Relationship between maximal isometric tongue pressure and limit of fracture force of gels in tongue squeezing.

BACKGROUND: There is no clear objective indicator for selecting soft foods that are required for food bolus formation in older people with impaired oral function. OBJECTIVE: This study aimed to investigate the relationship between maximal isometric tongue pressure (MITP) and the mechanical properties of gels that can be crushed by the tongue. METHODS: This study included 65 healthy participants aged 22-96 (young group; 15 males, 15 females; older dentate group; 7 males, 8 females; older edentulous group; 10 males, 10 females). MITP was measured by the balloon-probe device. Agar gel with 10 different kinds of fracture force from 10N to 100N was used. The limit of fracture force of gels (LFFG) that were crushed by the tongue was measured by the up-and-down method. In the older edentulous group, two items were measured with and without dentures. Spearman's rank correlation coefficient was used to evaluate the relationship between MITP and LFFG in each group (p < .05). RESULTS: There were positive correlations between MITP and LFFG in all groups (overall groups: rs = .66, young group: rs = .46, older dentate group: rs = .61, older edentulous group with dentures: rs = .60, older edentulous group without dentures: rs = .47). CONCLUSION: MITP and LFFG were positively correlated in young, older dentate and older edentulous groups, suggesting that MITP has the potential to be an objective indicator of the range of mechanical properties of soft food that can be crushed by the tongue.

Subjective-Physiological Coherence during Food Consumption in Older Adults.

BACKGROUND: Subjective-physiological emotional coherence is thought to be associated with enhanced well-being, and a relationship between subjective-physiological emotional coherence and superior nutritional status has been suggested in older populations. However, no study has examined subjective-physiological emotional coherence among older adults while tasting food. Accordingly, the present study compared subjective-physiological emotional coherence during food consumption among older and younger adults. METHODS: Participants consumed bite-sized gel-type foods with different flavors and provided their subjective ratings of the foods while their physiological responses (facial electromyography (EMG) of the corrugator supercilia, masseter, and suprahyoid, and other autonomic nervous system signals) were simultaneously measured. RESULTS: Our primary findings were that (1) the ratings of liking, wanting, and valence were negatively correlated with corrugator EMG activity in older and young adult participants; (2) the positive association between masseter EMG activity and ratings of wanting/valence was weaker in the older than in the young adult group; and (3) arousal ratings were negatively correlated with corrugator EMG activity in the older group only. CONCLUSIONS: These results demonstrate commonalities and differences in subjective-physiological emotional coherence during food intake between older and young adults.

Cerebral blood flow abnormalities with central sparing on arterial spin labeling in mild encephalopathy associated with excitotoxicity: a case report.

BACKGROUND: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and mild encephalopathy associated with excitotoxicity (MEEX) are the most frequent acute encephalopathies in pediatric patients in Japan. AESD typically presents with biphasic seizures and delayed reduced diffusion in the subcortical area, called bright tree appearance (BTA), on radiological examination. In patients with AESD, arterial spin labeling (ASL) shows decreased cerebral blood flow (CBF) in the hyperacute stage and increased CBF in the acute stage, suggesting the usefulness of ASL for the early diagnosis of AESD. Additionally, proton magnetic resonance spectroscopy (MRS) shows elevated glutamate (Glu) and glutamine (Gln) in AESD. MEEX is a group of mild encephalopathies with transient elevation of Gln on MRS similar to that in AESD; however, MEEX does not include any clinical biphasic course or abnormalities, including BTA on diffusion-weighted imaging. Although the usefulness of ASL for AESD has been reported, there are no reports for patients with MEEX. In this study, we report our experience with a 4-year-old girl diagnosed with MEEX who showed unique findings on ASL. CASE PRESENTATION: The patient was a 4-year-old girl admitted to the emergency room with febrile status epilepticus. Considering the possibility of AESD, vitamin therapy was initiated. ASL-MR imaging (MRI) of the brain performed on the second day showed increased blood flow in the frontal, temporal, and occipital regions with spared central sulcus, which indicated AESD with central sparing. The patient was diagnosed with AESD, and the treatment included pulse steroid therapy and immunoglobulin therapy from day 3. The patient remained mildly unconscious but gradually became conscious by day 7 with no seizures. Brain MRI performed on day 8 did not show any characteristic AESD findings, such as BTA. Furthermore, MRS showed elevated Gln, which, along with the clinical course, led to the diagnosis of MEEX. The patient was discharged on day 16 without obvious sequelae. CONCLUSIONS: ASL may be useful in the early diagnosis of MEEX as well as AESD, facilitating early intervention.

