinical trial, were daily administered with 50 ml Extra Virgin Olive Oil (EVOO) for one year. All MCI patients' biomarkers that had consumed EVOO were tantamount to those of healthy participants, contrary to MCI patients who were not administered. EVOO administration in MCI patients resulted in the restoration of DNA damage and of the well-established "hallmarks" AD biomarkers, thanks probably to its antioxidant properties exhibiting a therapeutic potentiality against AD. Molecular docking simulations of the EVOO constituents on the crystal structure of PARP-1 and NOS-2 target enzymes were also employed, to study in silico the ability of the compounds to bind to these enzymes and explain the observed in vitro activity. In silico analysis has proved the binding of EVOO constituents on PARP-1and NOS-2 enzymes and their interaction with crucial amino acids of the active sites. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03362996. MICOIL GOV IDENTIFIER: NCT03362996.

Postchemotherapy hippocampal functional connectivity patterns in patients with breast cancer: a longitudinal resting state functional MR imaging study

The hippocampus plays a key role in cognitive function and emotion regulation due to its wide connection with the whole brain. This study examined the acute effect of chemotherapy on hippocampal and subfield functional connectivity and neuropsychological status in breast cancer patients (BC). This IRB approved study included 29 BC and 25 age matched healthy controls (HCs) who underwent resting state functional magnetic resonance imaging (Rs-fMRI), neuropsychological tests and blood examinations at baseline and one week after completing chemotherapy or in the same time interval. Within-group comparisons and group-by-time interactions analysis of hippocampus- and subregion- based functional connectivity were performed between the two groups. Functional connectivity changes were correlated with changes of blood examination and neuropsychological test scores in the BC group. The BC group had higher depression and anxiety scores, poorer performance on visual mobility, auditory memory and executive function than HCs (p < 0.05), and significantly abnormal estrodiol, total cholesterol and triglycerides (p < 0.05). BC survivors showed significant hippocampal functional connectivity changes mainly in the left insula, temporal lobe (Gaussian Random Field theory correction, P < 0.001) and the left inferior frontal gyrus (P < 0.01). The functional connections from the anterior hippocampus to the left temporal lobe were greater than the posterior hippocampus (P < 0.05). The hippocampus functional connectivity alterations were closely related to changes in depression scores, estrodiol and triglycerides (all p < 0.05). Chemotherapy induced especially anterior hippocampal functional connectivity abnormality, which is related to depression symptom, estrodiol and triglycerides disorders.

Effect of citrus peels-supplemented diet on longevity, memory index, redox status, cholinergic and monoaminergic enzymes in Drosophila melanogaster model

This study sought to determine the life span promoting effecof orange (Citrus sinensis), tangerine (Citrus maxima) and grapefruit (Citrus paradisi) peels in Drosophila melanogaster model. Flies (both gender, 3 to 5 days old) were divided into seven (7) groups (n = 5) containing 40 flies each; group I (control) flies were fed with basal diet, II-VII were flies were fed with basal diet containing 0.1 and 1.0% of tangerine peel (TP), orange peel (CP), and grapefruit peel (GP) respectively, for 14 days. Locomotor performance and memory index were assessed via negative geotaxis and aversive phototaxis suppression assays, respectively. Thereafter, the fly homogenates were assayed for activities of acetylcholinesterase (AChE), monoamine oxidase (MAO) and antioxidant enzymes as well as other indices of their redox. The results revealed that the citrus peels significantly improved longevity, locomotor performance, memory index, antioxidant status, and modulate cholinesterase and monoamine oxidase enzyme activities in treated flies when compared to the control. The results obtained suggest that the citrus peels offer potentials as dietary supplement with life span promoting properties in D. melanogaster model which could as well serve as a functional food additives. PRACTICAL APPLICATIONS: Citrus peels, although often considered agro-wastes, are used as food supplements and food ingredents especially in production of candies, jams and custards. This study suggests the use of orange (Citrus sinensis), tangerine (Citrus maxima), and grapefruit (Citrus paradisi) peels as dietary supplements which offers potential life span promoting properties.

Effects of GrandFusion Diet on Cognitive Impairment in Transgenic Mouse Model of Alzheimer's Disease

Alzheimer’s disease (AD) is the result of the deposition of amyloid β (Aβ) peptide into amyloid fibrils and tau into neurofibrillary tangles. At the present time, there are no possible treatments for the disease. We have recently shown that diets enriched in phytonutrients show protection or limit the extent of damage in a number of neurological disorders. GrandFusion (GF) diets have attenuated the outcomes in animal models of traumatic brain injury, cerebral ischemia, and chronic traumatic encephalopathy. In this study, we investigated the effect of GF diets in a mouse model of AD prior to the development of amyloid plaques to show how this treatment paradigm would alter the accumulation of Aβ peptide and related pathologic changes (i.e., inflammation, cathepsin B, and memory impairment). Administration of GF diets (2–4%) over a period of four months in APP/ΔPS1 double-transgenic mice resulted in attenuation in Aβ peptide levels, reduction of amyloid load, and inflammation, increased cathepsin B expression, and improved spatial orientation. Additionally, treatment with GF diets increased nerve growth factor (NGF) levels in the brain and tempered the memory impairment in the animal model. These data suggest that GF diets may alter the development and progression of the mechanisms associated with the disease process to effectively modify AD pathogenesis.

Cohort profile: the Diet and Healthy Aging (DaHA) study in Singapore

How diet is related with cognition and health has not been systematically examined in Asians whose eating habits are very different from their counterparts in the West and the biological mechanisms underlying such links are not well known yet. The diet and healthy aging (DaHA) study is a community-based longitudinal study conducted to examine the role of diet and nutrition in promoting cognitive, emotional, and physical health among community-living elderly Singaporeans. The first wave of DaHA, conducted from 2011 to 2017, provided detailed information on diet and baseline cognitive function and health from 1010 community-living elderly in Singapore. Biomarkers of oxidative stress, systemic inflammation, and genetic information were collected. The ongoing second wave of DaHA is conducted from 2017 to 2020, which provides follow- up assessments using established cognitive tests and clinical tools. This well-characterized cohort, with its archived biological samples and high-quality data on diet and lifestyle factors will allow researchers to explore the relationships among diet, nutrition, genes, cognition, mental and physical health in an extremely cost-effective manner. Translations of the research findings into clinical and public health practices will potentially help to promote cognitive health at the population level and reduce healthcare costs related to cognitive impairment.

