La respuesta sistémica Th17/IL-17A aparece antes del proceso neurodegenerativo en el hipocampo de ratas expuestas a bajas dosis de ozono

IntroductionExposure to low doses of O₃ leads to a state of oxidative stress. Some studies show that oxidative stress can modulate both the CNS and systemic inflammation, which are important factors in the development of Alzheimer disease (AD).ObjectiveThis study aims to evaluate changes in the frequency of Th17-like cells (CD3⁺CD4⁺IL-17A⁺), the concentration of IL-17A in peripheral blood, and hippocampal immunoreactivity to IL-17A in rats exposed to low doses of O₃.MethodsOne hundred eight male Wistar rats were randomly assigned to 6 groups (n = 18) receiving the following treatments: control (O₃ free) or O₃ exposure (0.25 ppm, 4 hours daily) over 7, 15, 30, 60, and 90 days. Twelve animals from each group were decapitated and a peripheral blood sample was taken to isolate plasma and mononuclear cells. Plasma IL-17A was quantified using LUMINEX, while Th17-like cells were counted using flow cytometry. The remaining 6 rats were deeply anaesthetised and underwent transcardial perfusion for immunohistological study of the hippocampus.ResultsResults show that exposure to O₃ over 7 days resulted in a significant increase in the frequency of Th17-like cells and levels of IL-17A in peripheral blood. However, levels of Th17/IL-17A in peripheral blood were lower at day 15 of exposure. We also observed increased IL-17A in the hippocampus beginning at 30 days of exposure.ConclusionThese results indicate that O₃ induces a short-term, systemic Th17-like/IL-17A effect and an increase of IL-17A in the hippocampal tissue during the chronic neurodegenerative process.     

认知障碍初步评价表信度与效度的初步研究

目的对认知障碍初步评价表(COG-12)在阿尔茨海默病(AD)患者中的信度与效度进行评价。方法选择2013年1¹2月就诊于南京医科大学附属脑科医院老年精神科的AD患者148例为AD组,另选择社区志愿者365例为对照组,2组均接受临床痴呆量表、AD8、简易智能状态检查量表、画钟测验评估和COG-12测评。其中100例AD患者知情者在首次评定1个月内重测COG-12。结果 COG-12的克朗巴赫α系数=0.883,重测信度=0.883(P<0.01)。COG-12各条目评分与总分的相关系数为0.4112月就诊于南京医科大学附属脑科医院老年精神科的AD患者148例为AD组,另选择社区志愿者365例为对照组,2组均接受临床痴呆量表、AD8、简易智能状态检查量表、画钟测验评估和COG-12测评。其中100例AD患者知情者在首次评定1个月内重测COG-12。结果 COG-12的克朗巴赫α系数=0.883,重测信度=0.883(P<0.01)。COG-12各条目评分与总分的相关系数为0.41⁰.79(P<0.05,P<0.01);COG-12总分与简易智能状态检量表、画钟测验呈负相关(r=-0.67,r=-0.27,P<0.01),与临床痴呆量表、AD8总分呈正相关(r=0.80,r=0.81,P<0.01)。COG-12鉴别认知正常与轻度AD患者的ROC曲线下面积=0.902,≥6分为认知损害的界限分值敏感性为90.0%,特异性为82.5%;鉴别轻度与中度AD患者的ROC曲线下面积=0.898,敏感性为90.5%,特异性为76.7%。结论 COG-12具有良好的信度和效度,是快速识别痴呆及评估严重程度敏感而准确的筛查评估工具。     

DHA对APOE4相关阿尔茨海默病影响的研究进展

阿尔茨海默病(AD)是导致老年人痴呆的主要原因。除年龄外,载脂蛋白E (APOE) 4等位基因是散发型AD最强的危险因素。饮食和补充摄入n-3脂肪酸DHA能降低AD的发病风险和改善AD症状。但是相关研究也产生了混乱的和不一致的结果。进一步研究发现,对APOE 4相关AD病人补充DHA的效果可能与补充量和时间、补充对象的疾病严重程度和补充的DHA的形式有关。APOE4携带者在AD临床症状较轻时大高剂量长时间补充DHA是降低AD发病率的有效途径;最好是通过膳食补充磷脂形式的DHA而不是DHA膳食补充。     

The relationship between cognition and depressive symptoms,and factors modifying this association,in Alzheimer’s disease: A multivariate multilevel model

