Body representation underlies response of proprioceptive acuity to repetitive peripheral magnetic stimulation

Proprioceptive acuity is of great significance in basic research exploring a possible neural mechanism of fine motor control and in neurorehabilitation practice promoting motor function recovery of limb-disabled people. Moreover, body representation relies on the integration of multiple somatic sensations, including proprioception that is mainly generated in muscles and tendons of human joints. This study aimed to examine two hypotheses: First, different extension positions of wrist joint have different proprioceptive acuities, which might indicate different body representations of wrist joint in the brain. Second, repetitive peripheral magnetic stimulation (rPMS) applied peripherally to the forearm radial nerve and extensors could change proprioceptive acuity at the wrist joint. Thirty-five healthy participants were recruited then randomly divided into the real stimulation group (n = 15) and the sham stimulation group (n = 20). The participants’ non-dominant side wrist joint position sense was tested at six extension positions within the physiological joint motion range (i.e., 10°, 20°, 30°, 40°, 50°, 60°) both before stimulation and after stimulation. Results showed that proprioceptive bias (arithmetic difference of target position and replicated position) among six extension positions could be divided into lower-extension position (i.e., 10°, 20°, 30°) and higher-extension position (i.e., 40°, 50°, 60°). One session rPMS could influence proprioceptive bias in lower-extension position but not in higher-extension position. However, proprioceptive precision (standard deviation within lower-extension position and higher-extension position) was not influenced. To conclude, proprioceptive bias may vary between different wrist extension positions due to different hand postures being related to changes in body representation, and different functions relating to proprioceptive bias and proprioceptive precision may underlie two aspects of body representation.

Body-Specific Attention to the Hands and Feet in Healthy Adults

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.

Mental Health and Physical Activity among Children and Adolescents during the COVID-19 Pandemic

Coronavirus disease 2019 (COVID-19) is causing disruptions in the global social system. Japanese children and adolescents have had their schools closed, government-mandated activity restrictions imposed, and interactions outside the home reduced. These restrictions can have a considerable psychological impact on children and adolescents. This review aims to describe the impacts of COVID-19 pandemic on physical activity and psychological status of this population. The review was conducted by searching PubMed for information on the impact of COVID-19-related activity restrictions on children and adolescents. The search identified 11 articles, three of which contained data on anxiety and psychological problems due to physical inactivity. Next, a PubMed search was conducted about physical activity and psychological status in children and adolescents under psychological stress. The search identified 368 articles, 28 of which were included in the review. For children, data that revealed a correlation between physical activity and psychological health and sedentary time leading to mood disorders were included. For adolescents, there were nine studies that reported a correlation between physical activity and psychological health and four studies that reported no correlation between physical activity and psychological health. Of the studies that reported a correlation, seven reported that physical activity improves psychological health. The impact of psychologically stressful situations such as COVID-19 on children and adolescents has been experienced worldwide. Physical activity has been correlated with psychological health, and it may improve psychological status; physical activity should be recommended to better support the psychological health of children and adolescents under the influence of COVID-19.

Respiratory Muscle Weakness as a Risk Factor for Pneumonia in Older People

INTRODUCTION

The respiratory muscle strength regulates the effectiveness of coughing, which clears the airways and protects people from pneumonia. Sarcopenia is an aging-related loss of muscle mass and function, the worsening of which is associated with malnutrition. The loss of respiratory and swallowing muscle strength occurs with aging, but its effect on pneumonia is unclear. This study aimed to determine the risks of respiratory muscle weakness on the onset and relapse of pneumonia in older people in conjunction with other muscle-related factors such as malnutrition.

METHODS

We conducted a longitudinal study with 47 pneumonia inpatients and 35 non-pneumonia controls aged 70 years and older. We evaluated the strength of respiratory and swallowing muscles, muscle mass, and malnutrition (assessed by serum albumin levels and somatic fat) during admission and confirmed pneumonia relapse within 6 months. The maximal inspiratory and expiratory pressures determined the respiratory muscle strength. Swallowing muscle strength was evaluated by tongue pressure. Bioelectrical impedance analysis was used to evaluate the muscle and fat mass.

RESULTS

The respiratory muscle strength, body trunk muscle mass, serum albumin level, somatic fat mass, and tongue pressure were significantly lower in pneumonia patients than in controls. Risk factors for the onset of pneumonia were low inspiratory respiratory muscle strength (odds ratio [OR], 6.85; 95% confidence interval [CI], 1.56-30.11), low body trunk muscle mass divided by height2 (OR, 6.86; 95% CI, 1.49-31.65), and low serum albumin level (OR, 5.46; 95% CI, 1.51-19.79). For the relapse of pneumonia, low somatic fat mass divided by height2 was a risk factor (OR, 20.10; 95% CI, 2.10-192.42).

DISCUSSION/CONCLUSIONS

Respiratory muscle weakness, lower body trunk muscle mass, and malnutrition were risk factors for the onset of pneumonia in older people. For the relapse of pneumonia, malnutrition was a risk factor.

Modulation of Interhemispheric Inhibition between Primary Motor Cortices Induced by Manual Motor Imitation: A Transcranial Magnetic Stimulation Study

Imitation has been proven effective in motor development and neurorehabilitation. However, the relationship between imitation and interhemispheric inhibition (IHI) remains unclear. Transcranial magnetic stimulation (TMS) can be used to investigate IHI. In this study, the modification effects of IHI resulting from mirror neuron system (MNS) activation during different imitations are addressed. We measured IHI between homologous primary motor cortex (M1) by analyzing the ipsilateral silent period (iSP) evoked by single-pulse focal TMS during imitation and analyzed the respective IHI modulation during and after different patterns of imitation. Our main results showed that throughout anatomical imitation, significant time-course changes of iSP duration through the experiment were observed in both directions. iSP duration declined from the pre-imitation time point to the post-imitation time point and did not return to baseline after 30 min rest. We also observed significant iSP reduction from the right hemisphere to the left hemisphere during anatomical and specular imitation, compared with non-imitative movement. Our findings indicate that using anatomical imitation in action observation and execution therapy promotes functional recovery in neurorehabilitation by regulating IHI.