[1,2,4]Triazolo[1,5-a]pyrimidine Phosphodiesterase 2A Inhibitors: Structure and Free-Energy Perturbation-Guided Exploration

We describe the hit-to-lead exploration of a [1,2,4]triazolo[1,5-a]pyrimidine phosphodiesterase 2A (PDE2A) inhibitor arising from high-throughput screening. X-ray crystallography enabled structure-guided design, leading to the identification of preferred substructural components. Further rounds of optimization used relative binding free-energy calculations to prioritize different substituents from the large accessible chemical space. The free-energy perturbation (FEP) calculations were performed for 265 putative PDE2A inhibitors, and 100 compounds were synthesized representing a relatively large prospective application providing unexpectedly active molecules with IC₅₀'s from 2340 to 0.89 nM. Lead compound 46 originating from the FEP calculations showed PDE2A inhibition IC₅₀ of 1.3 ± 0.39 nM, ∼100-fold selectivity versus other PDE enzymes, clean cytochrome P450 profile, in vivo target occupancy, and promise for further lead optimization.

Citrus spp. essential oils improve behavioral pattern, repressed cholinesterases and monoamine oxidase activities, and production of reactive species in fruit fly (Drosophila melanogaster) model of Alzheimer's Disease

Much emphasis has been placed on the biological activities of citrus peel's essential oils (CPEOs) against human ailments. This study investigated the effect of Citrus limon and Citrus reticulata peel's essential oils (EOs) on behavioral and neurochemical imbalance in transgenic and Harwish (Wild) fruit flies. Flies were divided into seven groups comprising of the control and those that were fed with 0.1, 0.5, and 1.0 µg/ml of the dietary inclusions of study CPEOs for 7 days. Thereafter, behavioral profile was examined using lethality response and negative geotaxis assays. Effect of the EOs on cholinesterase and monoamine oxidase (MAO) activities, and antioxidative parameters were determined. The result showed a significant improvement of behavioral pattern and biochemical parameters of the flies fed with studied CPEOs inclusive diets. Conclusively, both EOs exert neuroprotective capability by reducing cholinesterases and monoamine activities, and also prevent oxidative stress, which are implicated in neuronal dysfunction in humans. PRACTICAL APPLICATIONS: With the growing increase in the search for safer alternatives, having no side effects, for the management of neurodegenerative diseases, a large proportion of the populace is beginning to find solace in the use of natural products. Also, the wide array of similarities between the humans and the dipteran insects, fruit flies is a perfect organism for the study of neurodegenerative diseases. Therefore, this study presents the neuroprotective potentials of lemon and tangerine peels-derived EOs, and the possibility of their exploration as neuroactive agents and alternative in the management of Alzheimer's disease (AD).

A parallel-group, multicenter randomized, double-blinded, placebo-controlled, phase 2/3, clinical trial to test the efficacy of pyridostigmine bromide at low doses to reduce mortality or invasive mechanical ventilation in adults with severe SARS-CoV-2 infection: the Pyridostigmine In Severe COvid-19 (PISCO) trial protocol

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the causative agent of coronavirus disease 2019 (COVID-19), may lead to severe systemic inflammatory response, pulmonary damage, and even acute respiratory distress syndrome (ARDS). This in turn may result in respiratory failure and in death. Experimentally, acetylcholine (ACh) modulates the acute inflammatory response, a neuro-immune mechanism known as the inflammatory reflex. Recent clinical evidence suggest that electrical and chemical stimulation of the inflammatory reflex may reduce the burden of inflammation in chronic inflammatory diseases. Pyridostigmine (PDG), an ACh-esterase inhibitor (i-ACh-e), increases the half-life of endogenous ACh, therefore mimicking the inflammatory reflex. This clinical trial is aimed at evaluating if add-on of PDG leads to a decrease of invasive mechanical ventilation and death among patients with severe COVID-19.

Methods

A parallel-group, multicenter, randomized, double-blinded, placebo-controlled, phase 2/3 clinical trial to test the efficacy of pyridostigmine bromide 60 mg/day P.O. to reduce the need for invasive mechanical ventilation and mortality in hospitalized patients with severe COVID-19.

Discussion

This study will provide preliminary evidence of whether or not -by decreasing systemic inflammation- add-on PDG can improve clinical outcomes in patients with severe COVID-19.

Trial registration

ClinicalTrials.gov NCT04343963 (registered on April 14, 2020).

Histomorphological evaluations on the frontal cortex extrapyramidal cell layer following administration of N-Acetyl cysteine in aluminum induced neurodegeneration rat model

Aluminum is a potent neurotoxin used in animal models of neurodegenerative diseases like Alzheimer's disease (AD), in which oxidative stress mediates tissue pathogenesis in vivo. N-acetyl cysteine (NAC) is a glutathione precursor with reported antioxidant and neuroprotective potentials. Recent therapy for combating AD is known to provide only symptomatic relief thus necessitating the discovery of new drugs and their mechanism of action. This study was aimed to demonstrate the in vivo neuroprotective effect of NAC against aluminum (Al3+)-induced neuro-degeneration in rats (a model for AD). Twenty- five (25) adult male Wistar rats used for this study were divided into 5 groups: Group A = Control, B = Aluminum chloride (200 mg/kg), C = 1000 mg/kg of NAC + Aluminum chloride (200 mg/kg), D = 1000 mg/kg of NAC, E = Aluminum chloride (200 mg/kg) was orally administered daily for 3 weeks and discontinued for one week. Frontal Cortex harvested for histological analysis using Haematoxylin and Eosin stain, Cresyl Fast Violet stain for Nissl granules and Glial fibrillary acidic protein immunohistochemistry specific for astrocytes. Aluminum significantly induced oxidative stress, coupled with marked neurons necrosis, chromatolysis and gliosis in the frontal cortex, upon NAC administration, there was neuro anti-inflammatory response as seen in the significant reduction in astrocytes expression, neuronal cell death and Nissl body aggregation which attenuates neuropathological deficits induced by Al3+. It was shown that aluminum is a neurotoxin mediating AD-like oxidative stress, NAC has a therapeutic potential associated with its potent in vivo interaction with astrocytes in response to Al3+ neuro-inflammation seen in positive expression of Nissl granules and glial cells in addition to possibility of endogenous glutathione neuroprotection after withdrawal of stress mediator in neurodegeneration. Graphical abstract.

