Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor.

Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions.

Use of a laser displacement sensor with a non-contact electromagnetic vibration device for assessment of simulated periodontal tissue conditions.

A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, 93-99, 2016).

Facial vibrotactile stimulation activates the parasympathetic nervous system: study of salivary secretion, heart rate, pupillary reflex, and functional near-infrared spectroscopy activity.

We previously found that the greatest salivation response in healthy human subjects is produced by facial vibrotactile stimulation of 89 Hz frequency with 1.9 µ m amplitude (89 Hz-S), as reported by Hiraba et al. (2012, 20011, and 2008). We assessed relationships between the blood flow to brain via functional near-infrared spectroscopy (fNIRS) in the frontal cortex and autonomic parameters. We used the heart rate (HRV: heart rate variability analysis in RR intervals), pupil reflex, and salivation as parameters, but the interrelation between each parameter and fNIRS measures remains unknown. We were to investigate the relationship in response to established paradigms using simultaneously each parameter-fNIRS recording in healthy human subjects. Analysis of fNIRS was examined by a comparison of various values between before and after various stimuli (89 Hz-S, 114 Hz-S, listen to classic music, and "Ahh" vocalization). We confirmed that vibrotactile stimulation (89 Hz) of the parotid glands led to the greatest salivation, greatest increase in heart rate variability, and the most constricted pupils. Furthermore, there were almost no detectable differences between fNIRS during 89 Hz-S and fNIRS during listening to classical music of fans. Thus, vibrotactile stimulation of 89 Hz seems to evoke parasympathetic activity.

Detection of orally administered inositol stereoisomers in mouse blood plasma and their effects on translocation of glucose transporter 4 in skeletal muscle cells.

Simple pharmacological studies on inositol stereoisomers are presented in this study. Male ICR mice were orally administered 1 g/kg BW of three inositol stereoisomers, myo-inositol (MI), d-chiro-inositol (DCI), and scyllo-inositol (SI), and blood plasma samples and skeletal muscle fractions were prepared after an hour. The plasma samples were subjected to gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS) analysis. None of the three stereoisomers was seen in untreated samples, but substantial amounts ranging from 2.5 to 6.5 mM were detected only after administration, indicating that orally administered inositol stereoisomers were readily absorbed and their levels elevated in the bloodstream. In addition, plasma of SI-administered animals contained substantial MI, suggesting a possible metabolic conversion of SI to MI. In the skeletal muscle fractions, glucose transporter type 4 (GLUT4) content in the plasma membrane increased, indicating that inositol stereoisomers stimulated GLUT4 translocation.

Cortical control of tongue protrusion and lateral movements in the cat.

Based on area P lesion experiments, we hypothesized that tongue protrusion adapted for licking might be regulated by the lateral wall of the presylvian sulcus (bilateral areas P) of the cerebral cortex (Hiraba H, Sato T, Nakakawa K, Ueda K. 2009. Cortical control of appropriate tongue protrusion during licking in cats--Increase in regional cerebral blood flow (rCBF) of the contralateral area P and in tongue protrusion after the unilateral area P lesion. Somatosens Mot Res 26:82-89). We propose that the right and left lingual muscles are dominated by the right and left hypoglossal nucleus, respectively, and that right and left pyramidal cells projecting to the right and left hypoglossal nucleus, respectively, exist in unilateral area P. These cells project via an inhibitory interneuron relay to the lateral branches toward the left or right pyramidal cells in contralateral area P. In this study, we aimed to demonstrate the existence of inhibitory interneurons using injections of a gamma-aminobutyric acid (GABA) agonist (muscimol), a GABA antagonist (bicuculline), and kainic acid into unilateral area P, followed by examination of tongue protrusion and lateral movements during trained licking and changes in regional cerebral blood flow (rCBF) values in the contralateral area P. We found disordered protrusion toward both sides and a marked decrease in rCBF values in the contralateral area P after bicuculline injection. We also found abnormal tongue protrusion toward the front and a marked increase in rCBF values after muscimol and kainic acid injections. These results suggest that cortical networks between the bilateral areas P are relayed by inhibitory interneurons.

