山田 晃司

Constipation is a prevalent condition that negatively impacts health and quality of life. Inadequate physical activity is a known contributing factor, often associated with reduced gut motility. However, the physiological mechanism linking physical activity and constipation remains unclear. Particularly research on the immediate effects of physical activity on peristalsis is scarce. Therefore, we aimed to elucidate this mechanism by examining the immediate effects of physical activity on gut motility in healthy adults. Twenty-one participants were instructed to walk on a treadmill for 20 min. Bowel sounds were assessed at rest and at intervals up to 15 min after walking. Bowel sounds were used as indirect markers of gut motility. We calculated the sum of the absolute signal amplitudes of bowel sounds, the percentage of bowel sounds duration, and number of discrete bowel sounds, which have been proposed as indices of gut motility. All the indices increased significantly 1-2 min post-exercise compared to resting values. This increase may be attributed to changes in the autonomic nervous system and local reflexes caused by biomechanical oscillations. In addition, gut motility activation might explain the effects of physical activity intervention on constipation and offer insights into its potential role in managing the condition.

OBJECTIVE: To elucidate the relationship between social participation and quality of life (QOL) in patients with traumatic brain injury. METHODS: This study included 128 community-dwelling patients with head injuries (average age: 41.8 years; average time since injury: 3126 days). We employed the Community Integration Questionnaire (CIQ; scoring range 0-29), a disease-specific scale for head injury patients, along with the Quality of Life after Brain Injury (QOLIBRI; scoring range 0-100%). An adjusted nonlinear regression analysis was used to explore the relationships between the CIQ (total score and subscales: home integration, social integration, productivity) and QOLIBRI (total score and subscales). RESULTS: A significant relationship was observed only between the Total CIQ and the Self subscale of the QOLIBRI (p=0.006). The Self subscale score of the QOLIBRI increased with the Total CIQ score up to 15, after which it plateaued. Additionally, a significant positive relationship was found between the Social Integration subscale of the CIQ and the Self subscale of the QOLIBRI (p=0.018). The QOLIBRI Self score increased with the CIQ Social Integration score up to 8, beyond which it remained stable. No associations were found between the CIQ's Home Integration and Productivity subscales and the QOLIBRI scores. CONCLUSION: The findings indicate that for individuals with traumatic brain injury, an increase in social participation, particularly in social integration, correlates with an enhanced sense of self-satisfaction up to a certain point. However, beyond this level, further advances in social participation do not yield additional gains, suggesting that factors other than social participation play a role in enhancing QOL. This underscores the multifaceted nature of QOL in this context.

INTRODUCTION: Exercise has been recommended to suppress or prevent cognitive decline. Aerobic exercise (AE) may suppress cognitive decline via the fibronectin type III domain-containing protein 5 (FNDC5)/irisin/brain-derived neurotrophic factor (BDNF) pathway, and resistance training (RT) has a preventive effect on cognitive decline. However, the underlying mechanism remains unclear. This study verified the differences in the effects of AE and RT in suppressing and preventing cognitive decline based on the FNDC5/irisin/BDNF pathway. METHODS: We divided senescence-accelerated mouse-prone 8 into three groups: control (CON), AE, and RT and evaluated their memory during exercise intervention through a novel object recognition (NOR) task. We quantified FNDC5/irisin, mBDNF, and TrkB in the hippocampus using enzyme-linked immunosorbent assay and FNDC5 in skeletal muscle using Western blotting (WB). RESULTS: Behavioral analysis using NOR showed that values for both AE and RT were significantly greater than those for CON. WB analysis showed that the peripheral FNDC5 expression in the skeletal muscle was increased in AE. The expression levels of FNDC5/irisin and mBDNF in the hippocampus were significantly increased in both AE and RT compared with that in CON but that if TrkB was increased only in AE. CONCLUSION: No significant difference was observed between AE and RT in the inhibitory effect on age-related cognitive decline, and both groups were effective. The FNDC5/Irisin/BDNF pathway, which was the focus of this experiment, may be specific to AE. The mechanism that suppresses cognitive decline may differ depending on the type of exercise.