A new acetylcholinesterase allosteric site responsible for binding voluminous negatively charged molecules - the role in the mechanism of AChE inhibition

Acetylcholinesterase (AChE) inhibitors are important in the treatment of neurodegenerative diseases. Two inhibitors, 12-tungstosilicic acid (WSiA) and 12-tungstophosphoric acid (WPA), which have polyoxometalate (POM) type structure, have been shown to inhibit AChE activity in nM concentration. Circular dichroism and tryptophan fluorescence spectroscopy demonstrated that the AChE inhibition was not accompanied by significant changes in the secondary structure of the enzyme. The molecular docking approach has revealed a new allosteric binding site, termed β-allosteric site (β-AS), which is considered responsible for the inhibition of AChE by POMs. To the best of our knowledge, this is the first study reporting a new allosteric site that is considered responsible for AChE inhibition by voluminous and negatively charged molecules such as POMs. The selected POMs were further subjected to genotoxicity testing using human peripheral blood cells as a model system. It was shown that WSiA and WPA induced a mild cytostatic but not genotoxic effects in human lymphocytes, which indicates their potential to be used as medicinal drugs. The identification of non-toxic compounds capable of binding to an allosteric site that so far has not been considered responsible for enzyme inhibition could be fundamental for the development of new drug design strategies and the discovery of more efficient AChE modulators.

Present Algorithms and Future Treatments for Alzheimer's Disease

An estimated 47 million people live with Alzheimer’s disease (AD) and other forms of dementia worldwide. Although no disease-modifying treatments are currently available for AD, earlier diagnosis and proper management of the disease could have considerable impact on patient and caregiver quality of life and functioning. Drugs currently approved for AD treat the cognitive, behavioral, and functional symptoms of the disease and consist of three cholinesterase inhibitors (ChEIs) and the N-methyl-D-aspartate receptor antagonist memantine. Treatment of patients with mild to moderate AD is generally initiated with a ChEI. Patients who show progression of symptoms while on ChEI monotherapy may be switched to another ChEI and/or memantine can be added to the treatment regimen. In recent years, putative disease-modifying therapies have emerged that aim to slow the progression of AD instead of only addressing its symptoms. However, many therapies have failed in clinical trials in patients with established AD, suggesting that, once developed, disease-modifying agents may need to be deployed earlier in the course of illness. The goal of this narrative literature review is to discuss present treatment algorithms and potential future therapies in AD.

Impact of Alzheimer's disease and related dementia diagnosis following treatment for bladder cancer

OBJECTIVES

Our objective was to assess the incidence of Alzheimer's Disease and related dementia diagnosis following treatment for muscle-invasive bladder cancer and impact on survival outcomes.

MATERIALS AND METHODS

A total of 4814 patients diagnosed with clinical stage T2-T4a, N0, M0 bladder cancer between January 1, 2002 to December 31, 2011 using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database were identified. Alzheimer's disease and related dementia diagnosis was identified using International Statistical Classification of Disease-Ninth Edition outpatient and inpatient codes. Incidence of dementia following treatment were calculated and reported as dementia cases per 10,000 person-years. Cox proportional hazards models were used to assess the impact of dementia on survival outcomes.

RESULTS

Of the 4814 patients, 2403 (49.9%) underwent radical cystectomy (RC) and 2411 (50.1%) underwent radiotherapy (RTX) and/or chemotherapy (CTX). Overall, 837 (17.4%) patients developed Alzheimer's disease and related dementia following bladder cancer treatment. There was no significant difference in the incidence of Alzheimer's disease and related dementia following either treatment. Patients diagnosed with Alzheimer's disease and related dementia had worse overall (Hazard Ratio (HR), 2.64; 95% Confidence Interval (CI), 2.41-2.89) and cancer-specific (HR, 2.45; 95% CI, 2.18-2.76) survival than those without a dementia diagnosis following treatment.

CONCLUSION

While we observed no difference in new-onset Alzheimer's disease and related dementia diagnosis following RC or RTX and/or CTX, patients with a Alzheimer's and related dementia diagnosis was associated with worse overall and cancer-specific survival. These findings have important implications for screening and the development of targeted interventions for improving outcomes in older adults following complex cancer treatments, as observed in this bladder cancer population.

Effect of Self-Efficacy on Quality of Life in People With Mild Cognitive Impairment and Mild Dementia: The Mediating Roles of Depression and Anxiety

OBJECTIVES

To examine the mediating effects of depression and anxiety in the relationship between self-efficacy and quality of life among people with mild cognitive impairment (MCI) or mild dementia.

METHOD

A total of 196 patients diagnosed with MCI or dementia due to Alzheimer disease completed structured measures of self-efficacy, quality of life, and depressive and anxiety symptoms. We examined direct and mediated effects by fitting structural equation models to data.

RESULTS

Our analyses supported that the effects of self-efficacy on quality of life may be partially mediated by depression and anxiety. Both anxiety and depression had significant mediating effects, with depression showing a stronger effect.

CONCLUSION

These results suggest that increased self-efficacy may have a positive effect on quality of life in people with MCI or dementia-partly by reducing depression and anxiety. These findings may have important practical implications for tailoring therapeutic interventions.

Lawsonia Inermis Markedly Improves Cognitive Functions in Animal Models and Modulate Oxidative Stress Markers in the Brain

