ジョイント アクションチュウ ノ ボウガイ ワ パフォーマンス オ テイカ サセル ガ ソウホテキ チカラ ハッキ オ ソクシン スル

In soccer or basketball, a player often passes a ball to a teammate. This is an example of coordination between individuals with a common goal in a motor task. Such coordination may occur intentionally and has recently been termed “joint action”. In practical events such as ball games, players have to pass a ball to a teammate even if opposing players interrupt the passing of the ball. In our previous studies on joint action we found that the force produced by two people is complementary. The optimal feedback control theory predicts that as the error produced by the participants increases, error compensation also increases. The present study thus tested the hypothesis that an interruption facilitates complementary force production but negatively influences performance during joint action. Twenty−one students performed both control and interruption experiments. In the control experiment, two participants produced a target force such that the sum of the discrete peak forces produced by their right index fingers was 10% of maximum voluntary contraction. In the interruption experiment, two cooperative participants（participants a and b）produced the same target force as the control experiment, and another participant（participant c）interrupted the peak forces produced by participant b. The force produced by the index finger or thumb of participant c decreased or increased the force produced by participant b. Both experiments consisted of eight blocks, with 50 trials in each block. The interruption was constant across blocks. The correlation between the forces produced by two cooperative participants was more negative in the interruption experiment than in the control experiment. The magnitude of the absolute error and standard deviation of force was greater in the interruption experiment than in the control experiment. These new findings indicate that interruption caused performance to deteriorate during joint action, but facilitated complementary force production

カソウ カンキョウ ノ ウデ ノ イチ カンカク ニ アタエル シカク ト コユウ カンカク ノ カソセイ

Visual and proprioceptive signals conflict when looking through a prism or at a mirror. The present study examined the weighting of the vision and proprioception of arm position by ten participants fitted with dual 3D head−mounted displays. A camera was fixed above their right acromion to photograph the extended right arm. The participants fixed their right shoulder joint at 0°, 30°, or 60°in the adducent direction while their right arm was presented on a display as extended horizontally from the trunk for 30 min. To examine the effects of vision on proprioception, participants demonstrated the perceived position of their right shoulder using their left arm. To examine the effects of proprioception on vision, they demonstrated the position of their right arm on a display using their left arm. The perceived arm position more closely approached the fake arm position as the difference between actual and fake arm positions increased. While the arm position is coded by vision more dominantly than by proprioception, the proprioceptive estimates were adapted to match the visual estimates. If the difference between actual and fake arm positions was 90°, the perceived arm position stabilized at a value between the actual and fake positions. Surprisingly, the arm position on the display was very gradually perceived as approaching the actual arm position as time passed. These results indicate visual and proprioceptive adaptation to visual−porprioceptive mismatches of the arm position. The magnitude of the perceptual distortion is larger for proprioception（ 20％）than for vision（under 10％）

カフアツ ニヨル ジョウシ キョケツジ ノ シンタイ イメージ ノ キュウゲキナ ヘンカ

The authors examined effects of the joint position before the ischaemia on alternation of the joint angle of a phantom limb. We further investigated which nerve fiber contributes to the alternation. While we first blocked participants’upper arm with cuff?inflation, we assessed changes in the perceived joint angles as well as in sensory test. In the second block of their upper arm, we further assessed changes in the perceived joint angles when the position of the hand was changed immediately before the inflation. These experiments showed that whereas the proximal and distal interphalangeal, metacarpophalangeal and wrist joints of the phantom limb steeply changed from extended position to flexed position at the start of extended position from 10 to 25 min after the start of the inflation, the four joints changed to the opposite direction at the start of flexed position. These findings revealed that perceived joint angles of a phantom hand were changed by the position of the hand immediately before the inflation. On the other hand, while threshold of von Frey test in the thumb was changed until mean 16 min after the start of the inflation, the touch sensation in the thumb was abolished until mean 19 min. From the results of two experiments, acute perceptual distortions of joint angle thus corresponded with paralysis of the large myelinated diameter nerv

カフアツ ニヨル ジョウシ キョケツジ ノ テ ノ オオキサ ノ キュウゲキナ チカク ヘンカ

The authors examined which nerve fiber contributes to alternation of the magnitude of the phantom hand. While we blocked participants\u27 upper arm with cuff?inflation, we assessed the perceived size of the their hand as well as changes in thermal and touch sensation. Perceived size was estimated by selection of a simple two?demensional outline or template of the hand which best matched its `size\u27. Prior to matching templates of the hand, in addition to the same sensory assessment of tactile sensation with a cotton swab, temperature sensation was tested with warm, cold and heat metal rods applied to the skin surface. Selection of matching templates of the hand showed that perceived area gradually increased and then reached to a 34% increase at 35 min after the inflation. Although heat pain threshold did not change during the inflation, cool threshold steeply decreased from 15 min after the inflation. The touch sensation in thumb was abolished until 20 min after the inflation, in wrist until ２８ min and in the elbow until 32 min. Perceptual distortion of body size was associated with paralysis of both small and large myelinated diameter nerves