INTRODUCTION: The decline in spatial working memory is one of the earliest signs of normal brain aging. OBJECTIVE: We developed a novel physical exercise method, termed the "shaking exercise," to slow down this process. METHODS: The experimental protocol included administering the shaking exercise for 8-32 weeks in male senescence-accelerated mouse prone 10 (SAMP-10). They were subjected to the T-maze test, followed by immunohistochemical analysis, to assess the influence of the shaking exercise on the M1 muscarinic acetylcholine receptor (CHRM1) and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) of the dorsal hippocampus and medial prefrontal cortex (dHC-mPFC). RESULTS: The T-maze test demonstrated that the shaking group had less hesitation in the face of selecting direction at week 24. In the immunohistochemical analysis, more CHRM1s were in the CA3 subregion and more AMPARs were in the subiculum. CHRM1s and AMPARs were maintained in the CA1 region and the mPFC. The CHRM1s seem to have a positive effect on the AMPAR in the dentate gyrus (DG) region and the CA3 region. In the CA1 region, CHRM1s were negatively correlated with AMPARs. In addition, high-density neurons were expressed in the shaking group in the upstream DG, the middle part and the distal part of CA3, the distal part of CA1, and the mPFC. CONCLUSIONS: Our results raise the possibility that maintenance of the spatial working memory effect observed with the shaking exercise is driven in part by the uneven affection of CHRM1s and AMPARs in the dHC-mPFC circuit system and significantly maintains the neuronal expression in the dHC-mPFC.

INTRODUCTION: Although exercise can prevent cognitive decline due to aging, few elderly individuals are able to exercise for long. Therefore, an exercise method for older adults that is feasible for a long duration without overexertion is necessary. In this study, we focused on exercise by shaking. This study examined the possibility to prevent the decline in memory through regular and long-term shaking exercise using a senescence-accelerated mouse (SAM) model. Behavioral analysis was conducted, and histological changes in the mouse brain were examined to evaluate whether this stimulation method could become a novel exercise method. MATERIALS AND METHODS: The shaking exercise was applied to SAMP10 mice for 30 min 3 times per week for 25 continuous weeks. Behavioral analysis included a step-through passive avoidance test, whereas the histological analysis involved immunohistochemical staining using the anti-glutamate receptor (α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptors [AMPAR]) antibody in the hippocampus. The number and area of nerve cells in the hippocampal regions were measured and compared between groups. RESULTS: Behavioral analysis revealed that the shaking group retained memory longer than the control group, and memory capacity decline was suppressed. Additionally, histological examination showed that the shaking group had a higher number of AMPAR receptor-positive neurons per area in the hippocampal CA1 and CA3 regions than the control group, suggesting that degeneration and shedding of neurons due to aging was suppressed. DISCUSSION/CONCLUSION: We believe that shaking could become an exercise therapy that can reduce the decline in memory with aging and expect its human application in the future.

Patients with lower limb amputation experience "embodiment" while using a prosthesis, perceiving it as part of their body. Humans control their biological body parts and receive appropriate information by directing attention toward them, which is called body-specific attention. This study investigated whether patients with lower limb amputation similarly direct attention to prosthetic limbs. The participants were 11 patients with lower limb amputation who started training to walk with a prosthesis. Attention to the prosthetic foot was measured longitudinally by a visual detection task. In the initial stage of walking rehabilitation, the index of attention to the prosthetic foot was lower than that to the healthy foot. In the final stage, however, there was no significant difference between the two indexes of attention. Correlation analysis revealed that the longer the duration of prosthetic foot use, the greater the attention directed toward it. These findings indicate that using a prosthesis focuses attention akin to that of an individual's biological limb. Moreover, they expressed that the prosthesis felt like a part of their body when they could walk independently. These findings suggest that the use of prostheses causes integration of visual information and movement about the prosthesis, resulting in its subjective embodiment.