Damage-free evaluation of cultured cells based on multivariate analysis with a single-polymer probe.

We present a pattern-recognition-based sensor that targets cell-derived components in culture media and evaluates cultured cells without damaging them. An array sensor made of a single-polymer probe was employed to obtain fluorescence response patterns of the analyte media, allowing successful identification of the type and state of the cells via multivariate analysis.

Polymer-based chemical-nose systems for optical-pattern recognition of gut microbiota.

Gut-microbiota analysis has been recognized as crucial in health management and disease treatment. Metagenomics, a current standard examination method for the gut microbiome, is effective but requires both expertise and significant amounts of general resources. Here, we show highly accessible sensing systems based on the so-called chemical-nose strategy to transduce the characteristics of microbiota into fluorescence patterns. The fluorescence patterns, generated by twelve block copolymers with aggregation-induced emission (AIE) units, were analyzed using pattern-recognition algorithms, which identified 16 intestinal bacterial strains in a way that correlates with their genome-based taxonomic classification. Importantly, the chemical noses classified artificial models of obesity-associated gut microbiota, and further succeeded in detecting sleep disorder in mice through comparative analysis of normal and abnormal mouse gut microbiota. Our techniques thus allow analyzing complex bacterial samples far more quickly, simply, and inexpensively than common metagenome-based methods, which offers a powerful and complementary tool for the practical analysis of the gut microbiome.

A polymer-based chemical tongue for the non-invasive monitoring of osteogenic stem-cell differentiation by pattern recognition of serum-supplemented spent media.

The development of non-invasive techniques to characterize cultured cells is invaluable not only to ensure the reproducibility of cell research, but also for quality assurance of industrial cell products for purposes such as regenerative medicine. Here, we present a polymer-based 'chemical tongue', i.e., a biosensing technique that mimics the human taste system, that is capable of non-invasively generating fluorescence response patterns that reflect the proteins secreted, and also partially consumed, by cultured cells, even from serum-supplemented media containing abundant interferants. Analysis of the spent media collected during cell culture using our chemical tongue, which consists of cationic polymers of different scaffolds appended with environmentally responsive dansyl fluorophores, led to the successful (i) identification of human-derived cell lines, (ii) monitoring of the differentiation process of stem cells, even at the stage when conventional staining was negative, and (iii) detection of cancer-cell contamination in stem cells. Since the characterization of cultured cells is usually performed via invasive methods that result in cell death, our chemical-tongue approach, which is of high practical utility, will offer a new means of addressing the growing demand for highly controlled cell production in the medical and environmental fields.

Rap1 prevents colitogenic Th17 cell expansion and facilitates Treg cell differentiation and distal TCR signaling.

T-cell-specific Rap1 deletion causes spontaneous colitis in mice. In the present study, we revealed that Rap1 deficiency in T cells impaired the preceding induction of intestinal RORγt+ Treg cells. In the large intestinal lamina propria (LILP) of T-cell-specific Rap1-knockout mice (Rap1KO mice), Th17 cells were found to increase in a microbiota-dependent manner, and the inhibition of IL-17A production prevented the development of colitis. In the LILP of Rap1KO mice, RORγt+ Treg cells were scarcely induced by 4 weeks of age. The expression of CTLA-4 on Rap1-deficient Treg cells was reduced and the expression of CD80 and CD86 on dendritic cells was consequently elevated in Rap1KO mice. When cultured under each polarizing condition, Rap1-deficient naïve CD4+ T cells did not show biased differentiation into Th17 cells; their differentiation into Treg cells as well as Th1 and Th2 cells was lesser than that of wild-type cells. Rap1-deficient naïve CD4+ T cells were found to exhibit the defective nuclear translocation of NFAT and formation of actin foci in response to TCR engagement. These data suggest that Rap1 amplifies the TCR signaling required for Treg-mediated control of intestinal colitogenic Th17 responses.