Background and Objective: Medicinal plants represent an important source of alternative medicine for the management of various diseases. The present study was undertaken to assess the potential of Lawsonia inermis ethanol (Li.Et) and chloroform (Li.Chf) extracts as memory-enhancing agents in experimental animals. Materials and Methods: Li.Et and Li.Chf were phytochemically characterized via gas chromatography-mass spectroscopy (GC-MS). Samples were tested for nootropic potentials at doses of 25, 50, 100, 200 mg/kg (per oral in experimental animals (p.o.)). Swiss albino mice of either sex (n = 210) were divided into 21 × 10 groups for each animal model. Memory-enhancing potentials of the samples were assessed using two methods including "without inducing amnesia" and "induction of amnesia" by administration of diazepam (1 mg/kg, intraperitoneally. Piracetam at 400 mg/kg (i.p.) was used as positive control. Cognitive behavioral models including elevated plus maze (EPM) and the passive shock avoidance (PSA) paradigm were used. Biochemical markers of oxidative stress such as glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) levels were analyzed in the brain tissue of treated mice. Results: In 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals scavenging assay, Li.Et and Li.Chf exhibited 70.98 ± 1.56 and 66.99 ± 1.76% inhibitions respectively at 1.28 mg/mL concentration. GCMS results revealed the presence of important phytochemicals. Both samples (Li.Et and Li.Chf) at 25 mg/kg (p.o.) dose significantly (p < 0.05) improved learning and memory as indicated by decline in transfer latency and increase in step down latency in EPM and PSA models respectively. Li.Et and Li.Chf at 25 mg/kg (p.o.) showed considerable increase in GSH (2.75 ± 0.018 ***), SOD (2.61 ± 0.059 ***) and CAT (2.71 ± 0.049 ***) levels as compared to positive and negative control groups. Conclusions: This study provides the preliminary clue that L. inermis may be a potential source of memory-enhancing and anti-oxidant compounds and thus warrant further studies.

Changes in functional brain networks and neurocognitive function in Chinese gynecological cancer patients after chemotherapy: a prospective longitudinal study

Background

Previous neurocognitive assessments in non-central nervous system cancers highlight the high incidence of neurocognitive dysfunction in this study population. However, there have been few studies exploring neurocognitive dysfunction induced by chemotherapy in gynecological cancer patients. This prospective longitudinal study was conducted to assess neurocognitive functioning and functional brain networks in Chinese gynecological cancer patients pre- and post-chemotherapy, while additionally including age-matched healthy subjects as the control group.

Methods

All research participants were evaluated using a resting-state functional magnetic resonance imaging and neurocognition assessment. Behavioral data were conducted using SPSS for descriptive statistics, correlation and comparison analyses. Preprocessing of MRI (Magnetic Resonance Imaging) data and network analyses were performed using GRETNA (Graph Theoretical Network Analysis).

Results

A total of 40 subjects joined this study, with 20 subjects in each group. With the exception of the mean of psychomotor speed, there was no significant difference pre-chemotherapy between patients and healthy controls in neurocognitive test mean scores (Ps > 0.05). During the post-chemotherapy assessment, there were significant differences in the mean scores of neurocognitive tests (including Digit Span tests, verbal memory, immediate recall, delayed recall, and information processing speed tests) (all Ps < 0 .05). Longitudinal graph analysis revealed statistically significant differences in the patient group, with significant decreases in both local efficiency (P < 0.01) and global efficiency (P = 0.04). Lower raw TMT-A scores were significantly associated with lower local efficiency (r = 0.37, P = 0.03). Lower verbal memory scores were statistically significant and associated with lower global efficiency (r = 0.54, P = 0.02) in the patient group, but not in the healthy control group.

Conclusions

This study found that the risk of brain function and neurocognitive changes following chemotherapy could potentially guide patients in making appropriate treatment decisions, and this study may identify a cohort that could be suited for study of an intervention.

GM6 Attenuates Alzheimer's Disease Pathology in APP Mice

Alzheimer's disease (AD) results in the deposition of amyloid β (Aβ) peptide into amyloid fibrils and tau into neurofibrillary tangles. Regardless of whether or not these entities are a cause or consequence of the disease process, preventing their accumulation or accelerating their clearance may slow the rate of AD onset. Motoneuronotrophic factor (MNTF) is an endogenous neurotrophin that is specific for the human nervous system, and some of the observed effects of MNTF include motoneuron differentiation, maintenance, survival, and reinnervation of target muscles and organs. GM6 is a six-amino-acid component of MNTF that appears to replicate its activity spectrum. In this study, we investigated the effect of GM6 in a mouse model of AD before the development of amyloid plaques and determined how this treatment affected the accumulation of Aβ peptide and related pathologic changes (e.g., inflammation, nerve growth factor (NGF) expression, cathepsin B, and memory impairment). Application of GM6 over a 4-month period in young APP/ΔPS1 double-transgenic mice resulted in attenuation in Aβ peptide levels, reduction of inflammation and amyloid load, increased cathepsin B expression, and improved spatial orientation. In addition, treatment with GM6 increased brain NGF levels and tempered memory impairment by ∼ 50% at the highest dose. These data suggest that GM6 may modulate disease-determining pathways at an early stage to slow the histological and clinical progression of AD.

Perceptions of Chinese Towards Dementia in Hong Kong-Diagnosis, Symptoms and Impacts

The increasing prevalence of dementia has become a public health issue worldwide including China. This study aims to explore the perception of Chinese in Hong Kong towards the diagnosis, symptoms and impacts of dementia. A cross-sectional survey was conducted among outpatients (without diagnosed dementia) attending a regional public hospital using a standard questionnaire. The results from 290 respondents showed that most preferred to be told about the diagnosis of dementia as soon as possible if they got it, in order to deal with the news and to access treatment and support early. Nearly two thirds of the respondents perceived practical issues (61.3%), physical health (61.0%), and emotional distress (58.4%) as their most fearful impacts, while legal issues (7.4%) were their least concerns. Family history/genes (79.1%) and brain injury (75.9%) were the most commonly perceived causes of dementia. For symptoms, respondents were more likely to identify cognitive impairments than undesirable behaviours. The accepting and proactive attitudes of the public indicate that there is a timely need of more public education about the disease, early screening and better continuity of care to fulfil the anticipated increase of the dementia patient population.

Early detection of dementia: The knowledge and attitudes of primary care physicians in Hong Kong

Background

Dementia affects people worldwide and its prevalence is growing. Early detection of dementia by primary care physicians can be beneficial; thus, their knowledge and attitudes about this issue are important.

Objective

To assess primary care physicians’ knowledge and attitudes about the early detection of dementia in Hong Kong.

Methods

This was a mixed methods (qualitative and quantitative) study. Four focus groups with a purposive sample of 31 primary care physicians were interviewed, and a questionnaire-survey was completed and returned by 437 primary care physicians.

Results

Participants all agreed that the early detection of dementia would benefit patients and primary care physicians should be capable of making such diagnoses. Confidence in making an early diagnosis varied; physicians tended to overlook symptoms in the early stages. All agreed that more training is needed at the post-graduate level of medical education.

Conclusions

Participants had positive attitudes towards early detection of dementia; however, their confidence and ability to make an early diagnosis varied.