Enhanced production of 2,3-butanediol by engineered Bacillus subtilis.

Production of 2,3-butanediol by Bacillus subtilis takes place in late-log or stationary phase, depending on the expression of bdhA gene encoding acetoin reductase, which converts acetoin to 2,3-butanediol. The present work focuses on the development of a strain of B. subtilis for enhanced production of 2,3-butanediol in early log phase of growth cycle. For this, the bdhA gene was expressed under the control of P( alsSD ) promoter of AlsSD operon for acetoin fermentation which served the substrate for 2,3-butanediol production. Addition of acetic acid in the medium induced the production of 2,3-butanediol by 2-fold. Two-step aerobic-anaerobic fermentation further enhanced 2,3-butanediol production by 4-fold in comparison to the control parental strain. Thus, addition of acetic acid and low dissolved oxygen in the medium are involved in activation of bdhA gene expression from P( alsSD ) promoter in early log phase. Under the conditions tested in this work, the maximum production of 2,3-butanediol, 2.1 g/l from 10 g/l glucose, was obtained at 24 h. Furthermore, under the optimized microaerophilic condition, the production of 2,3-butanediol improved up to 6.1 g/l and overall productivity increased by 6.7-fold to 0.4 g/l h in the engineered strain compared to that in the parental control.

Assessing qualitative changes in simulated periodontal ligament and alveolar bone using a non-contact electromagnetic vibration device.

The objective of this study is to investigate the ability of a non-contact electromagnetic vibration device to assess a simulated periodontal ligament and alveolar bone conditions in experimental tooth models by applying mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity). The non-contact electromagnetic vibration device was made up of three components: vibrator, detector, and analyzer. The experimental tooth model consisted of a cylindrical rod made of polyacetal, a tissue conditioner for soft lining material, and urethane or urethane foam to simulate the tooth, periodontal ligament, and alveolar bone, respectively. The tissue conditioner was prepared by mixing various volumes of liquid with powder. Periotest values (PTVs) were also measured under the same conditions as those of the non-contact electromagnetic vibration device. All of the mechanical parameters derived from the non-contact electromagnetic vibration device significantly decreased as the proportion of liquid increased. Values for the three parameters of the urethane models were significantly larger than those of the urethane foam models. In contrast, PTVs increased significantly as the proportion of liquid increased; however, no significant difference was observed between the urethane and urethane foam models. The non-contact electromagnetic vibration device may be capable of evaluating not only periodontal ligament conditions but also bone quality. Mechanical parameters may be useful for assessing qualitative changes in the periodontal ligament and alveolar bone.

A cell factory of Bacillus subtilis engineered for the simple bioconversion of myo-inositol to scyllo-inositol, a potential therapeutic agent for Alzheimer's disease.

BACKGROUND: A stereoisomer of inositol, scyllo-inositol, is known as a promising therapeutic agent for Alzheimer's disease, since it prevents the accumulation of beta-amyloid deposits, a hallmark of the disease. However, this compound is relatively rare in nature, whereas another stereoisomer of inositol, myo-inositol, is abundantly available. RESULTS: Bacillus subtilis possesses a unique inositol metabolism involving both stereoisomers. We manipulated the inositol metabolism in B. subtilis to permit the possible bioconversion from myo-inositol to scyllo-inositol. Within 48 h of cultivation, the engineered strain was able to convert almost half of 10 g/L myo-inositol to scyllo-inositol that accumulated in the culture medium. CONCLUSIONS: The engineered B. subtilis serves as a prototype of cell factory enabling a novel and inexpensive supply of scyllo-inositol.

