Association between the executive dysfunction and balance function in patients with stroke.

INTRODUCTION: A previous study has shown an association between executive dysfunction (ED) and balance function in patients with stroke. However, it is unclear what factors mediate the association between ED and balance function. Therefore, the aim of this study was to investigate the association between ED and balance function and to identify mediating factors using mediation analysis. METHODS: This study had a cross-sectional design. The study included 107 patients with stroke. This study was divided into two groups (ED and non-ED) using trail making test (TMT) part B. Two groups were compared for balance function (timed up and go test [TUGT] and Berg balance scale [BBS]) and other variables using paired test. In addition, partial correlation analysis with age, cognitive function as a control factor, and mediation analysis were also performed. RESULTS: The ED group (N = 55) had significantly lower TUGT and BBS scores than the non-ED group (N = 52). TMT part B correlated with TUGT (ρ = 0.41), BBS (ρ = -0.33), and Brunnstrom recovery stage (BRS) lower limb (ρ = -0.22). The TUGT model of mediation analysis showed a significant indirect effect as a result of mediation of the BRS lower limb between TMT part B and TUGT. The BBS model showed a significant indirect effect as a result of mediation of the activities of daily living (ADL) motor function between TMT part B and BBS. CONCLUSIONS: ED and balance function were associated, and the degree of paralysis and ADL motor function were associated with them in patients with stroke.

Estimation Error Consisting of Motor Imagery and Motor Execution in Patients with Stroke.

Previous studies demonstrate that the difference between motor imagery and actual tasks (estimation error) is related to cognitive and physical functions and that a large estimation error (LE) is related to motor imagery ability, including cognitive and physical functions in healthy subjects. The purpose of this study investigated whether estimation error is related to physical and cognitive function in patients with stroke. The study included 60 patients with stroke. The Timed Up and Go Test (TUGT) was employed to assess estimation error. First, the imagined TUGT (iTUGT) was performed; thereafter, the actual TUGT was performed. The estimation error was calculated by subtracting TUGT from iTUGT, with conversion to the absolute value. The patients were classified into the small estimation error (SE) and LE groups, with comparisons of various clinical scores (Mini-Mental State Examination, Berg Balance Scale, 10-m walking speed, Brunnstrom Recovery Stage, and Functional Independence Measure). As a result, the estimation error was significantly larger in the LE group than in the SE group. Cognitive function and balance ability were significantly lower in the LE group than in the SE group. In conclusion, the estimation error was related to physical and cognitive functions in patients with stroke.

Walking Ability Associated with Executive Dysfunction in Patients with Stroke: A Cross-Sectional Study.

Previous studies have shown an association between executive dysfunction and walking ability. However, it remains unclear whether the degree of executive dysfunction is associated with differences in walking ability in patients with stroke. The aim of this study was to investigate whether there are differences in walking ability according to executive dysfunction in patients with stroke. A total of 51 patients with stroke were enrolled in this study. Executive function was measured using the Trail Making Test (TMT) Part B, and walking ability was assessed using the 10 m walk test and the Timed Up and Go Test (TUGT). Cluster analysis was performed using the TMT Part B and compared within each cluster. TMT Part B was categorized into three groups (cluster 1: n = 20, cluster 2: n = 24, and cluster 3: n = 7). Cluster 1 was significantly better than clusters 2 and 3, and cluster 2 was significantly better than cluster 3. The 10 m walk time and TUGT of cluster 1 were significantly better than those of cluster 3. However, the 10 m walk time and TUGT of clusters 1 and 2 did not differ significantly. In conclusion, these findings may indicate differences in walking ability according to executive dysfunction.

Overestimation associated with walking and balance function in individuals diagnosed with a stroke.