Effects of Acupuncture on Cancer-Related Cognitive Impairment in Chinese Gynecological Cancer Patients: A Pilot Cohort Study

Background: Among women in China, gynecological cancers are the second most common cancers after breast cancer. Cancer-related cognitive impairment (CRCI) has emerged as a significant problem affecting gynecological cancer survivors. While acupuncture has been used in different aspects of cancer care, the possible positive effects of acupuncture on cognitive impairment have received little attention. This study hypothesized that patients would demonstrate lower neurocognitive performance and lower structural connectivity compared to healthy controls. This pilot study also hypothesized that acupuncture may potentially be effective in treating CRCI of cancer patients by increasing brain structural connectivity and integrity. Methods: This prospective cohort study consisted of 3 stages: the first stage included a group of gynecological cancer patients and a group of age-matched healthy controls. This baseline stage used a core set of neurocognitive tests to screen patients with cognitive impairment and used a multimodal approach of brain magnetic resonance imaging (MRI) to explore the possible neurobiological mechanism of cognitive impairment in cancer patients, comparing the results with a group of noncancer controls. The second stage involved assigning CRCI patients into the acupuncture intervention group, while patients without CRCI were assigned into the cancer control group. The third stage was a postintervention assessment of neurocognitive function by the same set of neurocognitive tests at baseline. To explore the possible neurobiological basis of acupuncture for treating CRCI, this study also used a multimodal MRI approach to assess changes in brain structural connectivity, and neurochemical properties in patients at pre- and postacupuncture intervention. Results: This study found that the prevalence of cognitive impairment in Chinese gynecological cancer patients at diagnosis was 26.67%. When investigating the microstructural white matter in the brain, diffusion tensor imaging data in this study indicated that premorbid cognitive functioning (before clinical manifestations become evident) has already existed, as the global and local connectome properties in the entire patient group were lower than in the healthy control group. Using magnetic resonance spectroscopy, this study indicated there was a significant reduction of relative concentration of NAA (N-acetyl aspartate) in the left hippocampus, comparing these results with healthy controls. Regarding the effects of acupuncture on reducing CRCI, patients in the acupuncture group reported better neurocognitive test performance after matching for age, menopausal status, cancer stage, and chemotherapy regimen dosage. On a microstructural level, acupuncture’s ability to reduce CRCI may be attributed to a reduction in demyelination and an enhancement of the neuronal viability of white matter in the hippocampus. Conclusion: This pilot study indicates that acupuncture is a promising intervention in treating CRCI in gynecological cancer patients undergoing chemotherapy; however, it requires evaluation in larger randomized controlled studies to definitively assess its benefit. By using a multimodal imaging approach, this pilot study also provides novel insights into the neurobiological basis of cognitive impairment on the human brain that has been induced by cancer and/or its treatment.

Cerebral Responses to Acupuncture at GV24 and Bilateral GB13 in Rat Models of Alzheimer's Disease

Acupuncture has been widely used in China to treat neurological diseases including Alzheimer's disease (AD). However, its mechanism remains unclear. In the present study, eighty healthy Wistar rats were divided into a normal control group (n = 15) and premodel group (n = 65). Forty-five rats that met the criteria for the AD model were then randomly divided into the model group (MG), the nonacupoint group (NG), and the acupoint group (AG). All rats received positron emission tomography (PET) scanning, and the images were analyzed with Statistical Parametric Mapping 8.0. MG exhibited hypometabolism in the olfactory bulb, insular cortex, orbital cortex, prelimbic cortex, striatum, parietal association cortex, visual cortex, cingulate gyrus, and retrosplenial cortex. AG exhibited prominent and extensive hypermetabolism in the thalamus, hypothalamus, bed nucleus of the stria terminalis, cerebral peduncle, midbrain tegmentum, and pontine tegmentum compared to NG. These results demonstrated that acupuncturing at GV24 and bilateral GB13 acupoints may improve the learning and memory abilities of the AD rats, probably via altering cerebral glucose metabolism (CGM) in the hypothalamus, thalamus, and brain stem. The observed effects of acupuncture may be caused by regulating the distribution of certain kinds of neurotransmitters and enhancing synaptic plasticity.

Efficacy and safety of a novel acetylcholinesterase inhibitor octohydroaminoacridine in mild-to-moderate Alzheimer's disease: a Phase II multicenter randomised controlled trial

Background

inhibition of acetylcholinesterase (AChE) has been a effective treatment for Alzheimer's disease (AD). Octohydroaminoacridine, a new AChE inhibitor, is a potential treatment for AD.

Method

we conducted a multicenter, randomised, double blind, placebo-controlled, parallel-group Phase II clinical trial to investigate the effects of octohydroaminoacridine in patients with mild-to-moderate AD. Patients were randomised to receive placebo thrice daily, octohydroaminoacridine 1 mg/thrice daily (TID) (low-dose group), 2 mg/TID (middle-dose group) or 4 mg/TID (high-dose group). Doses in the middle-dose and high-dose group were titrated over 2-4 weeks. Changes from baseline to Week 16 were assessed with the AD Assessment Scale-Cognitive Subscale (ADAS-cog), Clinician's Interview-Based Impression of Change Plus (CIBIC+), activities of daily living (ADL) and the neuropsychiatric inventory (NPI). ADAS-cog was the primary end point of the study. A two-way analysis of covariance and least squares mean t-test were used.

Results

at Week 16, the changes from baseline in ADAS-cog were 1.4, -2.1, -2.2 and -4.2 for placebo, low-, middle- and high-dose groups, respectively. Patients in the high-dose group had better performance in CIBIC+ and ADL scores at the end of the study. There was no significant difference in the change in NPI score among the groups. The effects of octohydroaminoacridine were dose dependent, and were effective within 16 weeks of treatment. No evidence was found for more adverse events that occurred in different drug groups than placebo group.

Conclusions

octohydroaminoacridine significantly improved cognitive function and behaviour in patients with mild-to-moderate AD and this effect was dose dependent.

