173 research outputs found
Postural Stability Changes during Large Vertical Diplopia Induced by Prism Wear in Normal Subjects
To test the effect of double vision on postural stability, we measured postural stability by electric stabilometry before prism-wearing and immediately, 15, 30, and 60min after continuous prism-wearing with 6 prism diopters in total (a 3-prism-diopter prism placed with the base up in front of one eye and with the base down in front of the other eye) in 20 normal adult individuals with their eyes open or closed. Changes in stabilometric parameters in the time course of 60min were analyzed statistically by repeated-measure analysis of variance. When subjectsセ eyes were closed, the total linear length (cm) and the unit-time length (cm/sec) of the sway path were significantly shortened during the 60-minute prism-wearing (p<0.05). No significant change was noted in any stabilometric parameters obtained with the eyes open during the time course. In conclusion, postural stability did not change with the eyes open in the condition of large vertical diplopia, induced by prism-wearing for 60min, while the stability became better when measured with the eyes closed. A postural control mechanism other than that derived from visual input might be reinforced under abnormal visual input such as non-fusionable diplopia
Oral lichenoid drug reaction with autoantibodies in peripheral blood: Case report
AbstractA 51-year-old man complained of oral roughness and pain. At the age of 49 years, he was admitted for 8 months for bipolar emotional disorder. Oral administration of lithium carbonate was started. Extensive, hemorrhagic, erythema-mixed white lace-like patches were noted on the lip, buccal mucosae, and lingual margins. On biopsy, all lesions were consistent with oral lichen planus. A drug lymphocyte stimulation test showed a positive reaction to lithium carbonate. Blood examination revealed marked increases in the peripheral blood levels of antinuclear antibodies. To relieve the symptoms, the systemic administration of prednisolone was performed while continuing the lithium carbonate
Minimum oxygen cost of human walking with geometrically similar leg movements
The mechanism by which the expenditure of oxygen to walk per unit distance at an intermediate speed is minimized, by definition optimal walking, was investigated to characterize optimal walking in humans with variations in individual walking speeds. Oxygen uptake and step rate(SR)were measured among 7 young male subjects walking at an increasing speed from 16.7 to 131.7 m min−1 with 5 m min−1 increments every 1 min on a level treadmill. Measurements of leg length(L)were also made and step length(SL)was calculated by dividing walking speed by SR. The hip joint angle(θ)was calculated as a function of both L and SL such that θ=2sin−[1 SL(/ 2L)] deduced from a mathematical geometrically similar model of pendulum−like legs. The minimum oxygen cost to walk per unit distance for each subject was observed over a wide range of speeds from 60 to 100 m min−1.However, the oxygen cost of walking for all the subjects was minimized during a step cycle through a hip−joint angle of about 46 deg in the astride position, regardless of L. The stifflegged model demonstrated that the pathway of the trunk during optimal walking with a swing leg angle of 46 deg was approximately maintained at an even level by the counteracting effects of the leg decline and the heel rise. These results suggest that the minimum oxygen cost of transport during optimal walking was achieved by the mechanism underlying the maximum interchange between the gravitational−potential and kinetic energy for the body with an even level of the trunk that reduces extra muscular work needed against internal and external resistance, as well as against gravit
Cevimeline enhances the excitability of rat superior salivatory neurons
Cevimeline, a therapeutic drug for xerostomia, is an agonist of muscarinic acetylcholine receptors (mAChRs), and directly stimulates the peripheral mAChRs of the salivary glands. Since cevimeline is distributed in the brain after its oral administration, it is possible that it affects the central nervous system. However, it is unknown how cevimeline affects the superior salivatory (SS) neurons, which control submandibular salivation. In the present study, we examined the effects of cevimeline on the SS neurons using the whole-cell patch-clamp technique in brain slices. In Wistar rats (6-10 days), the SS neurons were retrogradely labeled by Texas Red applied to the chorda-lingual nerve. Two days after injection, whole-cell recordings were obtained from the labeled cells, and miniature excitatory postsynaptic currents (mEPSCs) were examined. Cevimeline induced the inward currents dose-dependently and increased the frequency of mEPSCs. Therefore, it is suggested that cevimeline enhances the excitability via post- and presynaptic muscarinic receptors in the rat SS neurons. In conclusion, cevimeline may enhance the excitability of the SS neurons
Pcdhβ deficiency affects hippocampal CA1 ensemble activity and contextual fear discrimination
Clustered protocadherins (Pcdhs), a large group of adhesion molecules, are important for axonal projections and dendritic spread, but little is known about how they influence neuronal activity. The Pcdhβ cluster is strongly expressed in the hippocampus, and in vivo Ca2+ imaging in Pcdhβ-deficient mice revealed altered activity of neuronal ensembles but not of individual cells in this region in freely moving animals. Specifically, Pcdhβ deficiency increased the number of large-size neuronal ensembles and the proportion of cells shared between ensembles. Furthermore, Pcdhβ-deficient mice exhibited reduced repetitive neuronal population activity during exploration of a novel context and were less able to discriminate contexts in a contextual fear conditioning paradigm. These results suggest that one function of Pcdhβs is to modulate neural ensemble activity in the hippocampus to promote context discrimination
Disconnectivity between Dorsal Raphe Nucleus and Posterior Cingulate Cortex in Later Life Depression
The dorsal raphe nucleus (DRN) has been repeatedly implicated as having a significant relationship with depression, along with its serotoninergic innervation. However, functional connectivity of the DRN in depression is not well understood. The current study aimed to isolate functional connectivity of the DRN distinct in later life depression (LLD) compared to a healthy age-matched population. Resting state functional magnetic resonance imaging (rsfMRI) data from 95 participants (33 LLD and 62 healthy) were collected to examine functional connectivity from the DRN to the whole brain in voxel-wise fashion. The posterior cingulate cortex (PCC) bilaterally showed significantly smaller connectivity in the LLD group than the control group. The DRN to PCC connectivity did not show any association with the depressive status. The findings implicate that the LLD involves disruption of serotoninergic input to the PCC, which has been suggested to be a part of the reduced default mode network in depression
New vasorelaxant indole alkaloids, villocarines A-D from Uncaria villosa.
Villocarines A–D (1–4), four new indole alkaloids have been isolated from the leaves of Uncaria villosa (Rubiaceae) and their structures were elucidated by 2D NMR methods and chemical correlations. Villocarine A (1) showed vasorelaxation activity against rat aortic ring and showed inhibition effect on vasocontraction of depolarized aorta with high concentration potassium, and also inhibition effect on phenylephrine (PE)-induced contraction in the presence of nicardipine in a Ca2+ concentration-dependent manner. The vasorelaxant effect by 1 might be attributed mainly to inhibition of calcium influx from extracellular space through voltage-dependent calcium channels (VDC) and/or receptor-operated Ca2+-channels (ROC), and also partly mediated through the increased release of NO from endothelial cells and opening of voltage-gated K+-channels
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