To execute the intended movement, the brain directs attention, called body-specific attention, to the body to obtain information useful for movement. Body-specific attention to the hands has been examined but not to the feet. We aimed to confirm the existence of body-specific attention to the hands and feet, and examine its relation to motor and sensory functions from a behavioral perspective. The study included two groups of 27 right-handed and right-footed healthy adults, respectively. Visual detection tasks were used to measure body-specific attention. We measured reaction times to visual stimuli on or off the self-body and calculated the index of body-specific attention score to subtract the reaction time on self-body from that off one. Participants were classified into low and high attention groups based on each left and right body-specific attention index. For motor functions, Experiment 1 comprised handgrip strength and ball-rotation tasks for the hands, and Experiment 2 comprised toe grip strength involved in postural control for the feet. For sensory functions, the tactile thresholds of the hands and feet were measured. The results showed that, in both hands, the reaction time to visual stimuli on the hand was significantly lesser than that offhand. In the foot, this facilitation effect was observed in the right foot but not the left, which showed the correlation between body-specific attention and the normalized toe gripping force, suggesting that body-specific attention affected postural control. In the hand, the number of rotations of the ball was higher in the high than in the low attention group, regardless of the elaboration exercise difficulty or the left or right hand. However, this relation was not observed in the handgripping task. Thus, body-specific attention to the hand is an important component of elaborate movements. The tactile threshold was higher in the high than in the low attention group, regardless of the side in hand and foot. The results suggested that more body-specific attention is directed to the limbs with lower tactile abilities, supporting the sensory information reaching the brain. Therefore, we suggested that body-specific attention regulates the sensory information to help motor control.

著者らは、骨粗鬆症に伴う骨折の予防を目的に、振動刺激と振盪刺激の2種類の刺激を組み合わせたコンビネーション刺激装置を開発した。今回、骨密度低下モデルマウスを用いて、この新規刺激装置の効果を検討した。8週齢の雌性マウス12匹に対して卵巣摘出により骨密度低下モデルマウスを作製した後、刺激群と非刺激群に分け、刺激群には連続10週間に亘り刺激を行った。類骨量、類骨面、類骨幅、類骨厚、骨石灰化速度、組織を基準とした骨形成速度は、刺激群が非刺激群に比べて有意に高かった。骨梁間隙は、刺激群が非刺激群に比べて低値を示した。また、大腿四頭筋における骨形成タンパク質2、IL-1β、MyoDなどの発現解析においても、刺激群が非刺激群に比べて有意に高い値を示した。本刺激装置は、骨密度低下モデルマウスに対して骨形成を促進させ、骨密度の低下を予防できる可能性が示唆された。

A病院で日常的に患者の生活援助にかかわっている看護師922名を対象に、解剖生理学の知識活用の困難に、看護師の背景による違いがあるかについて質問紙調査を実施した。対象看護師は、臨床経験年数3年以内、4から5年目、6から10年目、11から15年目、16年以上の5群に分けて背景の検討を行った。400名から回答が得られ、391名(男性48名、女性343名)の有効回答を分析対象とした。解剖生理学の知識活用の困難の違いは「臨床経験年数」の差で見られた。「解剖生理学は苦手である」「解剖生理学で活用されている用語そのものが難しい」などの5項目で特に臨床経験年数での違いが見られた。「解剖生理学は苦手である」「解剖生理学で使われている化学式が難しい」「解剖生理学で使われている分子レベルの知識が難しい」の3項目では、臨床経験年数の多い看護師が自分より経験の少ない看護師よりも困難を感じていることが多いという結果が得られた。