Spino-pelvic- lower extremity balance during walking in elderly patients with spinal kyphosis

BACK GROUND

Patients with spinal kyphosis were radiographically evaluated while standing. However, the spino-pelvic alignment during walking is different. This study examined the spino-pelvic-lower extremity alignment during walking by a three-dimensional (3D) motion analysis.

METHODS

Twenty-six patients with a sagittal vertical axis of ≥4 cm (male: female, 5:21; average age, 66 years) were evaluated. Using a 3D motion capture system, the trunk and pelvic anterior inclination angles, hip and knee joint angles were measured during a 3-min walk. The correlation coefficient between the change of the trunk anterior inclination angle and each parameter at the beginning of walking was calculated, and those parameters were compared with radiographic measurements.

RESULTS

The patients were divided into two groups according to the change of the trunk anterior inclination angle: the large change group included 14 patients with an increase of ≥5° between the beginning and end of the 3-min walk; the small change group included 12 patients with an increase of <5°. The pelvic anterior inclination angle showed a significant difference between the two groups at the first gait cycles. The pelvic anterior inclination angle and the hip joint angle in the large change group showed a significant difference between the first and last cycles. The correlation coefficient revealed a significant association between the change in the trunk anterior inclination angle and the pelvic anterior inclination angle at the beginning of walking. There were no significant differences between the two groups in any radiographic spino-pelvic parameters.

CONCLUSIONS

There were two types of patients with spinal kyphosis: patients with a small pelvic anterior inclination angle at the beginning of walking showed slight progression in their trunk anterior inclination, whereas those with a large pelvic angle showed a large degree of progression in their pelvic and trunk inclination during walking.

Prediction of life-space mobility in patients with stroke 2 months after discharge from rehabilitation: a retrospective cohort study

Purpose: To determine the predictors of life-space mobility among patients with stroke 2 months after discharge from a post-acute rehabilitation unit.Materials and methods: The study population was 1023 patients discharged from a post-acute rehabilitation unit in Japan. We assessed the relationships between life-space mobility 2 months after discharge and age, sex, length of hospital stay, cognition and motor function (Functional Independence Measure), severity of hemiparesis, falls efficacy, physical function (Timed Up and Go (TUG) test), walking distance ability and social support from family and friends.Results: Bivariate and multiple regression analyses showed that life-space mobility was predicted by sex, age, cognitive score at discharge, TUG score <15 s, length of hospital stay and falls efficacy at discharge. Taken together, these factors accounted for 54% of the variability in life-space mobility. A predictive formula was determined for clinical use.Conclusions: The predictive formula provides an objective measure of life-space mobility for stroke patients after discharge. The clinical application of this formula could help health care professionals working in stroke rehabilitation to prepare patients for discharge and to set concrete goals for in-hospital rehabilitation to improve life-space mobility after discharge.Implications for rehabilitationAccurate prediction of the prognosis for life-space mobility 2 months after discharge is useful in establishing clear goals for community-based rehabilitation.Long-term life-space mobility in the community is not only affected by physical function, but also by sex, age, cognitive ability and falls efficacy at discharge.Life-space mobility in female patients is affected by factors reflecting physical function, whereas life-space mobility in male patients is affected by both physical and cognitive function.Prediction of life-space mobility after stroke is important to determine unique mobility goals in rehabilitation and the required use of adaptive equipment after discharge (e.g., returning to work, engaging in a hobby or travelling beyond the immediate neighbourhood).

Angular acceleration and angular jerk of elbow extension-flexion movement as parameters for discriminating a sequential transform of spontaneous movements in early infants

Objective: We assessed the root mean square (RMS) of angular acceleration and the RMS of an angular jerk as expressions of the transformation of spontaneous movements in early infancy. Methods: During 36-56 weeks post-menstrual age (PMA), 15 premature infants (6 male, 9 female; 36 weeks PMA>) were measured every 4 weeks. A three-dimensional motion analyzer (Fastrak system; Polhemus Inc.) was used to measure spontaneous movements of the upper right limb in the supine infants. Upper limb position data were used to calculate the RMS of angular acceleration and the RMS of angular jerk at the elbow. The calculated data were classified into three terms: 36th and 40th week PMA (termⅠ), the 44th and 48th week PMA (termⅡ), and the 52nd and 56th week PMA (termⅢ). The typical value was the mean value for each term. Results: The RMS of angular acceleration in termⅡ was significantly less than that of termⅠ (p<0.05). The RMS values of angular jerk in termⅡ and termⅢ were significantly less than that of termⅠ (p<0.05). Conclusion: The RMS of angular acceleration and the RMS of the angular jerk are useful for expressing changes in the strength of spontaneous movements of elbow extension-flexion movements.

Rhythm of daily living and detection of atypical days for elderly people living alone as determined with a monitoring system

We have developed a system for monitoring the health of elderly people living at home. Infrared and other sensor outputs are collected using a monitoring program installed on a personal computer (PC) in the home at a sampling rate of 1 Hz. Once each day, the data are transferred to a server through the Internet using a cable television (TV) connection. An elderly subject was monitored for a 12-day baseline period and completed a daily questionnaire about her activities. This enabled us to identify the rhythm of daily living (sleeping, 23:00–04:59; getting up/breakfast, 05:00–08:59; indoor activities/going out, 09:00–16:59; and dinner/going to bed, 17:00–22:59) and the average outputs from the sensors in the rooms. The subject was then monitored for a further six months. By identifying sensor output counts outside the limits of mean ±3SD, we were able to detect atypical days. During the six-month monitoring period, 29 atypical days were detected. We suggest that the monitoring system may be effective in tele-rehabilitation.

