Perceptual and response interference in Alzheimer’s disease and mild cognitive impairment

Objectives

The ability to resolve conflicts is indispensable to the function of daily life and decreases with cognitive decline. We hypothesized that subjects with different levels of cognitive impairment exhibit different conflict resolution performances and may be susceptible to interference effects at different stages.

Methods

Sixteen normal controls (NC), 15 mild cognitive impairment (MCI) and seven Alzheimer’s disease (AD) patients were recruited to perform in a modified Eriksen flanker task.

Results

We observed that the AD and MCI patients exhibited smaller accuracy rate and longer response time compared to NC subjects. Longer N2 and P300 latencies were observed in the AD group. Furthermore, the MCI group showed a longer latency than the NC group in the P300 latency. The magnitude of the perceptual and response interference effects was larger in the AD group than the other groups, and the MCI group significantly differed from the NC group at the perceptual level.

Conclusion

The ability to resolve conflict decreased with impaired cognition and the perceptual and response interference effects may be useful in distinguishing MCI and AD.

Significance

The perceptual or response interference effect may potentially be employed as a useful non-invasive probe for the clinical diagnosis of MCI and AD.     

肝脏表达Niemann-Pick C1-Like 1调节肝X受体诱导的小鼠胆固醇分泌

目的:探讨小鼠肝脏过表达人NPC1L1对LXR诱导的小鼠胆固醇分泌的影响。方法:给予野生型小鼠(WT)和肝脏过表达人NPC1L1的转基因小鼠(L1Tg)胃饲LXR激动剂(T0901317)7 d后,抽提小鼠粪便总脂质并检测核心甾醇的含量,检测小鼠的血浆脂质水平,分析肝脏ABCG5和ABCG8的mRNA表达水平。结果:L1Tg小鼠与WT小鼠相比,除血浆游离胆固醇含量显著升高外,粪便核心甾醇含量及肝脏ABCG5和G8的mRNA水平差异无统计学意义;在胃饲T0901317 1 w后,WT小鼠的粪便核心甾醇含量由[(3.22±0.44)升高到(28.68±1.05)μmol.d-1.100 g-1],血浆总胆固醇、游离胆固醇、胆固醇酯和磷脂的含量均显著升高,同时肝脏的ABCG5和G8的mRNA水平也分别上调了5倍和2倍;然而,L1Tg小鼠经T0901317处理后,与T0901317处理的WT小鼠相比,粪便核心甾醇的分泌减少了56%,血浆游离胆固醇含量升高了40%,肝脏的ABCG5和G8的mRNA水平分别降低了52.4%和40.6%。结论:肝脏特异表达人NPC1L1降低了LXR诱导的小鼠粪便核心甾醇的分泌,并升高了血浆游离胆固醇水平,可能与下调LXR诱导的肝脏ABCG5和G8 mRNA表述水平有一定关系。     

血清可替宁水平与冠心病的关系

目的研究血清可替宁水平与冠心病的关系,探讨其在冠心病中的临床应用价值。方法按冠状动脉造影结果将149例研究对象分为冠心病组(97例)和非冠心病对照组(52例),进行病例对照研究,同位素稀释串联质谱法(isotope dilution tandem mass spectrometry,ID-LC/MS/MS)测定血清可替宁浓度,分析可替宁与冠心病及其他危险因素的关系。结果 149例行冠状动脉造影患者血清可替宁浓度呈偏态和尖态分布(偏度2.90,峰度7.96),吸烟者的可替宁浓度为12.64(0.91～99.61)μg/L,显著高于非吸烟者[0.22(0.12～0.51)μg/L,P<0.001]。高可替宁水平组(>10.00μg/L)患冠心病的风险显著高于低可替宁水平组(<1.00μg/L)(OR=2.94,95%CI:1.11～7.78,P<0.05);且随着血清可替宁水平的升高,OR值增大呈量效关系(均为P<0.05)。多因素Logistic回归分析显示,糖尿病、血脂异常及可替宁为最显著的危险因素(均为P<0.05)。血清可替宁与吸烟(r=0.656,P<0.001)和白细胞计数(WBC,r=0.257,P=0.010)呈显著正相关,与HDL-C(r=-0.184,P=0.025)和HDL2-C(r=-0.217,P=0.008)呈显著负相关。结论血清可替宁水平能够有效地反映吸烟的暴露水平,其水平升高能够增加患冠心病的危险。     