Brow and Masticatory Muscle Activity Senses Subjective Hedonic Experiences during Food Consumption.

Sensing subjective hedonic or emotional experiences during eating using physiological activity is practically and theoretically important. A recent psychophysiological study has reported that facial electromyography (EMG) measured from the corrugator supercilii muscles was negatively associated with hedonic ratings, including liking, wanting, and valence, during the consumption of solid foods. However, the study protocol prevented participants from natural mastication (crushing of food between the teeth) during physiological data acquisition, which could hide associations between hedonic experiences and masticatory muscle activity during natural eating. We investigated this issue by assessing participants' subjective ratings (liking, wanting, valence, and arousal) and recording physiological measures, including EMG of the corrugator supercilii, zygomatic major, masseter, and suprahyoid muscles while they consumed gel-type solid foods (water-based gellan gum jellies) of diverse flavors. Ratings of liking, wanting, and valence were negatively correlated with corrugator supercilii EMG and positively correlated with masseter and suprahyoid EMG. These findings imply that subjective hedonic experiences during food consumption can be sensed using EMG signals from the brow and masticatory muscles.

Uncharged Components of Single-Stranded DNA Modulate Liquid-Liquid Phase Separation With Cationic Linker Histone H1.

Liquid-liquid phase separation (LLPS) of proteins and DNAs has been recognized as a fundamental mechanism for the formation of intracellular biomolecular condensates. Here, we show the role of the constituent DNA components, i.e., the phosphate groups, deoxyribose sugars, and nucleobases, in LLPS with a polycationic peptide, linker histone H1, a known key regulator of chromatin condensation. A comparison of the phase behavior of mixtures of H1 and single-stranded DNA-based oligomers in which one or more of the constituent moieties of DNA were removed demonstrated that not only the electrostatic interactions between the anionic phosphate groups of the oligomers and the cationic residues of H1, but also the interactions involving nucleobases and deoxyriboses (i) promoted the generation of spherical liquid droplets via LLPS as well as (ii) increased the density of DNA and decreased its fluidity within the droplets under low-salt conditions. Furthermore, we found the formation of non-spherical assemblies with both mobile and immobile fractions at relatively higher concentrations of H1 for all the oligomers. The roles of the DNA components that promote phase separation and modulate droplet characteristics revealed in this study will facilitate our understanding of the formation processes of the various biomolecular condensates containing nucleic acids, such as chromatin organization.

Comparative mapping of crawling-cell morphodynamics in deep learning-based feature space.

Navigation of fast migrating cells such as amoeba Dictyostelium and immune cells are tightly associated with their morphologies that range from steady polarized forms that support high directionality to those more complex and variable when making frequent turns. Model simulations are essential for quantitative understanding of these features and their origins, however systematic comparisons with real data are underdeveloped. Here, by employing deep-learning-based feature extraction combined with phase-field modeling framework, we show that a low dimensional feature space for 2D migrating cell morphologies obtained from the shape stereotype of keratocytes, Dictyostelium and neutrophils can be fully mapped by an interlinked signaling network of cell-polarization and protrusion dynamics. Our analysis links the data-driven shape analysis to the underlying causalities by identifying key parameters critical for migratory morphologies both normal and aberrant under genetic and pharmacological perturbations. The results underscore the importance of deciphering self-organizing states and their interplay when characterizing morphological phenotypes.

