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Biomedical subjects

T Ono

Publications and source records attributed to T Ono.

At least 19 recordsLinked to original sources
PubMed2025

Impact of Chewing Behavior Change on Cognition and Cerebral Hemodynamics.

BACKGROUND: Impaired chewing ability is a recognized risk factor for cognitive decline in older adults, potentially due to reduced neural stimulation in cognition-related brain regions. While short-term studies have demonstrated transient increases in neural activity from chewing, the sustained cognitive and neurophysiological effects of encouraging thorough chewing habits in daily life remain unclear. OBJECTIVE: This randomized controlled trial investigated whether promoting thorough chewing during meals could improve cognitive function and cerebral hemodynamics in older adults. METHODS: Fifty participants aged 65 y or older were randomly assigned to either a 1-mo intervention group, which used a wearable device to monitor and increase chewing strokes during meals, or a control group that maintained usual chewing habits. Chewing behavior, cognitive performance (including memory and executive function via the color Stroop test), and cerebral hemodynamics in the dorsolateral prefrontal cortex (DLPFC) were measured at baseline and after 1 mo. Statistical analyses included t tests, chi-square tests, 2-way analysis of variance with post hoc tests, Pearson correlations, and generalized linear models to evaluate group differences and associations between chewing and cognitive outcomes. RESULTS: Significant time-by-group interactions were observed for memory, F(1, 48) = 6.24, P = 0.043, and hemodynamic responses in the left DLPFC, F(1, 48) = 6.19, P = 0.013. The intervention group showed increased chewing frequency (P = 0.017), improved memory performance, and reduced left DLPFC responses compared with controls. Chewing frequency was positively correlated with Stroop test scores (r = 0.53, P = 0.010) and negatively with hemodynamic changes in the left DLPFC (r = -0.30, P = 0.040). Although improvements in other cognitive outcomes and hemodynamic measures favored the intervention group, these differences did not reach statistical significance. CONCLUSIONS: Promoting intentional chewing habits for 1 mo may enhance memory-related cognitive performance and neural efficiency in the DLPFC during working memory tasks in older adults. This nonpharmacologic, low-burden strategy warrants further research with longer interventions to support cognitive health and dementia prevention. TRIAL REGISTRATION ID: UMIN000044280Knowledge Transfer Statement:This study demonstrates that promoting thorough chewing habits in older adults can improve memory and enhance neural efficiency in the brain. Encouraging intentional mastication is a simple, nonpharmacologic approach that may help maintain cognitive health and prevent dementia, providing a practical strategy for clinicians and policymakers to support healthy aging.

Humans↗
PubMed2007

Influence of human jaw movement on cerebral blood flow.

Temporal changes in cerebral blood flow induced by jaw movement have yet to be investigated. To assess the influence of pattern and intensity of muscle contraction during jaw movement on task-induced change in cerebral blood flow, we performed bilateral transcranial Doppler ultrasound examination during clenching, gum chewing, and tooth tapping in healthy volunteers. A random-effects model analysis revealed a significant increase in middle cerebral artery blood flow velocity during clenching (high muscle activity) and gum chewing (moderate muscle activity), compared with the preceding rest period; however, such an increase was not detected during tooth tapping (low muscle activity). Cerebral blood flow was greater on the working side during the intensive isometric contraction of the masseter muscle in clenching. These results suggest that task-induced change in cerebral blood flow during jaw movement is influenced by the change in peripheral circulation evoked by muscle contraction.

Adult↗
PubMed2006

The relationship between paired pulse magnetic MEP and surgical prognosis in patients with intractable epilepsy.

PURPOSE: To assess whether paired pulse magnetic motor evoked potential (MEP) can predict surgical prognosis in patients with intractable epilepsy. METHODS: MEP of the unilateral hand muscles were recorded following paired pulse transcranial magnetic stimulation (TMS) of the motor cortex. The interstimulus intervals of paired stimulation were 1-16 ms with a conditioning stimulus that was 90% active motor threshold. Subjects were six patients with temporal lobe epilepsy (TLE) scheduled for anterior temporal lobectomy and three patients with myoclonic or head-drop seizures scheduled for anterior corpus callosotomy, resulting in the unilateralization of epileptic discharges. The hemisphere showing unilateral discharges was defined as the affected hemisphere. The intracortical inhibition and facilitation curve was drawn based on MEP before and after surgery and the relationship between MEP and surgical prognosis was investigated. RESULTS: In five patients with TLE showing class I surgical results (Engel's classification), the affected hemisphere showing cortical hyperexcitability preoperatively was almost normalized after surgery. However, in a patient with class III, the unaffected hemisphere showed cortical hyperexcitability before and after surgery. In the callosotomy group, two patients with excellent outcomes showed the same results as TLE group with class I. CONCLUSIONS: Paired pulse magnetic MEP may provide predictive value in terms of surgical outcome in those patients with intractable epilepsy.