Maladaptive change of body representation in the brain after damage to central or peripheral nervous system

Our brain has great flexibility to cope with various changes in the environment. Use-dependent plasticity, a kind of functional plasticity, plays the most important role in this ability to cope. For example, the functional recovery of paretic limb motor movement during post-stroke rehabilitation depends mainly on how much it is used. Patients with hemiparesis, however, tend to gradually disuse the paretic limb because of its motor impairment. Decreased use of the paretic hand then leads to further functional decline brought by use-dependent plasticity. To break this negative loop, body representation, which is the conscious and unconscious information regarding body state stored in the brain, is key for using the paretic limb because it plays an important role in selecting an effector while a motor program is generated. In an attempt to understand body representation in the brain, we reviewed animal and human literature mainly on the alterations of the sensory maps in the primary somatosensory cortex corresponding to the changes in limb usage caused by peripheral or central nervous system damage.

The neural basis of the imitation drive

Spontaneous imitation is assumed to underlie the acquisition of important skills by infants, including language and social interaction. In this study, functional magnetic resonance imaging (fMRI) was used to examine the neural basis of ‘spontaneously’ driven imitation, which has not yet been fully investigated. Healthy participants were presented with movie clips of meaningless bimanual actions and instructed to observe and imitate them during an fMRI scan. The participants were subsequently shown the movie clips again and asked to evaluate the strength of their ‘urge to imitate’ (Urge) for each action. We searched for cortical areas where the degree of activation positively correlated with Urge scores; significant positive correlations were observed in the right supplementary motor area (SMA) and bilateral midcingulate cortex (MCC) under the imitation condition. These areas were not explained by explicit reasons for imitation or the kinematic characteristics of the actions. Previous studies performed in monkeys and humans have implicated the SMA and MCC/caudal cingulate zone in voluntary actions. This study also confirmed the functional connectivity between Urge and imitation performance using a psychophysiological interaction analysis. Thus, our findings reveal the critical neural components that underlie spontaneous imitation and provide possible reasons why infants imitate spontaneously.

Induction of neurite outgrowth in PC12 cells treated with temperature-controlled repeated thermal stimulation

To promote the functional restoration of the nervous system following injury, it is necessary to provide optimal extracellular signals that can induce neuronal regenerative activities, particularly neurite formation. This study aimed to examine the regulation of neuritogenesis by temperature-controlled repeated thermal stimulation (TRTS) in rat PC12 pheochromocytoma cells, which can be induced by neurotrophic factors to differentiate into neuron-like cells with elongated neurites. A heating plate was used to apply thermal stimulation, and the correlation of culture medium temperature with varying surface temperature of the heating plate was monitored. Plated PC12 cells were exposed to TRTS at two different temperatures via heating plate (preset surface temperature of the heating plate, 39.5°C or 42°C) in growth or differentiating medium for up to 18 h per day. We then measured the extent of growth, neuritogenesis, or acetylcholine esterase (AChE) activity (a neuronal marker). To analyze the mechanisms underlying the effects of TRTS on these cells, we examined changes in intracellular signaling using the following: tropomyosin-related kinase A inhibitor GW441756; p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580; and MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor U0126 with its inactive analog, U0124, as a control. While a TRTS of 39.5°C did not decrease the growth rate of cells in the cell growth assay, it did increase the number of neurite-bearing PC12 cells and AChE activity without the addition of other neuritogenesis inducers. Furthermore, U0126, and SB203580, but not U0124 and GW441756, considerably inhibited TRTS-induced neuritogenesis. These results suggest that TRTS can induce neuritogenesis and that participation of both the ERK1/2 and p38 MAPK signaling pathways is required for TRTS-dependent neuritogenesis in PC12 cells. Thus, TRTS may be an effective technique for regenerative neuromedicine.

Cbfb regulates bone development by stabilizing Runx family proteins

Runx family proteins, Runx1, Runx2, and Runx3, play important roles in skeletal development. Runx2 is required for osteoblast differentiation and chondrocyte maturation, and haplodeficiency of RUNX2 causes cleidocranial dysplasia, which is characterized by open fontanelles and sutures and hypoplastic clavicles. Cbfb forms a heterodimer with Runx family proteins and enhances their DNA-binding capacity. Cbfb-deficient (Cbfb(-/-) ) mice die at midgestation because of the lack of fetal liver hematopoiesis. We previously reported that the partial rescue of hematopoiesis in Cbfb(-/-) mice revealed the requirement of Cbfb in skeletal development. However, the precise functions of Cbfb in skeletal development still remain to be clarified. We deleted Cbfb in mesenchymal cells giving rise to both chondrocyte and osteoblast lineages by mating Cbfb(fl/fl) mice with Dermo1 Cre knock-in mice. Cbfb(fl/fl/Cre) mice showed dwarfism, both intramembranous and endochondral ossifications were retarded, and chondrocyte maturation and proliferation and osteoblast differentiation were inhibited. The differentiation of chondrocytes and osteoblasts were severely inhibited in vitro, and the reporter activities of Ihh, Col10a1, and Bglap2 promoter constructs were reduced in Cbfb(fl/fl/Cre) chondrocytes or osteoblasts. The proteins of Runx1, Runx2, and Runx3 were reduced in the cartilaginous limb skeletons and calvariae of Cbfb(fl/fl/Cre) embryos compared with the respective protein in the respective tissue of Cbfb(fl/fl) embryos at E15.5, although the reduction of Runx2 protein in calvariae was much milder than that in cartilaginous limb skeletons. All of the Runx family proteins were severely reduced in Cbfb(fl/fl/Cre) primary osteoblasts, and Runx2 protein was less stable in Cbfb(fl/fl/Cre) osteoblasts than Cbfb(fl/fl) osteoblasts. These findings indicate that Cbfb is required for skeletal development by regulating chondrocyte differentiation and proliferation and osteoblast differentiation; that Cbfb plays an important role in the stabilization of Runx family proteins; and that Runx2 protein stability is less dependent on Cbfb in calvariae than in cartilaginous limb skeletons.