シュシ ノ タッピング ノ タイミング ト チカラ ノ セイギョ ニ アタエル カレイ ノ エイキョウ

The authors examined effects of aging on the control of timing and force in the finger tapping taskfor the 250-ms(250-ms task)or 500-ms(500-ms task)target intertap interval and the 2-N target force. Theanalysis showed that 70s and 80s made both anticipatory and delayed responses for both the 250-ms and 500-ms tasks. There were also significant differences among age groups for intertap interval variability, showing that both 70s and 80s were more variable for the interval than 20s. The self-paced(recall)task was further more variable for the interval of the 250-ms task than the stimulus-initiated(practice)task. The anticipatory response and variable interval in the elders appear similar to those which are typically observed in patients with Parkinson\u27s disease and may be associated with a dysfunction of the basal ganglia. On the other hand, whereas 20s and 60s slightly undershot the force target,70s and 80s overshot the target, indicating that it is difficult for the elders to finely control their force to the target force

Essential role of gastric gland mucin in preventing gastric cancer in mice

信州大学博士（医学）・学位論文・平成24年3月31日授与（甲第916号）・唐澤文寿Gastric gland mucin secreted from the lower portion of the gastric mucosa contains unique O-linked oligosaccharides (O-glycans) having terminal alpha 1,4-linked N-acetylglucosamine residues (alpha GlcNAc). Previously, we identified human alpha 1,4-N-acetylglucosaminyltransferase (alpha 4GnT), which is responsible for the O-glycan biosynthesis and characterized alpha GlcNAc function in suppressing Helicobacter pylori in vitro. In the present study, we engineered A4gnt(-/-) mice to better understand its role in vivo. A4gnt(-/-) mice showed complete lack of alpha GlcNAc expression in gastric gland mucin. Surprisingly, all the mutant mice developed gastric adenocarcinoma through a hyperplasia-dysplasia-carcinoma sequence in the absence of H. pylori infection. Microarray and quantitative RT-PCR analysis revealed upregulation of genes encoding inflammatory chemokine ligands, proinflammatory cytokines, and growth factors, such as Ccl2, Il-11, and Hgf in the gastric mucosa of A4gnt(-/-) mice. Further supporting an important role for this O-glycan in cancer progression, we also observed significantly reduced alpha GlcNAc in human gastric adenocarcinoma and adenoma. Our results demonstrate that the absence of alpha GlcNAc triggers gastric tumorigenesis through inflammation-associated pathways in vivo. Thus, alpha GlcNAc-terminated gastric mucin plays dual roles in preventing gastric cancer by inhibiting H. pylori infection and also suppressing tumor-promoting inflammation.ArticleJOURNAL OF CLINICAL INVESTIGATION. 122(3):923-934 (2012)journal articl

Nod1 acts as an intracellular receptor to stimulate chemokine production and neutrophil recruitment in vivo

Nod1 is a member of family of intracellular proteins that mediate host recognition of bacterial peptidoglycan. To characterize immune responses mediated by Nod1, synthetic ligand compounds possessing enhanced ability to stimulate Nod1 were developed to study the function of Nod1. Stimulation of epithelial cells with Nod1 stimulatory molecules induced chemokines and other proinflammatory molecules that are important for innate immune responses and recruitment of acute inflammatory cells. Administration of Nod1 ligands into mice induced chemokines and recruitment of acute inflammatory cells, an activity that was abolished in Nod1-null mice. Microarray analysis revealed that Nod1 stimulation induces a restricted number of genes in intestinal epithelial cells compared with that induced by tumor necrosis factor (TNF) α. Nod1 stimulation did not induce TNFα, interleukin 12, and interferon γ, suggesting that the primary role of Nod1 is to induce the recruitment of immune cells. These results indicate that Nod1 functions as a pathogen recognition molecule to induce expression of molecules involved in the early stages of the innate immune response

カフアツ ニヨル ジョウシ キョケツジ ノ ヒジ ト テクビ ノ シセイ ノ チカク ヘンカ

Our previous study showed dynamic changes in the perceived posture of the hand when inputs from large−diameter sensory nerve fibres of the hand were declined and lost. The present study further exhibited that the perceived position at the elbow changed systematically even when the sensory inputs from the arm were partially blocked. Ten healthy participants showed perceived postures of their right elbows and wrists with an ischemic block of the right upper arm using the left arms and hands. When the right arm and hand were fully extended before and during the block, the final perceived joints at the wrist and elbow were flexed in all participants, and vice versa. While there was no significant difference between joints for the magnitude of the perceived changes in full extension, the magnitude of the perceived changes at the elbow reached about 60°. In full flexion, however, the magnitude at the elbow was less than that at the wrist, indicating that the peripheral nerves at the elbow was less blocked than those at the wrist at the end of the block. Because the start of these changes occurred as the sensory inputs were declining, the changes depended on fading somatosensory signals from strongly stretching muscle and skin during the anesthesia