Traumatic Brain Injury Alters the Metabolism and Facilitates Alzheimer's Disease in a Murine Model

A majority of Alzheimer's disease (AD) cases are sporadic without known cause. People who suffered from traumatic brain injury (TBI) are more likely to develop neurodegeneration and cognitive impairments. However, the role of TBI in pathophysiology of AD remains elusive. The present study intended to explore the effect of TBI on metabolism and its role in AD pathogenesis. We subjected double transgenic AD model mice APP23/PS45 to TBI. We found that TBI promoted β-secretase cleavage of amyloid β precursor protein and amyloid β protein deposition, and exuberated the cognitive impairments in AD mouse models. ¹H nuclear magnetic resonance (¹H-NMR)-based metabolomics with multivariate analysis was performed to investigate the characteristic metabolites and the related metabolic pathways in the serum and urine samples of the mice. TBI affected the metabolic patterns, methylamine metabolism, and amino acid metabolism in serum samples. Urinary metabolites showed that glycolysis and the tricarboxylic acid (TCA) cycle were perturbed. The results indicate that TBI might facilitate Alzheimer's pathogenesis by altering metabolism and inducing mitochondrial dysfunction. The study suggests that metabolite changes could also serve as biomarkers for TBI-induced neurodegeneration.

Cognitive Status of Older Adults on Admission to a Skilled Nursing Facility According to a Hospital Discharge Diagnosis of Dementia

OBJECTIVE

Describe the cognitive status on admission to a skilled nursing facility (SNF) according to a hospital discharge diagnosis of dementia in a national sample of Medicare beneficiaries.

DESIGN

Retrospective cohort design.

SETTING

SNFs in the United States.

PARTICIPANTS

Medicare-fee-for-service beneficiaries newly admitted to an SNF within 3 days of discharge from an acute hospital during 2013-2014 (n = 1,885,015).

MEASUREMENTS

Beneficiaries with a discharge diagnosis of dementia were identified using ICD-9 CM codes from the Medicare Provider Analysis and Review (MedPAR) Part A file. Cognitive status at SNF admission was classified as cognitively intact, mildly impaired, moderately impaired, or severely impaired according to the Cognitive Function Scale using items in the Minimum Data Set 3.0.

RESULTS

For beneficiaries with a discharge diagnosis of dementia (n = 252,970), 17.9% were classified as cognitively intact, 25.8% were mildly impaired, and 56.3% were moderately or severely impaired on SNF admission. Approximately 65% of beneficiaries without a hospital diagnosis of dementia were cognitively intact on admission to an SNF, whereas 13.1% were classified as moderately or severely impaired.

CONCLUSION

Medicare beneficiaries with a hospital diagnosis of dementia are often classified as cognitively intact or mildly impaired on admission to an SNF. These findings provide evidence that a hospital diagnosis of dementia might not always reflect cognitive status on admission to an SNF.

Recurrent Epileptic Auras As a Presenting Symptom of Alzheimer's Disease

Seizures are a common co-morbidity during the course of Alzheimer's disease (AD) and in a subset of patients may be one of the presenting symptoms. In this case series, we highlight three patients with recurrent medically refractory epileptic auras whose work up ultimately lead to the diagnosis of AD. All three patients underwent prolonged EEG, serial neuropsychological testing, FDG-PET, cerebrospinal fluid (CSF) AD biomarkers, and MRI. CSF biomarkers were particularly helpful in two cases. These cases highlight the importance of having a high index of suspicion for AD in new onset "idiopathic" epilepsy in the elderly.

Altered resting-state hippocampal functional networks associated with chemotherapy-induced prospective memory impairment in breast cancer survivors

In this study, we aimed to investigate the intrinsic hippocampal functional connectivity (FC) network and its relationship with prospective memory in patients with breast cancer suffering from chemotherapy-induced cognitive impairment (CICI). Thirty-four breast cancer patients before and after adjuvant chemotherapy (CB and CC, respectively) and 31 age- and education-matched cognitively normal (CN) women were recruited and subjected to a prospective memory task and a resting-state functional magnetic resonance imaging scan. Seed-based functional connectivity analysis was used to compare the hippocampal FC networks between CC and CN groups. Partial correction analysis was used to examine the association between the hippocampal FC network and prospective memory in the CC group. The cancer group that underwent chemotherapy obtained significantly poorer scores than the CN group on mini-mental state examination, verbal fluency test, digit span, and prospective memory examination. Compared to the CN group, CC group showed increased hippocampal connectivity in the frontal and parietal cortex, precuneus, posterior cingulate cortex, and the cerebellum. In addition, the increasing hippocampal FC networks were negatively correlated with prospective memory performance in the CC group. These findings suggest maladaptive hippocampal functioning as a mechanism underlying the impairment of prospective memory in patients experiencing CICI.

Bone-brain crosstalk and potential associated diseases

Reciprocal relationships between organs are essential to maintain whole body homeostasis. An exciting interplay between two apparently unrelated organs, the bone and the brain, has emerged recently. Indeed, it is now well established that the brain is a powerful regulator of skeletal homeostasis via a complex network of numerous players and pathways. In turn, bone via a bone-derived molecule, osteocalcin, appears as an important factor influencing the central nervous system by regulating brain development and several cognitive functions. In this paper we will discuss this complex and intimate relationship, as well as several pathologic conditions that may reinforce their potential interdependence.

Fun cube based brain gym cognitive function assessment system

The aim of this study is to design and develop a fun cube (FC) based brain gym (BG) cognitive function assessment system using the wireless sensor network and multimedia technologies. The system comprised (1) interaction devices, FCs and a workstation used as interactive tools for collecting and transferring data to the server, (2) a BG information management system responsible for managing the cognitive games and storing test results, and (3) a feedback system used for conducting the analysis of cognitive functions to assist caregivers in screening high risk groups with mild cognitive impairment. Three kinds of experiments were performed to evaluate the developed FC-based BG cognitive function assessment system. The experimental results showed that the Pearson correlation coefficient between the system's evaluation outcomes and the traditional Montreal Cognitive Assessment scores was 0.83. The average Technology Acceptance Model 2 score was close to six for 31 elderly subjects. Most subjects considered that the brain games are interesting and the FC human-machine interface is easy to learn and operate. The control group and the cognitive impairment group had statistically significant difference with respect to the accuracy of and the time taken for the brain cognitive function assessment games, including Animal Naming, Color Search, Trail Making Test, Change Blindness, and Forward / Backward Digit Span.