BACKGROUND: An estimation error is the difference between motor imagery and actual motor time. Previous studies have reported that overestimation (motor imagery time < actual motor time) is related to physical functions in healthy individuals. However, this finding is unclear among individuals diagnosed with a stroke. OBJECTIVE: We investigated whether overestimation is related to physical function in individuals diagnosed with a stroke. METHODS: This study included 71 individuals diagnosed with a stroke (mean age, 67.2 ± 13.4 years; mean time since stroke, 68.4 ± 44.7 days). Imagined timed up and go test (iTUGT) was performed to assess the estimation error. First, the iTUGT was performed; subsequently, the TUGT was performed. The estimation error was calculated by subtracting the TUGT from the iTUGT, with two standard deviations (2 SDs) being calculated. Furthermore, patients were classified into appropriate estimation (AE, within ±2 SD) and overestimation (OE, over -2 SD) groups. Both groups were tested using the estimation error, iTUGT, TUGT, Berg Balance Scale (BBS), and Brunnstrom Recovery Stage (BRS). Subsequently, a correlation analysis was performed. RESULTS: The OE group had a significantly higher estimation error than the AE group (OE: -7.08 ± 6.87 s, AE: -0.29 ± 1.53 s, P < .001). Moreover, the OE group had significantly lower TUGT and BBS than the AE group. The estimation error was correlated with the TUGT, BBS, and lower-limb BRS (ρ = -0.454, 0.431, 0.291, respectively; P < .05). CONCLUSIONS: Overestimation was associated with TUGT and balance function in individuals diagnosed with a stroke.

Survey of Glasgow Coma Scale and PaO2/FIO2 ratio assessment methods for the Sequential Organ Failure Assessment score in Japanese intensive care units.

Aim: Accurately calculating the Sequential Organ Failure Assessment (SOFA) score is essential for medical resource allocation and decision-making. This study surveyed Japanese intensive care units regarding their assessment of the Glasgow Coma Scale (GCS) and PaO2/FIO2 ratio, components of the SOFA score. Methods: A cross-sectional, web-based survey was conducted among healthcare workers. The survey consisted of questions about the intensive care units where they work and questions for respondents. It was distributed to healthcare workers by e-mail through the Japanese Society of Intensive Care Medicine mailing list and social networking service. Results: Among 414 responses, we obtained 211 valid responses and 175 survey results from unique intensive care units. When assessing GCS in patients under the influence of sedatives, 45.1% (95% confidence interval, 37.6-52.8) of intensive care units assessed GCS assuming that the sedatives had no influence. For the PaO2/FIO2 ratio in the SOFA score, calculation based on the Japanese Intensive Care Patient Database definition document and mechanical ventilator settings were the most common methods in patients with oxygen masks and on extracorporeal membrane oxygenation, respectively. Approximately 60% of respondents indicated that it was difficult to assess GCS assuming that sedatives had no influence. Conclusion: In patients under the influence of sedatives, approximately half of the intensive care units assessed assumed GCS. There was variation in the methods used to assess the PaO2/FIO2 ratio. Standardized assessment methods for GCS and the PaO2/FIO2 ratio are needed to obtain valid SOFA score.

Surfactant-Assisted Synthesis of Pt Nanocubes Using Poly(N-isopropylacrylamide) Nanogels.

Poly(N-isopropylacrylamide) (PNIPAM) nanogels were prepared by emulsion polymerization using sodium dodecyl sulfate (SDS) and employed as a capping agent in platinum nanoparticle (Pt NP) synthesis by liquid-phase reduction with hydrogen gas. When the PNIPAM nanogels were used without removing SDS, that is, a slight amount of SDS was included in the reaction solution, Pt nanocubes (NCs) were predominantly produced (>80%). The proportion of the resultant Pt NCs was much higher than that obtained using the PNIPAM linear polymer (∼60%). To clarify the effects of the three-dimensional polymer network and SDS, we synthesized Pt NPs using the PNIPAM nanogel without SDS (SDS-free PNIPAM nanogel) and found that Pt NCs are rarely formed, and most NPs obtained have an irregular shape. When only SDS was used as a capping agent, NCs were hardly obtained, but other polyhedral NPs were formed. Furthermore, the use of SDS together with the PNIPAM polymer led to the decrease in the proportion of the Pt NCs compared with that obtained using only the linear polymer. These results indicate that the enhancement of the Pt NC proportion using the PNIPAM nanogel with SDS is attributable to not only the three-dimensional polymer network of the PNIPAM nanogel but also the assist of SDS as a capping agent.