Rap1 Is Essential for B-Cell Locomotion, Germinal Center Formation and Normal B-1a Cell Population.

Integrin regulation by Rap1 is indispensable for lymphocyte recirculation. In mice having B-cell-specific Rap1a/b double knockouts (DKO), the number of B cells in lymph nodes decreased to approximately 4% of that of control mice, and B cells were present in the spleen and blood. Upon the immunization with NP-CGG, DKO mice demonstrated the defective GC formation in the spleen, and the reduced NP-specific antibody production. In vitro, Rap1 deficiency impaired the movement of activated B cells along the gradients of chemoattractants known to be critical for their localization in the follicles. Furthermore, B-1a cells were almost completely absent in the peritoneal cavity, spleen and blood of adult DKO mice, and the number of B-cell progenitor/precursor (B-p) were reduced in neonatal and fetal livers. However, DKO B-ps normally proliferated, and differentiated into IgM+ cells in the presence of IL-7. CXCL12-dependent migration of B-ps on the VCAM-1 was severely impaired by Rap1 deficiency. Immunostaining study of fetal livers revealed defects in the co-localization of DKO B-ps and IL-7-producing stromal cells. This study proposes that the profound effects of Rap1-deficiency on humoral responses and B-1a cell generation may be due to or in part caused by impairments of the chemoattractant-dependent positioning and the contact with stromal cells.

Effect of fracture properties of gels on tongue pressure during different phases of squeezing and swallowing.

To provide appropriate foods for elderly people with eating difficulties, it is necessary to take account of the ability of compensatory mastication such as tongue squeezing. However, the biomechanics of tongue squeezing is still unclear. The aim of present study is to investigate the effect of the initial mechanical properties of gels on the change in tongue pressure production during squeezing and swallowing. As test sample, nine kinds of gels with three fracture force and three fracture strain were prepared. Tongue pressure during squeezing and swallowing gels was measured by using an ultra-thin tongue pressure sensor with five measuring points attached on the hard palate in seven healthy participants, and analyzed at four phases; Initial squeeze, Middle squeeze, Last squeeze, and Swallowing. The maximal magnitude of tongue pressure was increased for gels with higher fracture force at most measuring points and was decreased for gels with higher fracture strain at some measuring points on the median line during Initial and Middle squeezing. However, no influence by fracture force and strain was found in magnitude during Last squeezing and Swallowing. The duration of tongue pressure increased for gels with higher force at most measuring points during Middle squeezing, although no influence by strain was found during each phase. The results clearly show how the initial fracture properties of gels influence on tongue pressure production during each phase of food oral processing, which clarified one aspect of squeezing with tongue, as the compensatory mastication.

Microfluidic Sensing System with a Multichannel Surface Plasmon Resonance Chip: Damage-Free Characterization of Cells by Pattern Recognition.

The development of a versatile sensing strategy for the damage-free characterization of cultured cells is of great importance for both fundamental biological research and industrial applications. Here, we present a pattern-recognition-based cell-sensing approach using a multichannel surface plasmon resonance (SPR) chip. The chip, in which five cysteine derivatives with different structures are immobilized on Au films, is capable of generating five unique SPR sensorgrams for the cell-secreted molecules that are contained in cell culture media. An automatic statistical program was built to acquire kinetic parameters from the SPR sensorgrams and to select optimal parameters as "pattern information" for subsequent multivariate analysis. Our system rapidly (∼10 min) provides the complex information by merely depositing a small amount of cell culture media (∼25 µL) onto the chip, and the amount of information obtained is comparable to that furnished by a combination of conventional laborious biochemical assays. This noninvasive pattern-recognition-based cell-sensing approach could potentially be employed as a versatile tool for characterizing cells.

Dissection of α4ß7 integrin regulation by Rap1 using novel conformation-specific monoclonal anti-ß7 antibodies.