Adolescent↗
PubMed2006

Neuronal responses to a delayed-response delayed-reward go/nogo task in the monkey posterior insular cortex.

Anatomical connections of the insular cortex suggest its involvement in cognition, emotion, memory, and behavioral manifestation. However, there have been few neurophysiological studies on the insular cortex in primates, in relation to such higher cognitive functions. In the present study, neural activity was recorded from the monkey insular cortex during performance of a delayed-response delayed-reward go/nogo task. In this task, visual stimuli indicating go or nogo responses associated with reward (reward trials) and with no reward (no-reward trials) were presented after eye fixation. In the reward trials, the monkey was required to release a button during presentation of the 2nd visual stimuli after a delay period (delay 1). Then, a juice reward was delivered after another delay (delay 2). The results indicated that the neurons responding in each epoch of the task were topographically localized within the insular cortex, consistent with the previous anatomical studies indicating topographical distributions of afferent inputs from other subcortical and cortical sensory areas. Furthermore, some insular neurons 1) nonspecifically responded to the visual cues and during fixation; 2) responded to the visual cues predicting reward and during the delay period before reward delivery; 3) responded differentially in go/nogo trials during the delay 2; and 4) responded around button manipulation. The observed patterns of insular-neuron responses and the correspondence of their topographical localization to those in previous anatomical studies suggest that the insular cortex is involved in attention- and reward-related functions and might monitor and integrate activities of other brain regions during cognition and behavioral manifestation.

Analysis of Variance↗
PubMed2006

Conjunctive effects of reward and behavioral episodes on hippocampal place-differential neurons of rats on a mobile treadmill.

Previous studies reported context (or behavior)-dependent activities of hippocampal place cells, which are suggested to be the neural basis of episodic memory. However, it remains unclear what distinctive items these context-dependent activities encode. We investigated separately the effects of space, locomotion, and episodes with positive/negative reinforcements on activity of place-differential neurons in the hippocampal CA1 area. Rats were placed on a treadmill affixed to a motion stage translocated along a figure 8-shaped track. The track could be navigated by two different routes that shared a common central stem. The stage was paused at the start and end of the routes, where conditioned response tasks with different reinforcements were imposed. As the rats passed the common central stem, some neurons fired differently depending on the route. Comparison of hippocampal spatial firing patterns across different conditions with and without treadmill operation and/or the tasks indicated that these route-dependent spatial firing patterns were sensitive to locomotion, the tasks, and vestibular sensation or visual cues such as optic flow. The results suggest that external sensory inputs, path integration, and reinforcement context are all integrated in the hippocampus, which might provide the neural basis of episodic memory.

Animals↗
PubMed2006

Evaluation of a new fiber-reinforced resin composite.

Efficacy of the usage of an experimental fiber-reinforced composite (FRC) on mechanical properties of an indirect composite was investigated by means of three-point bending and Charpy impact tests. Bond strength between the FRC and the indirect composite was also evaluated by tensile testing. The FRC consisted of a matrix resin with 25% silanized milled glass fiber (11-microm diameter, 150-microm length) and 5% colloidal silica. The values of strain of proportional limit, total strain, and fracture energy of the FRC during the bending test (1.2%, 10.4%, and 41.6 x 10(-3) J) were significantly higher than those of the indirect composite (0.1%, 2.5%, and 11.9 x 10(-3) J). The impact strengths of the 1-mm specimens with FRC ranged from 15.2 to 15.9 kJ/m(2), and were significantly higher than that of the control (3.1 kJ/m(2)). The 2-mm specimens showed significant difference from the control when the FRC thickness was equal or greater than 0.5 mm. The bond strength after the thermocycling was 15.2 MPa, and all of the specimens exhibited cohesive fracture inside the indirect composite. Based upon the results, it was concluded that the FRC tested in this study improved toughness and impact resistance of the indirect composite. The interfacial bonding between the FRC and the indirect composite was strong enough to prevent delamination.