ObjectivesTo examine whether there was a bidirectional association between cognition and depressive symptoms in Alzheimer’s disease (AD), and to explore the role of socio-demographic factors and daily performance in this association.MethodsWe conducted a longitudinal study of 104 community-dwelling patients with confirmed AD from Taiyuan, China. We assessed cognition and depressive symptoms (dependent variables) with the Montreal Cognitive Assessment (MoCA) and the Geriatric Depression Scale-30 (GDS-30), respectively. Socio-demographic information and daily performance were treated as explanatory variables. A multivariate multilevel model was built to investigate the interrelationship between patients’ cognition and depression, as well as the effect of related factors on both outcomes.ResultsMoCA scores were negatively correlated with GDS-30 both at the subject level (correlation coefficient r₃ = −0.68, χ² = 19.26, P < 0.001) and time point level (r₂ = −0.35, χ² = 35.68, P < 0.001) in patients with AD. Multivariate analysis showed several significant factors for cognitive function, including educational level, personality, hobbies, exercise, reading, aluminum utensil use, dietary restriction and hypertension (regression coefficients: 0.60, 0.52, 0.51, 0.48, 0.45, −0.48, 0.67, and −0.74, respectively). Significant factors for depressive symptoms included family status, employment before retirement, homemaking, reading, aluminum utensil use, dietary restriction, and hypertension (regression coefficients: 3.09, −1.33, −1.62, −1.31, 0.96, −1.15, and 1.14, respectively).ConclusionThese findings indicated that cognition was negatively associated with depression in patients with AD, and both were influenced by reading, aluminum utensil use, dietary restriction, and hypertension. Considering patient factors may help to slow the progression of dementia.     

False memories in patients with mild cognitive impairment and mild Alzheimer’s disease dementia: Can cognitive strategies help?

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that presents predominantly with impairments in learning and memory. Patients with AD are also susceptible to false memories, a clinically relevant memory distortion where a patient remembers an incorrect memory that they believe to be true. The use of cognitive strategies to improve memory performance among patients with AD by reducing false memories has taken on added importance given the lack of disease-modifying agents for AD. However, existing evidence suggests that cognitive strategies to reduce false memories in patients with AD are of limited effectiveness, although these strategies may be useful at earlier stages of the disease. The purpose of this review is to examine experimental findings of false memories and associated memory processes in patients with mild cognitive impairment due to AD and mild AD dementia. Cognitive strategies to reduce false memories in these patient populations are also reviewed. Approaches to clinically relevant future research are suggested and discussed.     

Survival time and differences between dementia with Lewy bodies and Alzheimer’s disease following diagnosis: A meta-analysis of longitudinal studies

ObjectiveTo synthesize the evidence across longitudinal studies comparing survival in dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD).MethodsWe conducted a systematic review and meta-analysis of studies comparing survival in clinically diagnosed DLB to AD. Longitudinal cohort studies were identified through a systematic search of major electronic databases from inception to May 2018. A random effects meta-analysis was performed to calculate survival time and relative risk of death.ResultsOverall, 11 studies were identified including 22,952 patients with dementia: 2029 with DLB (mean diagnosis age 76.3; 47% female) compared with 20,923 with AD (mean diagnosis age 77.2; 65.1% female). Average survival time in DLB from diagnosis was 4.11 years (SD ± 4.10) and in AD 5.66 (SD ± 5.32) years, equating to a 1.60 (95% CI: -2.44 to -0.77) years shorter survival in DLB (p < 0.01). Relative risk of death was increased by 1.35 (95%CI: 1.17–1.55) in DLB compared to AD (p < 0.01). Differences in survival were not explained by follow-up time, age at diagnosis, gender, or cognitive score.ConclusionsThere is consistent evidence for higher and earlier mortality in DLB compared to AD. This is important for all stakeholders and underlines the importance of expanding research into DLB.     

Caregiver-Care Recipient Relationship Closeness is Associated With Neuropsychiatric Symptoms in Dementia

Objective

Closer caregiver-care recipient (CG-CR) relationships are associated with better cognitive and functional abilities, activities of daily living (in persons with dementia), and lower informal care costs.

Semantic and syntactic processing of mass and count nouns: Data from dementia

In the present research, we investigated the processing of Italian mass and count nouns and of their semantic and morphosyntactic attributes in people with neurodegenerative disease. The performance of a group of 26 Italian participants with Alzheimer’s disease was studied in a semantic judgment task and a syntactic judgment task. Results were analyzed by means of mixed-effect models, revealing an interaction between task and stimulus category: The probability for correct responses to mass stimuli was significantly lower than that for count stimuli, but only in the semantic task. These findings confirm the major semantic impairment in dementia and suggest that mass nouns have particular features that make them more prone to impairment than count nouns for a progressively degenerating brain.     

东莞市城区老年痴呆流行病调查及相关影响因素分析

目的 调查东莞市城区老年痴呆发病情况及其相关影响因素.方法 采用多级随机整群抽样法对东莞市28个社区进行随机抽查,共抽查居民2348人,并对他们的一般资料及老年痴呆发病率进行调查和统计,同时进行单因素及多因素分析.结果 单因素分析结果表明,年龄、是否独居、性格情况、文化程度、有无遗传史及是否运动为影响老年痴呆发病的主要因素（P＜0.05）.多因素COX分析结果表明,年龄、是否独居、性格情况、文化程度、有无遗传史及是否运动均为影响老年痴呆发病的独立因素.结论 高龄、独居、性格内向、文化程度偏低、缺乏运动及有遗传史的老年人为痴呆发病潜在发病人群.