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Objective: The stabilization of both the horizontal (H) and vertical (V) eye movements during voluntary fixation is believed to depend upon the visual feedback system in the upright position. However, ocular stability in the tilted position has been less well investigated. Therefore, in the present study, we examined the gaze stability of healthy human subjects in the three dimensions in the tilted position using a video image analysis system (VIAS).Methods: In 10 healthy human subjects, the eye movements were recorded after fixating the eye on a target in an upright position and also in the tilted position. The standard deviations of the eye movements in the three dimensions were calculated to evaluate the stability of the movements.Results: In the tilted position, there were no significant changes in the horizontal and vertical eye movements as compared those in the upright position. However, the standard deviation of the torsional (T) segment was significantly larger in the tilted position, compared to that in the upright position.Conclusion: From these results, we speculate that, a combination of otolith and somatosensory inputs play a major role in maintaining the stability of eye movements. [ABSTRACT FROM AUTHOR]

Introduction Various stimuli to the dentin surface elicit dentinal pain by inducing dentinal fluid movement causing cellular deformation in odontoblasts. Although odontoblasts detect deformation by the activation of mechanosensitive ionic channels, it is still unclear whether odontoblasts are capable of establishing neurotransmission with myelinated A delta (Aδ) neurons. Additionally, it is still unclear whether these neurons evoke action potentials by neurotransmitters from odontoblasts to mediate sensory transduction in dentin. Thus, we investigated evoked inward currents and evoked action potentials form trigeminal ganglion (TG) neurons after odontoblast mechanical stimulation. Methods We used patch clamp recordings to identify electrophysiological properties and record evoked responses in TG neurons. Results We classified TG cells into small-sized and medium-sized neurons. In both types of neurons, we observed voltage-dependent inward currents. The currents from medium-sized neurons showed fast inactivation kinetics. When mechanical stimuli were applied to odontoblasts, evoked inward currents were recorded from medium-sized neurons. Antagonists for the ionotropic adenosine triphosphate receptor (P2X 3 ), transient receptor potential channel subfamilies, and Piezo1 channel significantly inhibited these inward currents. Mechanical stimulation to odontoblasts also generated action potentials in the isolectin B 4 –negative medium-sized neurons. Action potentials in these isolectin B 4 –negative medium-sized neurons showed a short duration. Overall, electrophysiological properties of neurons indicate that the TG neurons with recorded evoked responses after odontoblast mechanical stimulation were myelinated Aδ neurons. Conclusions Odontoblasts established neurotransmission with myelinated Aδ neurons via P2X 3 receptor activation. The results also indicated that mechanosensitive TRP/Piezo1 channels were functionally expressed in odontoblasts. The activation of P2X 3 receptors induced an action potential in the Aδ neurons, underlying a sensory generation mechanism of dentinal pain. [ABSTRACT FROM AUTHOR]

Purinergic receptors play key signaling roles in neuropathic pain in the orofacial region, which is innervated by trigeminal ganglion (TG) neurons. The neuropathology of purinergic P2Y 12 receptors is well characterized in glia; however, their physiological role in TG neurons remains to be fully elucidated. The present study investigated the expression and function of P2Y 12 receptors in rat TG neurons. P2Y 12 receptor immunoreactivity was intense in the soma, dendrites, and axons, and colocalized with a pan-neuronal marker, neurofilament H, isolectin B4, and substance P. In the presence of extracellular Ca 2+ , 2-methylthio-ADP (an agonist of P2Y 1, 12, 13 receptors) transiently increased intracellular free Ca 2+ concentrations ([Ca 2+ ] i ), an effect that was abolished by P2Y 12 receptor antagonists. In the absence of extracellular Ca 2+ , ryanodine receptor/channel inhibitors diminished the 2-methylthio-ADP-induced increases in [Ca 2+ ] i . A sarcoplasmic reticulum Ca 2+ -ATPase (SERCA) inhibitor gradually increased [Ca 2+ ] i , and after a plateau, application of 2-MeS-ADP induced a rapid and transient, but additive increase in [Ca 2+ ] i . An adenylate cyclase inhibitor transiently increased [Ca 2+ ] i , while a phosphodiesterase inhibitor prevented the 2-methylthio-ADP-induced increase in [Ca 2+ ] i . Our study shows that P2Y 12 receptors are expressed in TG neurons, and act via a cAMP-dependent pathway to release intracellular Ca 2+ from ryanodine-sensitive Ca 2+ stores. [ABSTRACT FROM AUTHOR]

Abstract: Unusual expansion of trinucleotide repeats has been identified as a common mechanism of hereditary neurodegenerative diseases. Although the actual mechanism of repeat expansion remains uncertain, trinucleotide repeat instability may be related to the increased stability of an alternative DNA hairpin structure formed in the repeat sequences. Here we report that a synthetic ligand naphthyridine carbamate dimer (NCD) selectively bound to and stabilized an intra-stranded hairpin structure in CGG repeat sequences. The NCD–CGG hairpin complex was a stable structure that efficiently interfered with DNA replication by Taq DNA polymerase. Considering the sequence preference of NCD, the use of NCD would be valuable to investigate the genetic instabilities of CGG/CCG repeat sequences in human genomes. [Copyright &y& Elsevier]