Biocompatible Materials↗
PubMed2006

Insulin resistance and impaired myocardial fatty acid metabolism in dialysis patients with normal coronary arteries.

We investigated whether insulin resistance is associated with impaired cardiac fatty acid metabolism in maintenance hemodialysis patients without coronary artery disease. We studied 55 nondiabetic (63+/-11 years old) and 51 diabetic (61+/-10 years old) hemodialysis patients with normal coronary arteries, using single-photon emission computed tomography (SPECT) with an iodinated fatty acid analogue, iodine-123-beta-methyl iodophenyl-pentadecanoic acid ((123)I-BMIPP), to evaluate cardiac fatty acid metabolism. SPECT imaging was graded regionally from 0 (normal) to 4 (absence of tracer) to calculate a summed score for 17 left ventricular segments. Insulin resistance was determined using the homeostasis model assessment index of insulin resistance (HOMA-IR). HOMA-IR correlated with summed BMIPP score in nondiabetic and diabetic patients. Stepwise multiple regression analysis showed that HOMA-IR was independently associated with BMIPP summed score in nondiabetic (beta=0.774, t=9.218, P=0.0001) and diabetic patients (beta=0.792, t=9.079, P=0.0001). Left ventricular ejection fraction was lower in nondiabetic subjects with BMIPP summed score of at least 6 plus HOMA-IR of at least 4 than in others with lower values for both assessments (53.1+/-13.8%, n=20 vs 67.7+/-9.1%, n=23, P=0.0002); this was also true in diabetic subjects (50.9+/-15.2%, n=24 vs 71.0+/-13.6%, n=11, P=0.0007). Association between insulin resistance and impaired cardiac fatty acid metabolism may contribute to left ventricular dysfunction in patients with maintenance hemodialysis without coronary diseases.

Aged↗
PubMed2006

Effect of diglucosamine on the entrapment of protein into liposomes.

Liposomes, which had entrapped bovine serum albumin (BSA), were modified with diglucosamine by two methods. The liposome was prepared by a freeze-thawing method in the presence of the disaccharide, or the disaccharide was added to the liposome prepared in advance without it. To examine the effects of diglucosamine, the morphology, mean particle size, and zeta potential of both liposomes were compared with those of BSA-entrapping liposome prepared without the disaccharide. Diglucosamine caused no remarkable change in shape and no aggregation of the liposome. The presence of the disaccharide was confirmed on the surfaces of modified liposomes, and the entrapment of BSA into the liposomes was increased by the disaccharide. The entrapment behavior was affected by the way the disaccharide was added, and the difference in the way the BSA was entrapped was also indicated.

Animals↗
PubMed2006

Application of magnetic resonance imaging movie to assess articulatory movement.

OBJECTIVE: To introduce the technique of magnetic resonance imaging (MRI) movie and to propose its feasibility for investigating articulatory movement. SUBJECTS: Five healthy adult females participated in the study. METHODS: Dynamic changes in oropharyngeal structures were assessed with MRI movie during the articulation of a bilabial consonant. RESULTS: Movements of the velum and tongue at a time resolution of 30 ms were complex at the tip of the tongue and the anterior part of the velum. These movements that were seen with a time resolution of 30 ms could not be interpolated or in any way derived from the results obtained with a time resolution of 120 ms. CONCLUSION: The results suggest that MRI movie may be useful in the evaluation of articulation. It is important to reduce the time resolution to 30 ms to obtain images of articulators.

Adult↗
PubMed2006

Coordination of tongue pressure and jaw movement in mastication.

The tongue plays an important role in mastication and swallowing by its contact with the hard palate. Using an experimental palatal plate with 7 pressure sensors, and recording jaw movement using mandibular kinesiography, we assessed, in healthy subjects, the coordination of tongue and jaw movements during the entire masticatory sequence of solids, by measuring tongue pressure against the hard palate. Tongue pressure appeared during the occlusal phase, reached a peak near the start of opening, and disappeared during opening. Specific patterns in order, duration, and magnitude of tongue pressure were seen at the 7 pressure sensors in each chewing stroke. Magnitude and duration were significantly larger in the late stage of chewing (8 strokes before initial swallowing) than in the early stage (until 8 strokes after starting mastication). The normal pattern of tongue contact against the hard palate, control of tongue activity, and coordination with jaw movement during mastication is described.