Changes in localized arrangement into the hypoglossal nucleus after the neurectomy of unilateral hypoglossal nerve (medial branch) in cats.

We studied changes in orofacial behavior and the arrangement of bilateral hypoglossal nuclei after the neurectomy of the medial branch of the unilateral hypoglossal nerve in cats. After recovery from surgery in a head holder, the animals were acclimated to take and chew fish paste (1.8 g) from a spoon and lick milk from a wetted paintbrush. Next we performed a neurectomy in the unilateral hypoglossal nerve after training. We firstly recorded behavior during the taking of fish paste and licking of milk, and then performed a neurectomy in the unilateral hypoglossal nerve. After nerve cutting, the cats' tongue deviated toward the cut side when they licked food, and bilateral activities of EMGs in the genioglossus muscles became stable in about 1 month. After that, we injected two kinds of fluorescent dye (10% Evans blue, EB, and 3% Fast blue, FB) into the bilateral genioglossus muscles using syringes (0.15 ml in each), respectively. Although each injection of FB and EB into the bilateral genioglossus muscles in normal cats revealed cells positively stained with each dye in the hypoglossal nuclei of each injection site, in cats 1 month after nerve cutting, fluorescent dye was only observed in positive cells in the hypoglossal nucleus of the intact side and the dye injected into the neurectomy side showed a mixture into positive cells of the intact side. The findings suggest that muscles in the neurectomy side may be compensated by regeneration of the peripheral nerves on the intact side.

A no-contact vibration device for measuring implant stability.

OBJECTIVES: Monitoring implant stability is an important factor in determining the long-term success rate of implants. Periotest values and resonance frequency analysis have been widely used for this purpose, but these indicators mainly reflect the mobility and/or stability of implants. Thus, a no-contact electromagnetic vibration device was developed and tested for monitoring both tooth mobility and periodontal tissue conditions. The aim of this study was to evaluate the ability of a no-contact electromagnetic vibration device to measure implant stability under various peri-implant conditions using mechanical parameters. MATERIAL AND METHODS: The device consisted of three components: the vibrator, detector, and analyzer. The mechanical parameters resonant frequency, elastic modulus, and coefficient of viscosity were used to measure simulated atrophic bone defects in periodontal tissues. RESULTS: The resonant frequency and the elastic modulus increased with an increase in supporting bone height. In contrast, the coefficient of viscosity decreased with bone height. Values for the three parameters for the formed urethane models were lower than those for the urethane models. CONCLUSIONS: A no-contact electromagnetic vibration device may be capable of monitoring implant stability, and mechanical parameters may be useful for assessing the condition of periodontal tissues around implants.

Increased secretion of salivary glands produced by facial vibrotactile stimulation.

Patients with low-back pain can be evaluated immediately by means of an electrical tool that produces bony vibration to the lumbar spinal processes (Yrjama M, Vanharanta H. Bony vibrotactile stimulation: A new, non-invasive method for examining intradiscal pain. European Spine Journal 1994;3:233-235). In the rehabilitation of masticatory disturbance and dysphagia, an electric toothbrush is commonly used as an oral motor exercise tool for the facilitation of blood flow and metabolism in the orofacial region in Japanese hospitals. However, subjects receiving vibration in the facial regions reported increased salivary secretion. We attempted to develop an oral motor exercise apparatus modified by a headphone headset that was fixed and could be used for extended periods. The vibration apparatus of the heating conductor is protected by the polyethyle methacrylate (dental mucosa protective material), and electric motors for vibration control of the PWM circuit. We examined the amount of salivation during vibration stimuli on the bilateral masseter muscle belly, using a cotton roll positioned at the opening of the secretory duct for 3 min. Although the quantity of salivation in each subject showed various and large fluctuations in the right and left sides of the parotid and submandibular and sublingual glands, one or more of the salivary glands were effectively stimulated by 89 Hz vibration. The reported apparatus will be useful as an additional method in orofacial rehabilitation.