Facial expression recognition in mild cognitive impairment and dementia: is the preservation of happiness recognition hypothesis true?

AIM: Social cognition encompasses facial expression recognition (FER), theory of mind, and empathy. Although studies examining FER in large numbers of patients with mild cognitive impairment (MCI) or dementia are rare, relative preservation of happiness recognition in dementia was reported in some studies. In this study, we examined performance on FER tests and its relationship to clinical demographics and other cognitive function test scores in patients with cognitive decline. METHODS: The present study administered an FER test and several cognitive tests to outpatients at a memory clinic. The FER test presents four facial expressions (happiness, surprise, anger, and sadness). A total of 187 patients were placed in one of the three groups based on their cognitive status: dementia group (n = 63), MCI group (n = 92), and normal cognition group (n = 32). RESULTS: The total scores on the FER test significantly differed among the three groups (normal > MCI > dementia). In the recognition of happiness and surprise, the dementia group had significantly lower scores than the normal cognition group. There were no significant differences in the recognition of anger and sadness scores among the three groups. The FER scores for happiness and surprise were primarily related to executive function scores, but the FER scores for anger and sadness were primarily related to age. CONCLUSIONS: We note the difference in recognition of causative factors among the four emotions (happiness, surprise, anger, sadness). Our study raises serious doubts about the preservation of happiness recognition hypothesis in dementia based on FER tests.

Patient affect and caregiver burden in dementia.

BACKGROUND: Numerous studies focusing on the burden of caregivers of dementia patients have been published. However, there have been few studies focusing on positive affect as an important factor affecting the caregiver burden, and only a few studies comparing the caregiver burden between different dementia diseases have been reported. METHODS: Three hundred and thirty-seven consecutive caregivers of people with dementia participated in this study. The caregiver burden was evaluated by the short version of the Japanese version of the Zarit Burden Interview. RESULTS: Positive affect scores had a significant relationship with the scores of the short version of the Zarit Burden Interview. Caregivers for patients with dementia with Lewy bodies or frontotemporal dementia suffered from a greater burden than those for patients with Alzheimer's disease dementia. CONCLUSIONS: The caregiver burden differed between people caring for patients with different dementia diseases. Positive affect of dementia patients has a significant relationship with caregiver burden, independently from neuropsychiatric symptoms of patients.

Effects of distraction on negative behaviors and salivary α-amylase under mildly stressful medical procedures for brief inpatient children.

Inconsistent results have been reported on the effects of distraction on negative emotions during medical procedures in infants. These differing results may be attributable to the fact that the effects are apparent under a mildly stressful medical procedure. A total of 17 infants, 18 preschoolers, and 15 school-aged children who were hospitalized were administered, monitoring for vital signs, a mildly stressful medical procedure, by a nurse in a uniform with attractive character designs as a distractor. Consistent with the hypothesis, participating infants showed fewer negative behaviors and lower salivary α-amylase levels when distracted. The results support the efficacy of distraction in infants under a mildly stressful medical procedure.

Population dynamics and in situ kinetics of nitrifying bacteria in autotrophic nitrifying biofilms as determined by real-time quantitative PCR.

Population dynamics of ammonia-oxidizing bacteria (AOB) and uncultured Nitrospira-like nitrite-oxidizing bacteria (NOB) dominated in autotrophic nitrifying biofilms were determined by using real-time quantitative polymerase chain reaction (RTQ-PCR) and fluorescence in situ hybridization (FISH). Although two quantitative techniques gave the comparable results, the RTQ-PCR assay was easier and faster than the FISH technique for quantification of both nitrifying bacteria in dense microcolony-forming nitrifying biofilms. Using this RTQ-PCR assay, we could successfully determine the maximum specific growth rate (mu = 0.021/h) of uncultured Nitrospira-like NOB in the suspended enrichment culture. The population dynamics of nitrifying bacteria in the biofilm revealed that once they formed the biofilm, the both nitrifying bacteria grew slower than in planktonic cultures. We also calculated the spatial distributions of average specific growth rates of both nitrifying bacteria in the biofilm based on the concentration profiles of NH4+, NO2-, and O2, which were determined by microelectrodes, and the double-Monod model. This simple model estimation could explain the stratified spatial distribution of AOB and Nitrospira-like NOB in the biofilm. The combination of culture-independent molecular techniques and microelectrode measurements is a very powerful approach to analyze the in situ kinetics and ecophysiology of nitrifying bacteria including uncultured Nitrospira-like NOB in complex biofilm communities.

Protein interactions and misfolding analyzed by AFM force spectroscopy.

Protein misfolding is conformational transition dramatically facilitating the assembly of protein molecules into aggregates of various morphologies. Spontaneous formation of specific aggregates, mostly amyloid fibrils, was initially believed to be limited to proteins involved in the development of amyloidoses. However, recent studies show that, depending on conditions, the majority of proteins undergo structural transitions leading to the appearance of amyloidogenic intermediates followed by aggregate formation. Various techniques have been used to characterize the protein misfolding facilitating the aggregation process, but no direct evidence as to how such a conformational transition increases the intermolecular interactions has been obtained as of yet. We have applied atomic force microscopy (AFM) to follow the interaction between protein molecules as a function of pH. These studies were performed for three unrelated and structurally distinctive proteins, alpha-synuclein, amyloid beta-peptide (Abeta) and lysozyme. It was shown that the attractive force between homologous protein molecules is minimal at physiological pH and increases dramatically at acidic pH. Moreover, the dependence of the pulling forces is sharp, suggesting a pH-dependent conformational transition within the protein. Parallel circular dichroism (CD) measurements performed for alpha-synuclein and Abeta revealed that the decrease in pH is accompanied by a sharp conformational transition from a random coil at neutral pH to the more ordered, predominantly beta-sheet, structure at low pH. Importantly, the pH ranges for these conformational transitions coincide with those of pulling forces changes detected by AFM. In addition, protein self-assembly into filamentous aggregates studied by AFM imaging was shown to be facilitated at pH values corresponding to the maximum of pulling forces. Overall, these results indicate that proteins at acidic pH undergo structural transition into conformations responsible for the dramatic increase in interprotein interaction and promoting the formation of protein aggregates.