Integrin activation is associated with conformational regulation. In this study, we developed a system to evaluate conformational changes in α4ß7 integrin. We first inserted the PA tag into the plexin-semaphorin-integrin (PSI) domain of ß7 chain, which reacted with an anti-PA tag antibody (NZ-1) in an Mn2+-dependent manner. The small GTPase Rap1 deficiency, as well as chemokine stimulation and the introduction of the active form of Rap1, Rap1V12, enhanced the binding of NZ-1 to the PA-tagged mutant integrin, and increased the binding affinity to mucosal addressing cell adhesion molecule-1 (MAdCAM-1). Furthermore, we generated two kinds of hybridomas producing monoclonal antibodies (mAbs) that recognized Mn2+-dependent epitopes of ß7. Both epitopes were exposed to bind to mAbs on the cells by the introduction of Rap1V12. Although one epitope in the PSI domain of ß7 was exposed on Rap1-deficienct cells, the other epitope in the hybrid domain of ß7 was not. These data indicate that the conversion of Rap1-GDP to GTP exerts two distinct effects stepwise on the conformation of α4ß7. The induction of colitis by Rap1-deficient CD4+ effector/memory T cells suggests that the removal of constraining effect by Rap1-GDP on α4ß7 is sufficient for homing of these pathogenic T cells into colon lamina propria (LP).

Phosphatidic acid-dependent localization and basal de-phosphorylation of RA-GEFs regulate lymphocyte trafficking.

BACKGROUND: Lymphocytes circulate between peripheral lymphoid tissues via blood and lymphatic systems, and chemokine-induced migration is important in trafficking lymphocytes to distant sites. The small GTPase Rap1 is important in mediating lymphocyte motility, and Rap1-GEFs are involved in chemokine-mediated Rap1 activation. Here, we describe the roles and mechanisms of Rap1-GEFs in lymphocyte trafficking. RESULTS: In this study, we show that RA-GEF-1 and 2 (also known as Rapgef2 and 6) are key guanine nucleotide exchange factors (GEF) for Rap1 in lymphocyte trafficking. Mice harboring T cell-specific knockouts of Rapgef2/6 demonstrate defective homing and egress of T cells. Sphingosine-1-phosphate (S1P) as well as chemokines activates Rap1 in a RA-GEF-1/2-dependent manner, and their deficiency in T cells impairs Mst1 phosphorylation, cell polarization, and chemotaxis toward S1P gradient. On the other hand, B cell-specific knockouts of Rapgef2/6 impair chemokine-dependent retention of B cells in the bone marrow and passively facilitate egress. Phospholipase D2-dependent production of phosphatidic acid by these chemotactic factors determines spatial distribution of Rap1-GTP subsequent to membrane localization of RA-GEFs and induces the development of front membrane. On the other hand, basal de-phosphorylation of RA-GEFs is necessary for chemotactic factor-dependent increase in GEF activity for Rap1. CONCLUSIONS: We demonstrate here that subcellular distribution and activation of RA-GEFs are key factors for a directional movement of lymphocytes and that phosphatidic acid is critical for membrane translocation of RA-GEFs with chemokine stimulation.

Coordination of tongue pressure production, hyoid movement, and suprahyoid muscle activity during squeezing of gels.

OBJECTIVE: The aim of this study was to evaluate tongue movement and its biomechanical effects during squeezing, one of the oral strategies for processing soft foods, by tongue pressure sensors, videofluorography, and surface electromyography. DESIGN: Fifteen healthy men (mean age, 31.0 ± 4.1 years) without dysphagia were recruited. A 0.1-mm-thick pressure sensor sheet with five measuring points, videofluorography, and surface electromyography were used for synchronous measurements of tongue pressure, hyoid movement, and suprahyoid muscles activity, respectively, while squeezing 5 mL of gels. Amplitude, duration, area, and their sequential order during initial squeezing were analyzed. Differences in hyoid position at the onset, peak, and offset of hyoid movement were also analyzed. RESULTS: At the beginning of initial squeezing, tongue pressure at the middle area of the hard palate, hyoid movement, and suprahyoid muscle activity appeared simultaneously, followed by tongue pressure at the anterior area and then at the posterior area. When the hyoid was in an elevated position, the amplitude of suprahyoid muscle activity and tongue pressure peaked. At the end of initial squeezing, the hyoid position at the offset of hyoid excursion was superior to that at the onset. All evaluation items of tongue pressure, hyoid movement, and suprahyoid muscle activity were modulated according to the texture of gels. CONCLUSIONS: During initial squeezing, tongue pressure, hyoid movement, and suprahyoid muscle activity were coordinated while being modulated by the food texture. At the end of initial squeezing, the hyoid was maintained in an elevated position, which might be beneficial for subsequent squeezing.