PREVALENCE AND CHARACTERISTICS OF HIV-ASSOCIATED STROKE IN A TERTIARY HOSPITAL SETTING IN SOUTH AFRICA

Background and AimsAntiretroviral treatment (ART) era HIV-associated stroke data from Sub-Saharan Africa is limited. We determined the prevalence of HIV in patients presenting with acute symptomatic stroke; and compared risk factors, clinical characteristics, and brain imaging with age-matched stroke patients without HIV.MethodsWe conducted a retrospective study of adults presenting with any type of stroke to a South African tertiary hospital in a 12-month period. Patients living with HIV (PLWH) and HIV-uninfected patients (HIV-) were matched on age group (1:2 ratio).ResultsTheacute stroke prevalence of HIV infection was 9.3% (95%CI: 7.4-11.2%) among 884 stroke patients. Mean age at presentation in PLWH was 46 (±11) years compared to 55 (±14) years in HIV- (p<0.001). Hypertension (p=0.011) and dyslipidaemia (p=0.005) were less prevalent in PLWH. Concurrent infection was more prevalent in PLWH (p=<0.001), largely in patients with low CD4 counts. PLWH with higher CD4 counts had traditional risk factors and less concurrent infection. Among PLWH, 39.3% had been started / restarted on ART within 6-months. Basal ganglia infarcts (p=0.014) and multiple vascular territory involvement (p=0.002) was more common in PLWH. Clinical presentation, ischaemic stroke type, and in-hospital outcomes did not differ between groups.ConclusionStroke patients with HIV were younger, had less traditional cardiovascular risk factors, and more concurrent infections than patients without HIV when CD4 count was low. Recent ART initiation or reinitiation rates were high. Significant differences in CT brain imaging findings were seen. Understanding the multifactorial mechanisms underlying increased stroke risk in this population is crucial.     

Trends in Prevalence of Serious Psychological Distress and Depression Among Adults with Stroke in the United States

ObjectivesTo examine national trends in prevalence of serious psychological distress and depression among adults with stroke in the United States (US) from 2004 to 2017, and variations across sociodemographic subgroups.MethodsData were obtained from the household components of the 2004-2017 Medical Expenditure Panel Survey, a nationally representative survey in the US. History of stroke or transient ischemic attack was based on self-report. Psychological distress was measured by the Kessler-6 scale, and depressive symptoms were measured by the 2-item Patient Health Questionnaire. Logistic regression models were used to examine the trends in prevalence of serious psychological distress and depression overall and by age, sex, and race/ethnicity.ResultsAmong 10889 participants with stroke or transient ischemic attack, 60.0% were aged ≥ 65, 54.4% were female, and 72.2% were non-Hispanic white. The prevalence of serious psychological distress decreased from 14.9% in 2004-2005 to 11.3% in 2016-2017, corresponding to 7% lower odds every 2 years (adjusted odds ratio [aOR0.93, 95% confidence interval [CI]=0.89-0.97); and the prevalence of depression decreased from 23.1% in 2004-2005 to 18.3% in 2016-2017, corresponding to 5% lower odds every 2 years (aOR=0.95, 95% CI=0.92-0.98), after adjustment for sociodemographic characteristics, functional limitations, and antidepressant use. The trends varied significantly by age, but not sex and race/ethnicity. The overall decline was mainly driven by older adults above age 64.ConclusionsPrevalence of serious psychological distress and depression among US adults with stroke decreased from 2004 to 2017, but the burden of mental health problems remained high.     