Ultrasound elastography-based assessment of the elasticity of the supraspinatus muscle and tendon during muscle contraction

BACKGROUND

Although elasticity of the supraspinatus muscle and tendon is a useful parameter to represent the conditions of the supraspinatus muscle and tendon, assessment of the elasticity in clinical settings has not been established. The purpose of this study was to determine the elasticity of the supraspinatus muscle belly and tendon under different muscle contraction conditions using ultrasound real-time tissue elastography (RTE).

METHODS

Twenty-three healthy individuals participated in this study. Ultrasound RTE was used for elasticity measurements of the muscle belly and tendon of the supraspinatus muscle. The elasticity was defined as the ratio of strain in the tissues to that in an acoustic coupler (reference). A greater ratio indicated that the tissue was softer. Measurements were performed with study subjects in the lateral decubitus position at 10° of shoulder abduction under conditions of (1) no contraction, (2) isometric contraction without a weight, and (3) isometric contraction with a 1-kg weight.

RESULTS

The intraclass correlation coefficient (ICC1,3) of 3 measurements under each condition ranged from 0.931 to 0.998, showing high intraobserver reliability. Strain ratios for both the supraspinatus muscle belly and tendon significantly decreased with increases in muscle contraction (P < .001).

CONCLUSIONS

Ultrasound RTE with the acoustic coupler has the potential to noninvasively detect changes in the elasticity of the supraspinatus muscle belly and tendon that accompany varying levels of muscle contraction in clinical practice.

Dlx5 and mef2 regulate a novel runx2 enhancer for osteoblast-specific expression

Runx2 is essential for osteoblast differentiation and chondrocyte maturation. The expression of Runx2 is the first requisite step for the lineage determination from mesenchymal stem cells to osteoblasts. Although the transcript from Runx2 distal promoter is majorly expressed in osteoblasts, the promoter failed to direct green fluorescent protein (GFP) expression to osteoblasts. To find the regulatory region, we generated GFP reporter mice driven by a bacterial artificial chromosome (BAC) of Runx2 locus, and succeeded in the reproduction of endogenous Runx2 expression. By serially deleting it, we identified a 343-bp enhancer, which directed GFP expression specifically to osteoblasts, about 30 kb upstream of the distal promoter. The sequence of the 343-bp enhancer was highly conserved among mouse, human, dog, horse, opossum, and chicken. Dlx5, Mef2c, Tcf7, Ctnnb1, Sp7, Smad1, and Sox6, which localized on the enhancer region in primary osteoblasts, synergistically upregulated the enhancer activity, whereas Msx2 downregulated the activity in mouse osteoblastic MC3T3-E1 cells. Msx2 was predominantly bound to the enhancer in mouse multipotent mesenchymal C3H10T1/2 cells, whereas Dlx5 was predominantly bound to the enhancer in MC3T3-E1 cells. Dlx5 and Mef2 directly bound to the enhancer, and the binding sites were required for the osteoblast-specific expression in mice, whereas the other factors bound to the enhancer by protein-protein interaction. The enhancer was characterized by the presence of the histone variant H2A.Z, the enrichment of histone H3 mono- and dimethylated at Lys4 and acetylated at Lys18 and Lys27, but the depletion of histone H3 trimethylated at Lys4 in primary osteoblasts. These findings indicated that the enhancer, which had typical histone modifications for enhancers, contains sufficient elements to direct Runx2 expression to osteoblasts, and that Dlx5 and Mef2, which formed an enhanceosome with Tcf7, Ctnnb1, Sp7, Smad1, and Sox6, play an essential role in the osteoblast-specific activation of the enhancer. © 2014 American Society for Bone and Mineral Research.

[The mirror neuron system in motor and sensory rehabilitation]

The discovery of the mirror neuron system has dramatically changed the study of motor control in neuroscience. The mirror neuron system provides a conceptual framework covering the aspects of motor as well as sensory functions in motor control. Previous studies of motor control can be classified as studies of motor or sensory functions, and these two classes of studies appear to have advanced independently. In rehabilitation requiring motor learning, such as relearning movement after limb paresis, however, sensory information of feedback for motor output as well as motor command are essential. During rehabilitation from chronic pain, motor exercise is one of the most effective treatments for pain caused by dysfunction in the sensory system. In rehabilitation where total intervention unifying the motor and sensory aspects of motor control is important, learning through imitation, which is associated with the mirror neuron system can be effective and suitable. In this paper, we introduce the clinical applications of imitated movement in rehabilitation from motor impairment after brain damage and phantom limb pain after limb amputation.