Adult↗
PubMed2006

Hypermethylation of CpGs in the promoter of the COL1A1 gene in the aged periodontal ligament.

Although the human periodontal ligament shows age-associated histological alterations, the molecular mechanisms are not yet understood. We previously found that COL1A1 gene expression declines with age. In this study, we asked whether DNA methylation in the regulatory region of the gene alters in the aging process, as a possible cause of the decline. The method used was a bisulfite modification of cytosine and nucleotide sequencing of DNA. While the 1st intron region was kept demethylated at young and old ages, the levels of methylation at most CpG sites in the proximal and distal regions of the promoter showed elevation at older ages. Analysis of the data indicates the possible importance of DNA hypermethylation in the promoter region for the age-associated decrease of COL1A1 gene expression.

Adolescent↗
PubMed2006

Restless legs syndrome in hemodialysis patients: health-related quality of life and laboratory data analysis.

AIMS: To compare clinical data, sleep quality and health-related quality of life (HRQOL) with and without RLS in HD patients. MATERIALS AND METHODS: The international RLS study group diagnosis questionnaire was completed by 228 HD patients. The Pittsburg Sleep Quality Index (PSQI) for the evaluation of sleep quality and the Kidney Disease Quality of Life (KDQOL-SF) for the analysis of HRQOL were also used. RESULTS: 53 (23%) patients were diagnosed as RLS. Age and age at the initiation of HD were significantly younger in the RLS group. Serum calcium concentration (Ca) was significantly higher in the RLS group. Sleep quality evaluated by PSQI was significantly lower in the RLS group. In SF-36 domains of KDQOL-SF, bodily pain, general health perceptions, vitality, role functioning emotional, mental health and mental component score were significantly lower in the RLS group. In kidney targeted scales of KDQOL-SF, symptoms/problems, burden of kidney disease, cognitive function, quality of social interaction, sleep and patient satisfaction were significantly lower in the RLS group. CONCLUSION: High Ca was possibly connected to the pathophysiology of RLS which impaired sleep quality as well as HRQOL including mental health and many kidney disease related scales.

Adult↗
PubMed2005

Unambiguous representation of overlapping serial events in the rat hippocampal formation.

The hippocampal formation is suggested to be crucial in unambiguous representation of overlapping temporal sequences in episodic memory. We hypothesized that, if this was true, the hippocampal formation neurons would differentially respond to the same elements even in different temporal sequences. The present study was designed to investigate hippocampal formation CA1 neuronal activity of rats during performance of a conditional delayed stimulus-response association task in which three stimuli were conditionally and serially presented with a delay. In the task, the pairs of the second and third stimuli were overlapped across the trials, but separated by the preceding first stimuli. Conditioned tones coming from one of three possible directions were followed, after a short delay, by one of three pairs of reinforcement series. The pairs consisted of air puff (aversive sensory stimuli) and tube protrusion (which allowed licking sucrose behavior) in the following combinations: air puff-tube protrusion, tube protrusion-tube protrusion and tube protrusion-air puff. The pairs were interposed by a 2 s delay. The three conditioned tone directions were associated with these three pairs in a one-to-one correspondence, and its association was conditional to three possible conditioned tone frequencies (300, 530, and 1,200 Hz). The responses of 107 neurons to the air puff and tube protrusion were analyzed by two-way ANOVA (task condition x reinforcement situation). Of 42 air puff-responsive and 64 tube protrusion-responsive neurons, 36 and 53 displayed significant main effects and/or significant interaction, respectively. Furthermore, neural responses during the delay periods were dependent on the task conditions. The results indicated that the majority of the hippocampal formation neurons showed task condition- and/or reinforcement situation-dependent responses, suggesting a crucial role of the hippocampal formation in representation of overlapping serial events in episodic memory.

Action Potentials↗
PubMed2005

Histone variant macroH2A1.2 is mono-ubiquitinated at its histone domain.

Histone macroH2A1.2 (macroH2A) is an unusual histone H2A variant with a large non-histone macrodomain at its carboxyl terminal. MacroH2A1.2 is enriched in facultative heterochromatin, including inactivated X chromosomes in mammalian females and senescence-associated heterochromatin foci. We show here that a small population of macroH2A1.2 is mono-ubiquitinated in human HeLa cells. Mass spectrometry analysis revealed that the specific targeting sites for the mono-ubiquitination are Lys115 and Lys116 of the histone domain. A corresponding Lys119 conserved in histone H2A is also mono-ubiquitinated by Ring protein in the polycomb group complex. We suggest that the mono-ubiquitination of macroH2A1.2 and histone H2A has similar or synergistic implications, but that the multiple ubiquitination sites in macroH2A1.2 might confer a variety of functions upon macroH2A1.2 to modulate chromatin states.

