Elderly Patients with Mild Cognitive Impairment Exhibit Altered Gut Microbiota Profiles.

BACKGROUND: As a transitional state between normal aging and Alzheimer's disease (AD), mild cognitive impairment (MCI) is characterized by a worse cognitive decline than that of natural aging. The association between AD and gut microbiota has been reported in a number of studies; however, microbial research regarding MCI remains limited. METHODS: This study examined 48 participants, of whom 22 were MCI cases and 26 were normal control cases. Fecal samples were collected for 16S ribosomal RNA (rRNA) quantitative arrays and bioinformatics analysis. RESULTS: A principal coordinates analysis (PCoA) and nonmetric multidimensional scaling (NMDS) both demonstrated that the microbial composition of participants with MCI deviated from that of healthy control participants. Multiple bacterial species were significantly increased (e.g., Staphylococcus intermedius) or decreased (e.g., Bacteroides salyersiae) in samples from the MCI group. CONCLUSION: The composition of gut microbiota differed between normal control and MCI cases. This is the first study to identify a signature series of species in the gut microbiota of individuals with MCI. The results provide a new direction for the future development of an early diagnosis and probiotic regimen.

Mutant presenilin2 promotes apoptosis through the p53/miR-34a axis in neuronal cells.

Neurodegenerative disorders have attracted attention in last decades due to their high incidence in the world. The p53/miR-34a axis triggers apoptosis and suppresses viability in multiple types of cells, but little is known about its role in neurodegenerative diseases. In this study, we showed that presenilin (PS)-2, a major gene associated with familial Alzheimer's disease (AD) could trigger the apoptosis through the p53/miR-34a axis in PC12 cells. First we found that PC12 cell viability was downregulated by PS-2 and mutant PS-2 overexpression, especially by mutant PS-2 overexpression. Then, we established a mutant PS-2-overexpressing PC12 cell line and confirmed that mutant PS-2 induced not only p53 but also miR-34a expression. The transfection of miR-34a inhibitor reversed PS-2-induced effects on cellular viability and apoptosis. Mutant PS-2 overexpression promoted caspase-3 expression, reduced Sirt1 and Bcl-2 expression, all of which were miR-34a downstream genes related with cell apoptosis. Moreover, mutant PS-2 also activated the p53/miR-34a axis and induced apoptosis in AD transgenic mice brain. These results implied that mutant PS-2 might promote the apoptosis of neuronal cells through triggering the p53/miR-34a axis. Altogether our results provide a novel insight into neurodegenerative disease and deepen our understandings of AD pathogenic processes.

[Effects of sleep deprivation on the intelligence structure of school-age children in Changsha, China].

OBJECTIVE: To investigate the effects of sleep deprivation on intelligence development in primary school students. METHODS: Between June 2009 and April 2010, 316 grade 5 students aged 10-11 years were selected from four primary schools in four administrative districts of Changsha, China by stratified random sampling. The intelligence characteristics of children with varying degrees of sleep deprivation were investigated using the Chinese Wechsler Intelligence Scale for Children. RESULTS: A total of 286 valid questionnaires were received, with a response rate of 90.5%. The survey was comprised of a sleep deprivation group (sleep time <8 hours per night; n=180) and a control group (sleep time ≥8 hours per night; n=106). The sleep deprivation group had significantly lower subtest scores, verbal intelligence quotient (IQ) (VIQ), performance IQ (PIQ) and full scale IQ (P<0.05) and significantly lower verbal comprehension factor score and memory/attention factor score compared with the control group (P<0.05). Compared with the control group, the moderate sleep deprivation subgroup had significantly decreased VIQ and full scale IQ as well as verbal comprehension factor score and memory/attention factor score (P<0.05), and the severe sleep deprivation subgroup showed decreases in all scores (P<0.05). The sleep deprivation group and moderate and severe sleep deprivation subgroups had significantly higher proportions of children with VIQ-PIQ imbalance than the control group. CONCLUSIONS: Sleep deprivation adversely affects intelligence development, especially VIQ, in primary school students, and the adverse effects of sleep deprivation are mainly seen in students with moderate and severe sleep deprivation.

Reliability, validity, and optimal cutoff score of the montreal cognitive assessment (changsha version) in ischemic cerebrovascular disease patients of hunan province, china.

BACKGROUND/AIMS: The goal of this study was to examine the reliability and validity of the Changsha version of the Montreal Cognitive Assessment (MoCA-CS) in ischemic cerebrovascular disease patients of Hunan Province, China, and to explore the optimal cutoff score for detecting vascular cognitive impairment-no dementia (VCI-ND) and vascular dementia (VD). METHODS: Three hundred and thirty-eight ischemic cerebrovascular disease patients (131 with normal cognition, 111 with VCI-ND, and 96 with VD) and 132 healthy controls were recruited. All participants accepted examination by the MoCA-CS, Mini-Mental State Examination (MMSE), and other related scales. A detailed neuropsychological battery was used for making a final cognitive diagnosis. SPSS 16.0 statistical software was used for reliability, validity examination, and optimal cutoff score detection. RESULTS: Cronbach's α of the MoCA-CS was 0.884, and test-retest and interrater reliability of the MoCA-CS were 0.966 and 0.926, respectively. MoCA-CS scores were highly correlated with MMSE scores (r = 0.867) and simplified intelligence quotients (r = 0.822). The results indicate that 1 point should be added for subjects with less than 6 years of education, and that the optimal cutoff score for detecting VCI-ND is 26/27 (sensitivity 96.1%, specificity 75.6%), whereas the optimal cutoff score for detecting VD is 16/17 (sensitivity 92.7%, specificity 96.3%). CONCLUSION: The MoCA-CS has good reliability and validity, and is a useful cognitive screening instrument for detecting VCI in the Chinese population.