Galnt3 deficiency disrupts acrosome formation and leads to oligoasthenoteratozoospermia

Galnt3 belongs to the GalNAc transferase gene family involved in the initiation of mucin-type O-glycosylation. Male Galnt3-deficient (Galnt3(-/-)) mice were infertile, as previously reported by Ichikawa et al. (2009). To investigate the involvement of Galnt3 in spermatogenesis, we examined the differentiation of germ cells in Galnt3(-/-) mice. Galnt3 mRNA was most highly expressed in testis, and Galnt3 protein was localized in the cis-medial parts of the Golgi stacks of spermatocytes and spermatids in the seminiferous tubules. Spermatozoa in Galnt3(-/-) mice were rare and immotile, and most of them had deformed round heads. They exhibited abnormal acrosome and disturbed mitochondria arrangement in the flagella. At the cap phase, proacrosomal vesicles of various sizes, which had not coalesced to form a single acrosomal vesicle, were attached to the nucleus in Galnt3(-/-) mice. TUNEL-positive cells were increased in the seminiferous tubules. The binding of VVA lectin, which recognizes the Tn antigen (GalNAc-O-Ser/Thr), in the acrosomal regions of spermatids and spermatozoa in Galnt3(-/-) mice was drastically reduced. Equatorin is a N, O-sialoglycoprotein localized in the acrosomal membrane and is suggested to be involved in sperm-egg interaction. Immunohistochemical and Western blot analyses showed a drastic reduction in the reactivity with MN9 antibody, which recognizes the O-glycosylated moiety of equatorin and inhibits sperm-egg interaction. These findings indicate that deficiency of Galnt3 results in a severe reduction of mucin-type O-glycans in spermatids and causes impaired acrosome formation, leading to oligoasthenoteratozoospermia, and suggest that Galnt3 may also be involved in the process of fertilization through the O-glycosylation of equatorin.

Pyruvate dehydrogenase kinase 4 induces bone loss at unloading by promoting osteoclastogenesis

Disuse osteoporosis, which occurs commonly in prolonged bed rest and immobilization, is becoming a major problem in modern societies; however, the molecular mechanisms underlying unloading-driven bone loss have not been fully elucidated. The osteocyte network is considered to be an ideal mechanosensor and mechanotransduction system. We searched for the molecules responsible for disuse osteoporosis using BCL2 transgenic mice, in which the osteocyte network was disrupted. Pyruvate dehydrogenase kinase 4 (Pdk4), which inactivates pyruvate dehydrogenase complex (PDC), was upregulated in femurs and tibiae of wild-type mice but not of BCL2 transgenic mice after tail suspension. Bone in Pdk4(-/-) mice developed normally and was maintained. At unloading, however, bone mass was reduced due to enhanced osteoclastogenesis and Rankl expression in wild-type mice but not in Pdk4(-/-) mice. Osteoclast differentiation of Pdk4(-/-) bone marrow-derived monocyte/macrophage lineage cells (BMMs) in the presence of M-CSF and RANKL was suppressed, and osteoclastogenesis was impaired in the coculture of wild-type BMMs and Pdk4(-/-) osteoblasts, in which Rankl expression and promoter activity were reduced. Further, introduction of Pdk4 into Pdk4(-/-) BMMs and osteoblasts enhanced osteoclastogenesis and Rankl expression and activated Rankl promoter. These findings indicate that Pdk4 plays an important role in bone loss at unloading by promoting osteoclastogenesis.

Early onset of Runx2 expression caused craniosynostosis, ectopic bone formation, and limb defects

RUNX2 is an essential transcription factor for osteoblast differentiation, because osteoblast differentiation is completely blocked in Runx2-deficient mice. However, it remains to be clarified whether RUNX2 is sufficient for osteoblast differentiation during embryogenesis. To address this issue, Runx2 transgenic mice were generated under the control of the Prrx1 promoter, which directs the transgene expression to mesenchymal cells before the onset of bone development. The transgene expression was detected in the cranium, limb buds, and the region from the mandible to anterior chest wall. The skull became small and the limbs were shortened depending on the levels of the transgene expression. Early onset of Runx2 expression in the cranial mesenchyme induced mineralization on E13.0, when no mineralization was observed in wild-type mice, and resulted in craniosynostosis as shown by the closure of sutures and fontanelles on E18.5. Col1a1 and Spp1 expressions were detected in the mineralized regions on E12.5-13.5. The limb bones were hypoplastic and fused, and ectopic bones were formed in the hands and feet. Col2a1 expression was inhibited but Col1a1 expression was induced in the limb buds on E12.5. In the anterior chest wall, ectopic bones were formed through the process of intramembranous ossification, interrupting the formation of cartilaginous anlagen of sternal manubrium. These findings indicate that RUNX2 is sufficient to direct mesenchymal cells to osteoblasts and lead to intramembranous bone formation during embryogenesis; Runx2 inhibits chondrocyte differentiation at an early stage; and that Runx2 expression at appropriate level, times and spaces during embryogenesis is essential for skeletal development.

Immobilization-induced cartilage degeneration mediated through expression of hypoxia-inducible factor-1alpha, vascular endothelial growth factor, and chondromodulin-I

Immobilization results in thinning of the articular cartilage and cartilage degeneration, although the exact mechanisms are not clear yet. Hypoxia is thought to contribute to the degeneration of articular cartilage. We investigated the roles of hypoxia inducible factor (HIF)-1alpha, vascular endothelial growth factor (VEGF), and the newly cloned antiangiogenic factor, chondromodulin-I (ChM-1), in cartilage degeneration in immobilized joints. Male Wistar rats (n = 30, 12-week-old) were divided randomly into the control group (n = 10), immobilization group (n = 10), and continuous passive motion (CPM) group (n = 10). In the immobilization group, the ankle joints were fixed in full plantar flexion with plaster casts for 4 weeks. In the CPM group, the ankle casts were removed during the immobilization period and the ankle joints were subjected to CPM. Significant thinning of the articular cartilage was noted in the immobilization group but not in the control or CPM group. In the immobilized group, vascular channels were found in the area between the calcified cartilage zone and the subchondral bone. The densities of HIF-1alpha-and VEGF-immunostained cells were higher in the immobilized group than the other two groups. In contrast, low expression of ChM-1 was detected in the articular cartilage of the immobilized group compared with the control and CPM group. Our results showed that immobilization induces thinning of the articular cartilage and appearance of vascular channel, in areas with balanced expression of HIF-1alpha/VEGF and ChM-1.