Muscle Oxygenation of the Paretic and Nonparetic Legs During and After Arterial Occlusion in Chronic Stroke

Oxygen delivery and demand are reduced in the paretic leg post-stroke, reflecting decreased vascular function and reduced muscle quantity and quality. However, it is unknown how muscle oxygenation, the balance between muscle oxygen delivery and utilization, is altered in chronic stroke during and after occlusion-induced ischemia.ObjectivesThe objective was to determine muscle oxygen consumption rate, microvascular responsiveness and reactive hyperemia in the paretic and nonparetic legs during and after arterial occlusion post-stroke.Materials and MethodsMuscle oxygen saturation was measured with near-infrared spectroscopy on the vastus lateralis of each leg during 3-minute arterial occlusion and recovery (3 min). Muscle oxygen consumption was derived from the desaturation slope during ischemia, microvascular responsiveness was derived from the resaturation slope after ischemia and reactive hyperemia was derived from the area under the curve above baseline after ischemia. Results: Eleven subjects (91% male; 32.2±6.1 months post-stroke; age 62.9±13.6 years) with a hemiparetic gait pattern participated. There was no significant between-leg muscle oxygenation difference at rest (paretic: 64.9±16.6%; nonparetic: 70.6±15.6%, p = 0.13). Muscle oxygen consumption in the paretic leg (-0.53±0.24%/s) was significantly reduced compared to the nonparetic leg (-0.70±0.36%/s; p = 0.03). Microvascular responsiveness was significantly reduced in the paretic leg compared to the nonparetic leg (paretic: 4.6±1.8%/s; nonparetic: 5.7±1.6%/s, p = 0.04). Reactive hyperemia was not significantly different between legs (paretic:4384±2341%·s; nonparetic: 3040±2216%·s, p = 0.07).ConclusionMuscle oxygen consumption and microvascular responsiveness are impaired in the paretic compared to the nonparetic leg, suggesting both reduced skeletal muscle aerobic function and reduced ability to maximally perfuse muscle tissue.     

An observational epidemiological study to analyze intracerebral hemorrhage across the United States: Incidence and mortality trends from 1990 to 2017

ObjectivesIntracerebral Hemorrhage (ICH) accounts for 10% of strokes annually in the United States (US). Up-to-date trends in disease burden and regional variations remain unknown. Our study reports updated trends of ICH incidence, mortality, and mortality to incidence ratio (MIR) across the US.Materials and MethodsObservational study to evaluate the incidence and mortality from ICH across the US. Data was obtained from Global Burden of Disease (GBD) database. Age-Standardized Incidence (ASIRs) and Death (ASDRs) Rates, as well as the Mortality- to-Incidence ratios (MIRs) for ICH in the US overall and state-wise from 1990-2017. Joinpoint regression analysis was used, with presentation of estimated annual percentage changes (EAPCs).ResultsOverall decrease in ASIRs, ASDRs, and MIRs in the US for both sexes. The 2017 mean ASIR was 25.67/100,000 for men and 19.17/100,000 for women, whereas mean ASDR was 13.96/100,000 for men and 11.35/100,000 for women. District of Columbia had greatest decreases in ASIR EAPCs for both men and women at -41.25% and -40.58%, respectively, and greatest decreases in ASDR EAPCs for men and women at -55.38% and -48.51%, respectively. MIR between 1990-2017 decreased in men by -12.12% and women by -7.43%. MIR increased in men from 2014-2017 (EAPC +2.2%) and in women from 2011-2017 (EAPC +1.0%).ConclusionDecreasing trends in incidence, mortality, and MIR. No significant trends in mortality were found in the last 6 years of the study period. MIR worsened in males from 2014-2017 and females from 2011-2017, suggesting decreased ICH-related survival lately.