Mitochondria as a therapeutic target in Alzheimer's disease

Alzheimer's disease (AD) remains the most common neurodegenerative disease characterized by β-amyloid protein (Aβ) deposition and memory loss. Studies have shown that mitochondrial dysfunction plays a crucial role in AD, which involves oxidative stress-induced respiratory chain dysfunction, loss of mitochondrial biogenesis, defects of mitochondrial dynamics and mtDNA mutations. Thus mitochondria might serve as drug therapy target for AD. In this article, we first briefly discussed mitochondrial theory in the development of AD, and then we summarized recent advances of mitochondrial abnormalities in AD pathology and introduced a series of drugs and techniques targeting mitochondria. We think that maintaining mitochondrial function may provide a new way of thinking in the treatment of AD.

Malignant progression in parietal-dominant atrophy subtype of Alzheimer's disease occurs independent of onset age

Recently, we reported that earlier stages of Alzheimer's disease (AD) can be categorized into 3 following anatomical subtypes using a hierarchical cluster analysis of cortical thickness across the entire brain: medial temporal-dominant (MT), parietal-dominant (P), and diffuse atrophy (D). The goal of this study was to investigate the rates of cognitive decline in these anatomical subtypes. Of the patients included in the prior study, 100 AD patients (MT, n = 36; P, n = 20; D, n = 44) who underwent follow-up neuropsychological assessments over a 3-year period were included. A linear mixed model analysis was performed to compare the longitudinal changes in neuropsychological test scores. The P subtype exhibited the most rapid cognitive decline in attention, language, visuospatial, memory, and frontal executive function, whereas MT and D subtypes did not differ in their longitudinal decline. When repeating the analyses with early-onset AD, which is known to progress faster than late-onset AD, only the P subtype showed such rapid progression. The P subtype appears to be a unique subtype of AD characterized by an aggressive rate of progression.

Linear Regression with a Randomly Censored Covariate: Application to an Alzheimer's Study

The association between maternal age of onset of dementia and amyloid deposition (measured by in vivo positron emission tomography (PET) imaging) in cognitively normal older offspring is of interest. In a regression model for amyloid, special methods are required due to the random right censoring of the covariate of maternal age of onset of dementia. Prior literature has proposed methods to address the problem of censoring due to assay limit of detection, but not random censoring. We propose imputation methods and a survival regression method that do not require parametric assumptions about the distribution of the censored covariate. Existing imputation methods address missing covariates, but not right censored covariates. In simulation studies, we compare these methods to the simple, but inefficient complete case analysis, and to thresholding approaches. We apply the methods to the Alzheimer's study.

Maternal dementia age at onset in relation to amyloid burden in non-demented elderly offspring

Family history (FH) of dementia is a major risk factor for Alzheimer's disease, particularly when the FH is maternal and when the age of dementia onset (AO) is younger. This study tested whether brain amyloid-beta deposition, measured in vivo with (11)C-Pittsburgh compound B (PiB), was associated with parental dementia and/or younger parental AO. Detailed FH and positron emission tomography (PiB) data were acquired in 147 nondemented aging individuals (mean age 75 ± 8). No participant had both positive maternal and paternal FH. A series of analyses revealed that those with maternal, but not paternal, FH had greater levels of PiB retention in a global cortical region than those without FH. PiB retention in maternal FH was not significantly greater than paternal FH. Younger maternal dementia AO was related to greater PiB retention in offspring, whereas younger paternal dementia AO was not. Overall, results suggest that not only is amyloid-beta burden greater in individuals with maternal FH, but also that the burden is greater in association with younger maternal AO.

Multiple Imputation of a Randomly Censored Covariate Improves Logistic Regression Analysis

Randomly censored covariates arise frequently in epidemiologic studies. The most commonly used methods, including complete case and single imputation or substitution, suffer from inefficiency and bias. They make strong parametric assumptions or they consider limit of detection censoring only. We employ multiple imputation, in conjunction with semi-parametric modeling of the censored covariate, to overcome these shortcomings and to facilitate robust estimation. We develop a multiple imputation approach for randomly censored covariates within the framework of a logistic regression model. We use the non-parametric estimate of the covariate distribution or the semiparametric Cox model estimate in the presence of additional covariates in the model. We evaluate this procedure in simulations, and compare its operating characteristics to those from the complete case analysis and a survival regression approach. We apply the procedures to an Alzheimer's study of the association between amyloid positivity and maternal age of onset of dementia. Multiple imputation achieves lower standard errors and higher power than the complete case approach under heavy and moderate censoring and is comparable under light censoring. The survival regression approach achieves the highest power among all procedures, but does not produce interpretable estimates of association. Multiple imputation offers a favorable alternative to complete case analysis and ad hoc substitution methods in the presence of randomly censored covariates within the framework of logistic regression.

Electroacupuncture at the Baihui acupoint alleviates cognitive impairment and exerts neuroprotective effects by modulating the expression and processing of brain-derived neurotrophic factor in APP/PS1 transgenic mice

Alzheimer's disease (AD) is a common human neurodegenerative disorder characterized by progressive deterioration of cognition and memory. Acupuncture at the Baihui (DU20) acupoint has long been used in China to clinically treat cognitive impairment. However, the precise mechanism underlying its neuroprotective effects remains to be elucidated. In the present study, electroacupuncture (EA) at the Baihui (DU20) acupoint was observed to markedly ameliorate cognitive impairments, reduce the aberrant overexpression of β-amyloid(1-42), and inhibit neuronal apoptosis in APP/PS1 mice. As brain-derived neurotrophic factor (BDNF) has been implicated in the pathogenesis of AD, the expression and processing of BDNF in APP/PS1 mice was investigated. EA at the Baihui (DU20) acupoint was indicated to significantly enhance the expression levels of mature BDNF and proBDNF in APP/PS1 mice. Furthermore, an increase in the BDNF/proBDNF ratio, upregulation of the expression levels of phosphorylated tropomyosin receptor kinase B and a decrease in the expression level of p75 neurotrophin receptor were also observed in the APP/PS1 mice. The present study demonstrates the efficacy of EA at the Baihui (DU20) acupoint in the treatment of cognitive impairments in APP/PS1 transgenic mice. The present study hypothesized that modulation of BDNF expression and processing may be the underlying mechanism by which stimulation of the Baihui (DU20) acupoint exerts its neuroprotective effect.

Pre-training Catechin gavage prevents memory impairment induced by intracerebroventricular streptozotocin in rats

Objective:

To evaluate the effects of Catechin (CAT) on memory acquisition and retrieval in the animal model of sporadic alzheimer’s disease (sAD) induced by intracerebroventricular (icv) injection of streptozotocin (STZ) in passive avoidance memory test.