Plasma fibrinogen, ambulatory blood pressure, and silent cerebrovascular lesions: the Ohasama study

OBJECTIVE

Twenty-four-hour ambulatory blood pressure (24-hour ABP) values are considered a powerful predictor of stroke. Silent cerebrovascular lesions are associated with an increased risk of stroke. Because fibrinogen is a major determinant of plasma viscosity, an elevated fibrinogen level might also be associated with stroke risk. We evaluated the association of 24-hour ABP and plasma fibrinogen levels with the risk of silent cerebrovascular lesions (white matter hyperintensity and lacunar infarct) detected by MRI.

METHODS AND RESULTS

The study cohort comprised 958 individuals from the general population of Ohasama, a rural Japanese community. Multiple logistic regression analysis adjusted for age, sex, smoking and drinking status, use of antihypertensive medication, body mass index, 24-hour ABP, and a history of hypercholesterolemia, diabetes mellitus, and atrial fibrillation demonstrated that each 1-SD increase in fibrinogen level was associated with a significantly increased risk of silent cerebrovascular lesions (odds ratio, 1.26; P=0.001). The 24-hour ABP was also significantly and independently associated with the risk of silent cerebrovascular lesions. Even when 24-hour ABP values were within normal range (<135/80 mm Hg), elevated fibrinogen levels were associated with an increased risk of silent cerebrovascular lesions. Fibrinogen and 24-hour BP had additive effects on silent cerebrovascular lesions.

CONCLUSION

The 24-hour ABP and plasma fibrinogen levels were closely and independently associated with the risk of silent cerebrovascular lesions including white matter hyperintensity and lacunar infarct.

Anti-annexin A5 Antibodies in Reproductive Failures in Relation to Antiphospholipid Antibodies and Phosphatidylserine

PROBLEM

The presence of IgG anti-annexin A5 (IgGalphaA5) and/or antiphospholipid antibodies (aPL) are risk factors associated with recurrent spontaneous abortion. Problems are whether IgA antiannexin A5 (IgAalphaA5) is pathogenic, and how IgGalphaA5 works.

METHOD OF STUDY

Blood samples from 238 patients with early recurrent spontaneous abortion, 48 patients with recurrent in vitro fertilization-embryo transfer failure, 179 non-pregnant women and 120 pregnant controls were tested for IgAalphaA5 by enzyme-linked immunosorbent assay. We also determined if IgGalphaA5 appeared coincident with aPL. The antigenic epitope(s) recognized by IgGalphaA5 was investigated.

RESULTS

We observed no difference between patients and controls for IgAalphaA5. The prevalence of IgGalphaA5 was not different statistically between patient samples with or without aPL. Patient IgGalphaA5 bound annexin A5 when the latter was free/unbound but not when annexin A5 was associated with phospholipid.

CONCLUSIONS

The IgAalphaA5 does not appear to be pathogenic. IgGalphaA5 works to make a complex with annexin A5 without relation to aPLs, which may reduce annexin A5 available for binding to trophoblast.

Molecular histochemical analysis of estrogen receptor alpha and beta expressions in the mouse ovary: in situ hybridization and Southwestern histochemistry

It is well known that estrogen plays important roles in the female reproductive organs, including the ovary, through estrogen receptors (ERalpha and ERbeta). It is suggested that selective effects of estrogen on a discrete set of genes may reside in promoters that are differentially responsive to ERalpha and ERbeta, while the relative biological significance of ERalpha and ERbeta is unclear. Therefore, for a better understanding of the physiological and pathological states of ovarian cells, it seems to be essential to analyze the cellular expression of ERalpha and ERbeta, at both the protein and mRNA levels. For this purpose, we have optimized the protocols for immunohistochemistry and nonradioactive in situ hybridization, respectively, using the mouse ovary. These techniques have been established as useful histochemical methods for the localization of specific protein and/or mRNA expression at the cellular level. Moreover, we also attempted to evaluate ERs as binding proteins to estrogen responsive elements, using Southwestern histochemistry, which permits us to analyze the localization in situ of transcription regulatory proteins. By employing these methods, more precise understanding of specific gene expression and evaluation of its biological significance in the ovary would be possible.

Diethylstilbestrol attenuates antioxidant activities in testis from male mice

It has been reported that acute exposure to diethylstilbestrol (DES) induces apoptosis in the testis, and antioxidants play a role in preventing DES-induced tissue damage. In this study, the effect of chronic exposure to DES on the antioxidants was examined in the testis and liver. Eight-week old male ICR mice were treated subcutaneously with various doses of DES for 20 days. Morphologically apparent apoptotic changes, 4-hydroxy-2-nonenal-positive cells and TUNEL-positive DNA-fragmentation, were demonstrated in the testis, but were minimal in the liver. Activities of antioxidants such as glutathione (GSH) peroxidase and GSH S-transferase decreased in both the liver and testis. The activity of Mn-superoxide dismutase (SOD) decreased in the liver but increased in the testis. The activity of Cu, Zn-SOD decreased in the liver but was unchanged in the testis. On Western and Northern blots, gamma-glutamylcysteine synthetase (gamma-GCS), a rate limiting enzyme of GSH synthesis, was increased in the liver dependent on the dose of DES. However, the expression of gamma-GCS was reduced in the testis. Since quinones, metabolites of DES, generate reactive oxygen species, which damage DNA, antioxidants are important to prevent the damage. The data suggest that antioxidant activities are impaired by DES, and the levels of GSH are related to DES-induced apoptosis in the testis.