Optical Fingerprints of Proteases and Their Inhibited Complexes Provided by Differential Cross-Reactivity of Fluorophore-Labeled Single-Stranded DNA.

The detection of proteases and their complexes with inhibitor proteins is of great importance for diagnosis and medical-treatment applications. In this study, we report a fingerprint-based sensor using an array of single-stranded DNAs (ssDNAs) labeled with environment-responsive 3'-carboxytetramethylrhodamine (TAMRA) for the identification of proteases. Four TAMRA-modified ssDNAs with different sequences solubilized in two different buffer solutions were incorporated in an array that was capable of generating fluorescent fingerprints unique to the proteases through diverse cross-reactive interactions, allowing the discrimination of (i) 8 proteases and (ii) 12 different mixtures of trypsin and its inhibitor protein (α1-antitrypsin) by multivariate analysis. Constructing an array with TAMRA-modified DNA aptamers that bind to different sites of human thrombin provides fluorescence fingerprints that reflect a reduction of the exposed surface area of thrombin upon complexation with antithrombin III, even in the presence of human serum. We finally demonstrate the potential of hybridization with complementary DNAs as an effective means to easily double the fingerprint information for proteases. Our approach based on the cross-reactive capability of ssDNAs enables high-throughput fingerprint-based sensing that can be flexibly designed and easily constructed, not only for the identification of a variety of proteins including proteases but also for the evaluation of their complexation ability.

Compression Test of Soft Food Gels Using a Soft Machine with an Artificial Tongue.

Care food is increasingly required in the advanced-aged society. Mechanical properties of such foods must be modified such that the foods are easily broken by the tongue without chewing. When foods are compressed between the tongue and the hard palate, the tongue deforms considerably, and only soft foods are broken. To simulate tongue compression of soft foods, artificial tongues with stiffness similar to that of the human tongue were created using clear soft materials. Model soft gels were prepared using gellan gums. A piece of gel on an artificial tongue was compressed using a texture analyzer. The deformation profile during the compression test was obtained using a video capture system. The soft machine equipped a soft artificial tongue sometimes fractured food gels unlike hard machine, which always fracture gels. The fracture properties measured using the soft machine were better than those obtained from a conventional test between hard plates to mimic natural oral processing in humans. The fracture force on foods measured using this soft machine may prove useful for the evaluation of food texture that can be mashed using the tongue.

One-Component Array Based on a Dansyl-Modified Polylysine: Generation of Differential Fluorescent Signatures for the Discrimination of Human Cells.

A one-component array-based sensor consisting of a dansyl-modified polylysine (PLL-Dnc) is capable of discriminating the types and compositional ratios of human cells using varying buffer conditions. The PLL-Dnc sensor array, which affords turn-on fluorescence responses against analyte cells that depend on the pH value and the ionic strength, generates differential fluorescence signatures of cells and successfully discriminates eight types of human cell lines (2.0 × 104 cells/mL) with 100% accuracy using multivariate analysis. The array also allows differentiation of the composition of the cell mixtures that contain cells with the same tissue origin but of different subtypes. The good discrimination ability and simple platform of our "one-component"-based array allows an easy and rapid sensing of cells without requiring any information on specific biomarkers.