Age-Related Differences in Strategy in the Hand Mental Rotation Task.

Mental imagery of movement is a potentially valuable rehabilitation task, but its therapeutic efficacy may depend on the specific cognitive strategy employed. Individuals use two main strategies to perform the hand mental rotation task (HMRT), which involves determining whether a visual image depicts a left or right hand. One is the motor imagery (MI) strategy, which involves mentally simulating one's own hand movements. In this case, task performance as measured by response time (RT) is subject to a medial-lateral effect wherein the RT is reduced when the fingertips are directed medially, presumably as the actual motion would be easier. The other strategy is to employ visual imagery (VI), which involves mentally rotating the picture and is not subject to this medial-lateral effect. The rehabilitative benefits of the HMRT are thought to depend on the MI strategy (mental practice), so it is essential to examine the effects of individual factors such as age, image perspective (e.g., palm or back of the hand), and innate ability (as indicated by baseline RT) on the strategy adopted. When presented with pictures of the palm, all subjects in the current study used the MI strategy, regardless of age and ability. In contrast, when subjects were presented with pictures of the back of the hand, the VI strategy predominated among the young age group regardless of performance, while the strategy used by middle-age and elderly groups depended on performance ability. In the middle-age and elderly groups, the VI approach predominated in those with high performance skill, whereas the MI strategy predominated among those with low performance skill. Thus, higher-skill middle-aged and elderly individuals may not necessarily form a motion image during the HMRT, potentially limiting rehabilitation efficacy.

Assessment of driving skills of a mobility scooter using driving operation logs.

A mobility scooter is a major assistive technology that replaces human ambulatory functions for people with disabilities. A license is often not required for driving a mobility scooter; therefore, less skilled drivers might create safety concerns. An effective way of reducing these safety risks is by assessing the driving skills of users. The existing assessment measures mostly score the task performance using manual observations. In this study, we have developed a novel assessment system that logs the driving operations by using add-on sensors. This system can monitor the operations of a mobility scooter including the angles of the throttle lever and the steering tiller. The subjects were seven older adults who participated in the driving test involving six tasks; the driver performances were video recorded, and the vehicle operation data were logged. The video analysis showed that two subjects crashed their scooters into objects or made contact with objects during the test course. To extract the characteristic patterns of the operations from the logs, 2D histograms of the operational status durations were investigated for each subject and task. Subsequent analysis of the operation logs identified the two subjects who had crashed their vehicles during the test drive. Our results proved that the driving operation logs could be used complementarily as a simple and low-cost tool for assessing a person's driving skills.

Adipose tissue-derived regenerative cells improve implantation of fertilized eggs in thin endometrium.

Aim: Embryo implantation and subsequent pregnancy depends on endometrial thickness. To investigate potential fertility strategies for women with thin endometrium, we explored the efficacy of adipose tissue-derived regenerative cells (ADRCs) on thin endometrium and embryo implantation in a mouse model. Materials & methods: ADRCs isolated from mouse subcutaneous fat were characterized by flow cytometry. Endometrium thickness, endometrial fibrosis, embryo implantation and angiogenesis factors were evaluated in uterine cavities of ethanol-induced thin endometrium mice with ADRC transplantation. Results: ADRCs included adipose-derived stem cells and some blood vessel component cells. ADRCs improved endometrial thickness, endometrial fibrosis and embryo implantation and augmented vascular endothelial growth factor expression in the mouse uterine. Conclusion: ADRCs may be a useful therapeutic strategy to improve fertility of women with thin endometrium.

Variation in Performance Strategies of a Hand Mental Rotation Task on Elderly.