Abstract: Objective: Based on the hypothesis that the origin of nystagmus is from the posterior canal (PC), the nystagmus in the head hanging and sitting position should be mirror images. To clarify the anatomical origin of positioning nystagmus in BPPV patients, we analyzed the positioning nystagmus of benign paroxysmal positioning vertigo (BPPV) patients three-dimensionally. Methods: Twenty-six patients with BPPV participated in this study. The positioning nystagmus was recorded in complete darkness from the patient''s left eye by means of an infrared CCD camera. We performed three-dimensional analysis of nystagmus using video image analysis system (VIAS). Subsequently, the rotation axis of the 3D eye movements of the positioning nystagmus was calculated. Results: Among the 26 patients tested, 20 patients demonstrated the axes of nystagmus in good or relatively good alignment to the PC axis. However, in 11 of these 20 patients there was poor alignment of the axis of nystagmus in the sitting position to the PC axis. In addition, six patients showed axes of nystagmus with poor alignment to the PC in the head hanging position. Among them, two patients exhibited axes of nystagmus in good alignment with the anterior canal, in spite of diagnosis of these patients as PC BPPV by experienced examiner based on the positioning nystagmus test. Conclusion: These results demonstrated that only one-third of patients who were diagnosed as BPPV, could be diagnosed as true BPPV which originates from a PC pathology. Besides the possibility that the pathology may originate from the AC, it is still unclear which part of the inner ear may be the candidate site of origin of the pathology of BPPV in the other 15 patients. [Copyright &y& Elsevier]

For the treatment of nasal and nostril stenosis caused by facial burn, it is necessary to perform rhinoplasty and nasal vestibuloplasty using various flaps, perform cicatrectomy of the nostrils with a rhinosurgical procedure, and prevent restenosis of the nostrils and nasal cavity for a certain period by methods such as placement of a nasal retainer or transnasal airway and gauze packing of the nasal cavity. With all methods, postoperative placement of a retainer or nasal treatment is necessary for the prevention of postoperative restenosis, and the patient's cooperation is essential. In a patient who did not cooperate in postoperative treatments due to autism and had recurrences of nasal and nostril stenosis after conventional surgical treatments, adequate patency of the nasal cavity and nostrils could be maintained with minimal postoperative treatment by placing a self-expandable metallic esophageal stent. [ABSTRACT FROM AUTHOR]

Abstract: In order to record and analyze the rapid eye movement non-invasively in human subjects, a four times high-speed video camera (4TC) with a new computer software was developed and utilized. Nine healthy volunteers and four patients with vestibular dysfunction participated in this study. Caloric stimulation was applied to the healthy subjects and the eye movements were recorded using a standard camera (SC) and a 4TC. In four patients, the positional and/or positioning nystagmus was recorded using SC and 4TC. Analysis of the eye speed of the quick phase of nystagmus was performed manually from the print out of the chart. The quick phase of the caloric nystagmus was adequately analyzed from the data using 4TC. However, using SC the sampling rate was not sufficiently enough for this purpose, as prospected. The adaptability of the 4TC in clinical examination is exactly similar to that of SC, because of the size and weight of the camera. Although the time taken to analyze eye movements using 4TC is about four times longer than that using SC, this system is quite useful and adequate for analyzing the quick eye movements in vestibular nystagmus, in an out-patient clinic set up. [Copyright &y& Elsevier]

Abstract: Objectives:: Presently, the neurotological tests, using visual stimulation, such as optokinetic nystagmus test (OKN), eye-tracking test (ETT) is being widely used for the diagnosis of vertigo or disequilibrium. The problems of these tests are the large size of the visual stimulator and therefore a wide space requirement. Even if a small apparatus is developed, the apparatus itself would be very expensive. In this study, we developed a small visual stimulation test system comprising the virtual visor, which receives an image for visual stimulation from an on-line computer. Methods:: Using smooth pursuit and optokinetic stimulation onto a virtual visor we assessed the ENG recording in 20 normal subjects. Result:: We found the 30°/s OKN, horizontal eye tracking were adequately stimulated by this technique with reliable results. Conclusion:: This new method of smooth pursuit and optokinetic stimulating by a virtual visor is capable of producing reliable results and may be used in the clinical laboratory of vertigo. However, this stimulator also has some limitations, mainly because of the visual angle of the virtual visor stimulator. [Copyright &y& Elsevier]

• Swallowing timings were evaluated by two barometers in oral cavity and oropharynx. • Anterior and posterior intrinsic tongue EMGs were also recorded. • Timings of nasopharyngeal closure could be measured by the sensor in oral cavity. • Durations of oral and pharyngeal stages of swallowing were measured as 0.4 and 0.6 sec. • The tongue begins the activity for swallowing before nasopharyngeal closure. : The exact timings associated with swallowing are difficult to measure with the currently available methods. In this study, we aimed to elucidate the timings of action of the swallowing organs in the oral and pharyngeal stages of swallowing by recording the barometric pressure (BP) and tongue muscle activities. : Dry and water swallows were studied in 10 adults using electromyography and small barometers. BPs were recorded during swallowing in the oral cavity (BP-o) and pharynx (BP-p), associated with muscle activities of the anterior (TA) and posterior (TP) parts of the tongue and of the suprahyoid (SHy) muscle. To analyze the temporal pattern of each activity, times of onset, cessation, and peak were measured. : Two characteristic waveforms were obtained. BP-o peaked immediately after onset and decreased to atmospheric pressure following a short plateau. However, BP-p gradually increased, reached a peak, and returned to the atmospheric pressure immediately before the end of BP-o. Since pressure increments indicated that the sensor was compressed in a closed space, onset and cessation of BP-p could correspond to the duration of nasopharyngeal closure. The onset of BP-p and the peak time of BP-o occurred in close succession. Thus, nasopharyngeal closure could be evaluated from BP-o. The sensor and EMG measured durations of oral and pharyngeal stages as 0.4 and 0.6 sec, respectively. TA activation began earlier than the TP. TA and TP peaks appeared before the BP-o peak, suggesting that the tongue begins the activity for swallowing before nasopharyngeal closure. : This study revealed movements of swallowing organs in the two stages with high temporal resolution. BP-o detected the duration of nasopharyngeal closure. [ABSTRACT FROM AUTHOR]