In Japan, 13 million people have osteoporosis, including approximately 9 hundred thousand people who are bedridden owing to bone fractures from falls. Preventing osteoporosis is considered to be an important and effective way of preventing fall-related fractures. Thus, we developed a novel method of locomotor stimulation and analyzed its effectiveness in mice. Specifically, we created a double-loading device that combines vibration and shaking stimulation. The device was used to continuously stimulate ovariectomy-induced decreased bone density mouse models 30 minutes daily for 10 weeks. We then collected femur samples, created undecalcified tissue slices, calculated parameters using bone histomorphomtry, and conducted comparative testing. BS/TV (bone surface/tissue volume), N.Oc/ES (osteoclast number/eroded surface), Oc.S/ES (osteoclast osteoid surface/eroded surface), Omt (osteoid maturation time), Tb.N (trabecular number), Mlt (mineralization lag time) < (p < 0.01), N.Ob (osteoblast number), N.Ob/TV (osteoblast number/tissue volume), sLS (single labeled suface), N.Mu.Oc/ES (multinucle osteoclast number/eroded surface), and N.Mo.Oc/ES (mononucle osteoclast number/eroded surface) (p < 0.05) were significantly higher in the stimulation group than in the non-stimulation group. In addition, BS/BV (bone surface/bone volume), Tb.Sp (trabecular separation), MAR (mineral apposition rate), Aj.Ar (adjusted apposition rate) (p < 0.01), ES (eroded surface ), ES/BS (eroded surface/bone surface), and BRs.R (bone resorption rate) (p < 0.05) were significantly lower in the stimulation group than in the non-stimulation group. These results suggest that stimulation activated osteoblasts and osteoclasts, thereby leading to highly active bone remodeling. We anticipate that bone mineralization will subsequently occur, suggesting that this stimulation technique is effective in preventing osteoporosis by alleviating sudden bone density loss.

ヒトは長時間立った状態を維持する際に、無意識に体の重心を左右に移動させて疲労を抑制する。これは穏やかな全身運動を行っている状態であるといえる。振動板の上で静止立位を維持することは、静止した場所に立つよりより効果的な全身運動を誘導すると考えられる。振動刺激が骨密度減少に与える効果について調べた。骨ミネラル密度(BMD)減少モデルマウスに振動刺激を与えると、大腿骨強度の減少が抑制された。骨の部位により抑制の程度に差がみられた。BMD減少抑制効果は骨の形態、組成、物理的分析により確認された。この方法はヒトにおいても有用であることが示唆された。振動刺激による全身運動は高齢者のみでなく若年者に対しても、骨折予防および健康促進における理学療法として有用であると考えられた。

振盪刺激は閉経後に起こる骨密度低下を防止する効果的な物理療法と考えられている。大腿骨を補強する筋群は、振盪刺激により骨に間接的影響を与えている。この刺激は下半身の筋を中心に等尺性運動もしくは等張性運動を強制的に行う。本研究は下半身の運動に重要とされ、またインナーマッスルとしてよく知られている大腰筋について解析を行った。筋の発生や再生および分化に影響を与える特異的なタンパク質の発現量をWestern blot法を用いて組織学的解析と合わせて比較検討を行った。実験は、ICRマウスを使用し、卵巣摘出した群と正常群の2群に分類し、それぞれの群に対して、刺激を行った群と行わない群に区分した(卵巣摘出/振盪：+/+, +/-,-/+,-/-)、計4群に対して実験を行った。振盪刺激を10週間継続した後に大腰筋を採取し、起始側と停止側の２つの領域を解析するため２等分した。組織学的解析は、筋線維横断面をH.E.染色し、筋線維の短径と線維数を計測した。組織学的解析において、振盪刺激による筋線維の肥大は、筋線維短径の計測により停止側で確認された。しかし、筋線維数の変化については顕著な違いは認められなかった。筋の肥大を促進するタンパク質であるgrowth differentiation factor 8 (GDF-8)と発生・分化に関与するmyogenic factor 5 (Myf-5)、myogenic factor 6 (Myf-6)のタンパク質発現量は、刺激を行った群と行わなかった群において行った群の停止側に増加傾向を示した。大腰筋のような二関節筋の働きをする筋において起始・停止部分で筋肥大ならびに発生や分化に部位差の相違が認められた。本研究において大腰筋の停止部で刺激による部位差が顕著であったことから振盪刺激が姿勢安定による転倒予防と下半身、特に大腿部における骨を補強する効果的な物理療法になり得ると考える。