A hand mental rotation task (HMRT) is a task wherein a person judges whether an image of a rotated hand is of the right or left hand. Two performance strategies are expected to come into play when performing these tasks: a visual imagery (VI) strategy, in which an image is mentally rotated, and a motor imagery (MI) strategy, in which the movement of a person's own hand is simulated. Although elderly people generally take some time to perform these tasks, ability differs greatly between individuals. The present study hypothesizes that there is a relationship between differences in task performance strategy and performance ability, and it compares performance strategy among elderly people divided into groups with a short mental rotation time and a long mental rotation time. In response to images of the palm, both groups displayed a medial-lateral effect in which responses were faster for images where the third finger was rotated toward the midline of the body than images rotated in the opposite direction, and we inferred that an MI strategy was primarily employed. Meanwhile, in response to images of the back of the hand, a medial-lateral effect was also observed in the group with a long mental rotation time and not in the group with the shortest mental rotation time (VI strategy). These results suggest that different strategies for performing HMRT task are used by elderly people with a short mental rotation time and those with a long mental rotation time.

Response time differences between men and women during hand mental rotation.

This study explored gender differences in correct response rates and response times on a task involving left or right arrow selection and another involving the transformation of mental rotation of the hand. We recruited 15 healthy, right-handed men (age 24.5 ± 6.4) and 15 healthy, right-handed women (age 21.3 ± 4.9). For the tasks, we used pictures of left and right arrows and 32 hand pictures (left and right, palm and back) placed in cons (each at 45° from 0° to 315°). Hand and arrow pictures alternated and were shown at random. Participants decided as quickly as possible whether each picture was left or right. To compare the time taken for the transformation of mental rotation of the hand, we subtracted the average arrow response time from that for the left and right hand pictures for each participant. Correct response rates did not differ significantly between men and women or left and right for either arrow or hand pictures. Regardless of gender, the response time was longer for the left arrow picture than right arrow picture. The response time for the hand picture was longest for both men and women for pictures at rotation angles that were most difficult to align with participants' hands. While there was no difference between men's responses for left and right hand pictures, the responses of women were longer for left than right hand pictures and also than those of men. These findings suggest that both men and women mainly perform the hand mental rotation task with implicit motor imagery. On the other hand, the gender difference in performance might be explained by the difference in balance with other strategies, such as visual imagery, and by cognitive, neurophysiological, and morphological differences.

Nimesulide, a cyclooxygenase-2 selective inhibitor, suppresses obesity-related non-alcoholic fatty liver disease and hepatic insulin resistance through the regulation of peroxisome proliferator-activated receptor γ.

Cyclooxygenase (COX)-2 selective inhibitors suppress non-alcoholic fatty liver disease (NAFLD); however, the precise mechanism of action remains unknown. The aim of this study was to examine how the COX-2 selective inhibitor nimesulide suppresses NAFLD in a murine model of high-fat diet (HFD)­induced obesity. Mice were fed either a normal chow diet (NC), an HFD, or HFD plus nimesulide (HFD-nime) for 12 weeks. Body weight, hepatic COX-2 mRNA expression and triglyceride accumulation were significantly increased in the HFD group. Triglyceride accumulation was suppressed in the HFD-nime group. The mRNA expression of hepatic peroxisome proliferator-activated receptor Î³ (PPARγ) and the natural PPARγ agonist 15-deoxy-Δ12,14-prostaglandin J2 (15d­PGJ2) were significantly increased in the HFD group and significantly suppressed in the HFD-nime group. Glucose metabolism was impaired in the HFD group compared with the NC group, and it was significantly improved in the HFD-nime group. In addition, the plasma insulin levels in the HFD group were increased compared with those in the NC group, and were decreased in the HFD-nime group. These results indicate that HFD-induced NAFLD is mediated by the increased hepatic expression of COX-2. We suggest that the production of 15d-PGJ2, which is mediated by COX-2, induces NAFLD and hepatic insulin resistance by activating PPARγ. Furthermore, the mRNA expression of tissue inhibitor of metalloproteinases-1 (TIMP­1), procollagen-1 and monocyte chemoattractant protein-1 (MCP-1), as well as the number of F4/80-positive hepatic (Kupffer) cells, were significantly increased in the HFD group compared with the NC group, and they were reduced by nimesulide. In conclusion, COX-2 may emerge as a molecular target for preventing the development of NAFLD and insulin resistance in diet-related obesity.