The nature of facilitation of leg muscle motor evoked potentials by knee flexion

Knee flexion is a movement that initiates rising from a sitting position, which is a common therapeutic exercise for patients unable to ambulate. We investigated how voluntary isometric biceps femoris contraction affects motor evoked potential (MEP) amplitude following transcranial magnetic stimulation, background electromyographic (EMG) amplitude, and H-reflex amplitude in ipsilateral leg muscles. Subjects were seated on the edge of a bed with their hips and knees flexed at 90 degrees, and the soles of their feet on the floor. MEP and background EMG were recorded from the tibialis anterior (TA) and soleus (SOL), and H reflexes from SOL of 30 volunteers. Background EMG and MEP also were recorded while voluntarily contracting tested muscles. Biceps femoris contraction increased MEP and background EMG for TA and SOL (p < 0.01). Maximal background EMG and MEP increased with increasing voluntary contraction of tested muscles (p < 0.005). Regression slope differed little between TA and SOL. Biceps femoris contraction facilitated MEP comparably for TA and SOL, while SOL background EMG exceeded that of TA (p < 0.02). The relationship between MEP facilitation and background EMG changed to favor more efficient facilitation in TA (p < 0.05), but not SOL (p > 0.1). MEP recorded from TA and SOL with subthreshold stimuli using needle electrodes were more frequent with biceps femoris contraction (p < 0.04). H-reflex amplitude of SOL decreased during biceps femoris contraction (p < 0.001). We concluded that biceps femoris contraction affects leg muscle MEP, background EMG, and H reflexes differently.

Involvement of Fas/Fas ligand in the induction of apoptosis in chronic sialadenitis of minor salivary glands including Sjögren's syndrome

The role of apoptosis and contribution of Fas/FasL systems in the pathogenesis of Sjogren's syndrome (SS) are still controversial. With serial sections, we explored apoptosis assessed by the dUTP nick end labeling (TUNEL) method and expression of Fas and FasL by immunohistochemistry, and compared their distribution in minor salivary gland (MSG) of SS and sialolithiasis (SIL) patient tissues. Fas and FasL were co-localized in ductular and acinar cells of SS and SIL TUNEL+ cells co-distributed with the Fas and FasL expressing cells in ductular and acinar cells of SS in the vicinity of lymphocytic infiltration, while not in those of SIL Moreover, to morphologically confirm apoptosis, we identified TUNEL-positive(+) cells in the MSGs of SS at the ultra structural level by applying an inversion method to paraffin-embedded sections stained by TUNEL method. Surprisingly, these cells did not show characteristic apoptotic figures although TUNEL products were deposited on the hyperchromatin of acinar and ductular cells. On the other hand, acinar and ductular cells of SIL included clusters of TUNEL+ apoptotic bodies as did those cells by phagocytosis or having fallen into the ductular lumen. These findings suggest that Fas and FasL expressed in ducts and acini of chronic sialadenitis in SS patients induce apoptosis, possibily in an autocrine and/or paracrine manner.

Presence of aldose reductase inhibitors in tea leaves

Water extract from commercial English tea has a potent inhibitory activity against human placenta aldose reductase (NADPH oxidoreductase, E.C.1.1.1.21.). Inhibitory activity was separated into five major fractions by one-step chromatography with a C-18 reverse phase column. The most active fraction was further subjected to reverse phase column chromatography. As a result, a well-known flavone-glycoside, isoquercitrin, was isolated as the most potent chemical. The inhibitory character of isoquercitrin for aldose reductase was a mix of uncompetitive and noncompetitive inhibitions, and its IC50 was 1 x 10(-6) M. In rat sciatic nerve tissue preparations, sorbitol accumulation in the presence of high concentrations of glucose (30 mM) was inhibited by 38% at 5 x 10(-4) M of isoquercitrin. The flavone-glycoside isoquercitrin is the active inhibitor of aldose reductase inhibitor present in English tea. Given the ability of aldose reductase inhibitors to prevent diabetic complications, an epidemiological study of the effect of tea consumption on the pathogenesis and progression of diabetic complications would be interesting.

Memory rehabilitation of an amnesic patient following limbic encephalitis and a role of family members: a case report

We describe problems in daily living that arose in a 46-year-old man with severe amnesia following limbic encephalitis. Amnesic symptoms changed from stage I (difficulty in memory retention) to stage II (loss of continuity of memory) and finally to stage III (paramnesia and confused sequence of events), significantly affecting his ability to function. Questionnaire response assessment, directly observed behavior, neuropsychological testing, and especially interviewing permitted qualitative assessment of clinical changes, promoted patient insight into the memory disturbance, and enhanced motivation to use a memory notebook. Additionally, the family gained a better understanding of the disorder, made appropriate environmental modifications, and provided other necessary assistance. Episodic memory improved, and the memory notebook served as an effective compensatory tool. However, disturbance in prospective memory did not improve, and was not compensated adequately by use of the notebook. Anxiety and significant impairment of everyday functioning resulted. Long-term supportive intervention at home was necessary. The patient's wife in particular needed to make environmental adjustments and aid him in use of the notebook.

Anti-paternal antibodies by flow cytometry in the management of alloimmunization on recurrent miscarriages

PROBLEM

There is no reliable laboratory test available to diagnose immunologically mediated miscarriages. We investigated the clinical significance of maternal anti-paternal leukocyte antibodies by flow cytometry after alloimmunization.

METHOD OF STUDY

The flow cytometry crossmatch (FCXM) was performed in 158 patients with a history of three or more unexplained first-trimester miscarriages without live birth. After negative FCXM patients were immunized, subsequent pregnancy outcomes and FCXM results were followed.