Amino Acid Sequence↗
PubMed2005

A new three-dimensional automatic bodymarker system for transvaginal ultrasonography.

OBJECTIVE: To evaluate the accuracy and usefulness of a newly developed three-dimensional automatic bodymarker system for transvaginal ultrasonography. METHODS: A bodymarker system which utilizes an electromagnetic field to specify the probe position was developed. Software was written which enabled the positional information of the probe and the ultrasound image to be simultaneously displayed on a personal computer. The bodymarker was displayed as a three-dimensional graphic model. The differences between the estimated and the actual position--i.e. the error--for both position (x, y and z) and angles (azimuth, elevation and roll) of the probe were measured. The movement of the probe was then evaluated in healthy female volunteers and the comparative time required for ultrasound examination was determined. RESULTS: Both the position and the angles of the probe were accurately shown in the computer display. The errors were 1.0 mm and 0.7 degrees (median) for position and angle, respectively. The system was also shown to work well in healthy female volunteers. Calibration of the new system required only 5.0 seconds, compared with an average of 7.6 seconds for the conventional bodymarker. CONCLUSION: The newly developed three-dimensional automatic transvaginal bodymarker system provides an accurate indication of probe position and its tilting angle. It works well in healthy female volunteers and speeds up the examination time. It may be clinically useful for transvaginal ultrasound examination.

Calibration↗
PubMed2005

Morphological brain changes associated with Schneider's first-rank symptoms in schizophrenia: a MRI study.

BACKGROUND: Schneider's first-rank symptoms involve an alienated feature of the sense of one's own mental or physical activity. To clarify the brain morphological basis for the production of these symptoms, volumes of the frontal and medial temporal regions and their clinical correlates were examined in patients with schizophrenia. METHOD: Twenty-two patients with schizophrenia and 44 age- and gender-matched healthy control subjects were included. All patients were in their psychotic episodes with definite Schneiderian symptoms, rated by using the Scale for Assessment of Positive Symptoms. Volumetric measurements of high-resolution magnetic resonance imaging were performed in the prefrontal area, cingulate gyrus, and precentral gyrus, and the medial temporal structures such as the amygdala, hippocampus, and parahippocampal gyrus. RESULTS: Patients had significantly decreased volumes in the cingulate gray matter and the amygdala compared to controls. In the patient group, Schneiderian symptom severity showed significant inverse correlations with volumes of the right posterior cingulate gray matter and of the left anterior parahippocampal gyrus. CONCLUSIONS: Schneiderian symptoms may be associated with morphological abnormalities in the limbic-paralimbic regions such as the cingulate gyrus and parahippocampal gyrus, which possibly serve the self-monitoring function and the coherent storage and reactivation of information.

Adult↗
PubMed2005

Invasive phenotype and apoptosis induction of Plesiomonas shigelloides P-1 strain to Caco-2 cells.

AIMS: The mechanism of the host cell invasion of Plesiomonas shigelloides and its capability to induce apoptosis were investigated. METHODS AND RESULTS: We performed a time course experiment on the bacterial adherence and invasion of the P. shigelloides P-1 strain into Caco-2 cells using an invasion assay and flow cytometry. The adherence of P. shigelloides to the Caco-2 cells was almost completed within 10 min after the infection. Thereafter, P. shigelloides starts internalization within the Caco-2 cells, which was completed within 60 min after the infection. Based on the invasion assay using nocodazole, cytochalasin D, and genistein, it became clear that the mechanism of the internalization depended on the signal transduction followed by the rearrangement of the cytoskeletal protein. Based on the DNA laddering and TUNEL methods, the cytotoxicity of the Caco-2 cells by the invasion of P. shigelloides occurred through the induction of apoptosis. CONCLUSIONS: This work demonstrated that the mechanism of invasion of P. shigelloides into Caco-2 cells and the invasion of P. shigelloides induces apoptotic cell death. SIGNIFICANCE AND IMPACT OF THE STUDY: This work revealed the virulence factor, which may be important for understanding of the pathogenesis of P. shigelloides.

Apoptosis↗