Modulation of binding properties of amphiphilic DNA containing multiple dodecyl phosphotriester linkages to lipid bilayer membrane.

DNA is a promising functional molecule to modify and design lipid membrane functions. In order to use DNA in a hydrophilic-hydrophobic interface including lipid membrane, we have developed an amphiphilic DNA having dodecyl phosphotriester linkages (dod-DNA). Herein, we report the binding of a series of amphiphilic dod-DNAs to the lipid bilayer membrane. Surface plasmon resonance (SPR) assay and fluorescent microscopy showed that dod-DNA having three dodecyl groups at each end strongly bound to lipid membrane due to the slow dissociation rate and the dod-DNA can be used as a linear template for molecular arrangement on the membrane surface.

Cognitive dysfunction in elderly females with depressive symptoms.

BACKGROUND: A depressive state is a common symptom in the elderly and often accompanies cognitive impairment. The coexistence of depressive symptoms and cognitive impairment is a serious problem, as it increases adverse outcomes for health, functional status, and mortality. It would thus be of great value to clarify the cognitive dysfunction associated with depressive symptoms. We aimed to identify the cognitive dysfunction, in particular, impairment of the response inhibition component of executive function, associated with depressive symptoms in elderly females using the Simple Color Reaction Test and Modified Stroop Color-Word Test. MATERIAL/METHODS: The study group consisted of 35 elderly women. They performed cognitive function task trials for 9 min. Univariate logistic regression analyses were performed to identify factors associated with the prevalence of the depressive state. RESULTS: Longer reaction time and lower correction rate of response inhibition trials were related to the prevalence of the depressive symptoms. CONCLUSIONS: Impaired function of response inhibition may be a specific feature of the depressive state. Our findings may help clarify the neural mechanisms underlying the depressive state of elderly females.

Effect of a human-type communication robot on cognitive function in elderly women living alone.

BACKGROUND: Considering the high prevalence of dementia, it would be of great value to develop effective tools to improve cognitive function. We examined the effects of a human-type communication robot on cognitive function in elderly women living alone. MATERIAL/METHODS: In this study, 34 healthy elderly female volunteers living alone were randomized to living with either a communication robot or a control robot at home for 8 weeks. The shape, voice, and motion features of the communication robot resemble those of a 3-year-old boy, while the control robot was not designed to talk or nod. Before living with the robot and 4 and 8 weeks after living with the robot, experiments were conducted to evaluate a variety of cognitive functions as well as saliva cortisol, sleep, and subjective fatigue, motivation, and healing. RESULTS: The Mini-Mental State Examination score, judgement, and verbal memory function were improved after living with the communication robot; those functions were not altered with the control robot. In addition, the saliva cortisol level was decreased, nocturnal sleeping hours tended to increase, and difficulty in maintaining sleep tended to decrease with the communication robot, although alterations were not shown with the control. The proportions of the participants in whom effects on attenuation of fatigue, enhancement of motivation, and healing could be recognized were higher in the communication robot group relative to the control group. CONCLUSIONS: This study demonstrates that living with a human-type communication robot may be effective for improving cognitive functions in elderly women living alone.