RESULTS

Of 112 subsequent pregnancies, 83 of 100 (83.0%) FCXM-positive patients after immunotherapy had successful pregnancy outcomes, whereas seven of 10 (70.0%) FCXM-negative patients had miscarriages (P = 0.0001). The percent live birth ratio was 2.77 (CI, 1.07-7.16; P=0.0001) for FCXM-positive patients compared to FCXM-negative patients. The calculated predictive value showed that 75.6% of FCXM-negative patients would have subsequent miscarriages.

CONCLUSIONS

Positive FCXM is closely associated with successful pregnancy outcome following immunotherapy. We propose that FCXM might be included in the routine laboratory tests for the management of recurrent miscarriages.

Relationship between hypoxemia and fibrillation potential firing rate in denervated muscle

The effects of hypoxia and ischemia on the firing rate of fibrillation potentials in denervated rat muscle were examined. We recorded electromyograms from the denervated left extensor digitorum longus muscle. Hypoxia was induced by low-oxygen ventilation. Ischemia was established by ligating the abdominal aorta and inferior vena cava, with or without extracorporeal hindlimb perfusion. The fibrillation potential firing rate correlated with the PaO2 (P < 0.0001) and temperature (P = 0.0001). Fibrillation potentials disappeared after the initiation of ischemia and reappeared after restitution of blood flow; they disappeared during ischemia with extracorporeal perfusion. The attenuation curves for the firing rate of fibrillation potentials during ischemia were well-described by exponential curves, but there was no significant difference in the attenuation constants for circulatory arrest and perfusion with a physiologic salt solution. We conclude that the fibrillation potential firing rate is proportional to oxygen supply, presumably because of the rate of aerobic metabolism.

Effects of dantrolene sodium on fibrillation potentials in denervated rat muscles

To examine whether a decrease in cytosolic Ca2+ affects fibrillation potentials, we studied effects of dantolene on these potentials in denervated rat muscle. Administered intraperitoneally, dantrolene sodium (12-22 mg/kg) abolished fibrillation potentials and subthreshold oscillating potentials over 2.5-6 h without affecting excitability of the muscle to electrical stimulation. Fibrillation potentials reappeared 36-96 h after administration of dantrolene. We suggest that cytosolic Ca2+ has a specific role in generating fibrillations.

An individual patient comparison of response to a memory training program--psychogenic V organic amnesia: brief report

Psychogenic amnesia ("dissociative amnesia" in DSM-IV) has received relatively little attention in the literature. We compared neuropsychological and behavioral findings between a patient with psychogenic amnesia and one with organic amnesia from their early stages in a rehabilitation program. A 52-yr-old man developed anterograde and retrograde amnesia and short-term memory disturbance 1 mo after an operation for esophageal carcinoma, with no loss of personal identity and information. No apparent organic causes were identified, but because the patient and his wife rejected psychiatric treatment and memory deficit characteristics were compatible with that of an organic origin, the patient was referred to a physiatrist. A 46-yr-old man with anterograde amnesia was diagnosed with limbic encephalitis based on findings of magnetic resonance imaging and single-photon emission computed tomography, which showed lesions in both medial temporal lobes. Both patients underwent "memory book" training because they showed preserved performance in motor learning tasks. The first patient's responses to training contrasted with the other's and were indicative of psychogenic amnesia, with cancer representing a precipitating stress. Counseled by the physiatrist, the patient and his wife accepted suggestions to undergo psychiatric treatment. We propose that it is important to consider behavioral responses to memory rehabilitation as well as neuropsychological findings in differentiating psychogenic amnesia from an organic one and that physiatrists may be pivotal in diagnosing and initiating treatment in such psychiatric disorders.

Solubilization and characterization of the rat pituitary gonadotrophin-releasing hormone receptor

Specific receptors for gonadotrophin-releasing hormone (GnRH) were extracted from the rat pituitary gland with several detergents and characterized by binding studies with the potent GnRH antagonist [Ac-D-pCl-Phe1.2, D-Trp3, D-Lys6, D-Ala10]-GnRH (GnRHant). The particulate GnRH receptors were most effectively solubilized with 5 mM 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulphonate (CHAPS), which extracted 63% of the original membrane binding activity when assayed with 125I-labelled GnRHant. The binding affinities of particulate and CHAPS-solubilized receptors analysed with 125I-labelled GnRHant were 1.5 +/- 0.4 x 10(9) M-1 and 1.2 +/- 0.2 x 10(9) M-1 respectively. Gel filtration of the CHAPS-solubilized receptor revealed a major peak of specific binding activity with Mr of about 700,000. A hormone-receptor complex of similar Mr was observed when CHAPS-solubilized receptors were labelled with photoreactive radioiodinated [D-Lys6]-des-Gly10-GnRH-N-ethyl-amide and then analysed by gel chromatography. However, when pituitary particles were photolabelled and solubilized in 2% Triton X-100 before analysis on Sephacryl S-300, the Mr of the receptor was approximately 250,000, similar to the value obtained by sucrose density gradient centrifugation of the CHAPS-solubilized receptor. After solubilization in sodium dodecyl sulphate (SDS) the photolabelled receptor was eluted from Sephacryl S-300 as a 60 kDa peak which on SDS-gel electrophoresis contained a 52 kDa component, corresponding to the major binding subunit extracted directly from photolabelled pituitary membranes. The difference in higher molecular weight forms observed under non-denaturing and denaturing conditions could reflect the need for additional membrane components to maintain the active conformation of the GnRH receptor site. Whereas the minimum Mr of the solubilized receptor is about 250,000 under non-denaturing conditions, analysis of the photolabelled GnRH-receptor complex by SDS chromatography and electrophoresis indicates that a binding subunit with Mr of 50,000-60,000 is present in the GnRH holoreceptor.