Methods:

Thirty adult rats were divided into 5 experimental groups (n=6). Animals were treated by icv saline/STZ (3 mg/kg) injection at day one and 3 after cannulation. The STZ+CAT group received 40 mg/kg CAT by daily gavages for 10 days, after icv STZ treatment and before training. The step-through latency (STL) and time spent in the dark compartment (TDC) were evaluated to examine the memory acquisition and retrieval. All tests were performed in Qom University of Medical Sciences, Qom, Iran, from April to December 2013.

Results:

The STZ treatment significantly decreased STL and increased the number of entries to the dark compartment on the training day. It also increased TDC, on day one and 7 after training. Pre-training gavage of CAT reversed the STL significantly (p=0.027). The CAT treatment also decreased the TDC in both early and late retrieval, in respect to STZ group.

Conclusion:

This data suggests that CAT as an antioxidant could improve both memory acquisition and retrieval in the animal model of sAD.

Lifestyle Methods for Prevention of Alzheimer's Disease From the Perspective of Traditional Persian Medicine

Alzheimer's disease is considered as a major problem for society health since it affects interpersonal and social relationships. With regard to the global attention toward complementary medicine, search for preventive, diagnostic, and treatment strategies in complementary medicine schools such as the old dynamic doctrine of traditional Persian medicine seems to be necessary. In this type of medicine, description and analysis of the disease and preventive and treatment methods have great importance. The present study provides a useful classification of recommendations for prevention and control of Alzheimer's disease. Prevention is prior to the treatment and is easier and less costly. Recommendations mentioned in traditional Persian medicine texts for prevention of Alzheimer's disease provide fields of clinical and complementary studies for researches.

Natural β-Dihydroagarofuran-Type Sesquiterpenoids as Cognition-Enhancing and Neuroprotective Agents from Medicinal Plants of the Genus Celastrus

Alzheimer's disease (AD) is an irreversible, multifaceted, and progressive neurodegenerative disorder. Over the past 30 years, the search for anti-AD drugs has been primarily based on the cholinergic deficiency hypothesis and/or the β-amyloid (Aβ) cascade hypothesis. In this study, we report the identification of 16 new and 38 known β-dihydroagarofuran-type sesquiterpenoids from Celastrus flagellaris and Celastrus angulatus. The β-dihydroagarofuran-type sesquiterpenoids 58, 59, 61, and 63 significantly attenuated scopolamine-induced prolonged escape latency and increased number of errors compared with the control group. At 10 μM, 21 of the 62 tested β-dihydroagarofuran-type sesquiterpenoids rescued Aβ25-35-induced SH-SY5Y cells from viability reduction, which increased the cell viability from 64.6% for the model to more than 74.0%. The majority of the β-dihydroagarofuran-type sesquiterpenoids with ester groups exhibited stronger activity than those with free hydroxy groups or without substituents at the same positions. These results identified a new chemical skeleton as drug lead for the investigation of novel therapeutic agents against AD.

Elevated galanin may predict the risk of type 2 diabetes mellitus for development of Alzheimer's disease

Alzheimer's disease is the most common form of dementia among the elderly and is characterized by progressive loss of memory and cognition. Epidemiological and clinical studies demonstrated that type 2 diabetes mellitus is an important risk factor for the development of Alzheimer's disease, i.e., the patients with type 2 diabetes mellitus are frequently companied with Alzheimer's disease symptoms. Despite many studies recently probed into the comorbid state of both diseases, so far the precise mechanism for this association is poorly understood. Emerging evidences suggest that defects in galanin play a central role on type 2 diabetes mellitus and is considered to be a risk factor for Alzheimer's disease development. This review provides a new insight into the multivariate relationship among galanin, type 2 diabetes mellitus and Alzheimer's disease, highlighting the effect of galanin system on the cross-talk between both diseases in human and rodent models. The current data support that activating central GalR2 attenuates insulin resistance and Alzheimer's disease feature in animal models. These may help us better understanding the pathogenesis of both diseases and provide useful hints for the development of novel therapeutic approaches to treat type 2 diabetes mellitus and Alzheimer's disease.

Reduced cerebellar gray matter is a neural signature of physical frailty

Physical frailty has been recognized as a clinical syndrome resulting from declines in various physiological systems; however, the role of the central nervous system in the pathophysiology of frailty remains unclear. The I-Lan Longitudinal Aging Study randomly sampled community-dwelling people aged 50 or older for a brain magnetic resonance imaging study. All participants were assessed for frailty status (robust, prefrail, and frail) based on the presence of five frailty components: slow walking speed, muscle weakness, low physical activity, exhaustion and weight loss (Fried criteria). Gray matter volume (GMV) changes associated with frailty status and individual frailty components were examined. Overall, 456 participants (64.0 ± 8.5 years, 47.6% women) were included in this study. The prefrail (n = 178, 39.0%) and frail (n = 19, 4.2%) subjects were grouped for analysis. The prefrail-frail group showed reduced GMV, compared to the robust group (n = 259, 56.8%), in the cerebellum, hippocampi, middle frontal gyri, and several other cerebral regions (corrected P < 0.05). Each frailty component was associated with GMV changes in functionally related brain areas. Hierarchical cluster analysis categorized these components into three subsets. Motor-related components, including weakness, low activity, and slowness, comprised one subset with a common cerebellar involvement. Exhaustion and weight loss were the other two subsets without cerebellar changes. To conclude, physical frailty is associated with a decreased reserve in specific brain regions, especially cerebellum. Further longitudinal studies are needed to explore if the cerebellum- and noncerebellum-based frailty components reflect a distinctive future risk for developing frailty.

Bone, brain & beyond

In the past 15 years, the field of physiology has been radically challenged by landmark studies using novel tools of genetic engineering. Particular to our interest, the reciprocal interactions between the skeleton and the nervous system were shown to be major ones. The demonstration that brain, via multiple pathways, is a powerful regulator of bone growth, has shed light on an important central regulation of skeletal homeostasis. More recently, it was shown that bone might return the favor to the brain through the secretion of a bone-derived hormone, osteocalcin. The skeleton influences development and cognitive functions of the central nervous system at different stages throughout life suggesting an intimate dialogue between bone and brain.