VEGF secretion by adipose tissue-derived regenerative cells is impaired under hyperglycemic conditions via glucose transporter activation and ROS increase.

Transplantation of cultured adipose-derived regenerative cells (ADRCs) into ischemic tissues promotes neovascularization and blood perfusion recovery. These effects are attenuated in diabetes patients. We examined the effects of hyperglycemia on the angiogenic capacity of ADRCs derived from Wistar rats both in vivo and in vitro. Cultured ADRCs were predominantly composed of CD90 positive cells; prevalence of CD90 positive cells was not affected by hyperglycemia. mRNA and protein levels of vascular endothelial growth factor (VEGF) were significantly decreased in ADRCs under hyperglycemic conditions independent of osmolarity, whereas mRNA levels of hepatocyte growth factor and fibroblast growth factor were unaffected. Since ADRCs express glucose transporter proteins GLUT1, 3 and 4, we examined the effects of the glucose transporter inhibitor phloretin on reactive oxygen species (ROS) and angiogenic factors. Phloretin decreased the glucose uptake rate, reduced ROS, and increased VEGF mRNA in ADRCs exposed to a hyperglycemic condition. In vivo transplantation of ADRCs cultured under hyperglycemic conditions into mouse ischemic limbs resulted in significantly decreased blood perfusion and capillary density in ischemic regions compared with transplantation of ADRCs cultured under normoglycemic conditions. These results suggest that hyperglycemia impaired VEGF production in ADRCs via an increase of ROS, impairing the angiogenic capacity of ADRCs transplanted into ischemic limbs.

Disruption of a rice gene for α-glucan water dikinase, OsGWD1, leads to hyperaccumulation of starch in leaves but exhibits limited effects on growth.

To identify potential regulators of photoassimilate partitioning, we screened for rice mutant plants that accumulate high levels of starch in the leaf blades, and a mutant line leaf starch excess 1 (LSE1) was obtained and characterized. The starch content in the leaf blades of LSE1 was more than 10-fold higher than that in wild-type plants throughout the day, while the sucrose content was unaffected. The gene responsible for the LSE1 phenotype was identified by gene mapping to be a gene encoding α-glucan water dikinase, OsGWD1 (Os06g0498400), and a 3.4-kb deletion of the gene was found in the mutant plant. Despite the hyperaccumulation of starch in their leaf blades, LSE1 plants exhibited no significant change in vegetative growth, presenting a clear contrast to the reported mutants of Arabidopsis thaliana and Lotus japonicus in which disruption of the genes for α-glucan water dikinase leads to marked inhibition of vegetative growth. In reproductive growth, however, LSE1 exhibited fewer panicles per plant, lower percentage of ripened grains and smaller grains; consequently, the grain yield was lower in LSE1 plants than in wild-type plants by 20~40%. Collectively, although α-glucan water dikinase was suggested to have universal importance in leaf starch degradation in higher plants, the physiological priority of leaf starch in photoassimilate allocation may vary among plant species.

Transplantation of freshly isolated adipose tissue-derived regenerative cells enhances angiogenesis in a murine model of hind limb ischemia.

Therapeutic angiogenesis has emerged as one of the most promising therapies for severe ischemic cardiovascular diseases with no optional therapy. Several investigators have reported that transplantation of cultured adipose-derived regenerative cells (cADRCs) to ischemic tissues promotes neovascularization and blood perfusion recovery; however, cell therapy using cultured cells has several restrictions. To resolve this problem, the angiogenic capacity of freshly isolated ADRCs (fADRCs) obtained from Lewis rats was compared with cADRCs, both in vivo and in vitro. Flow cytometric analysis showed that fADRCs contained several cell types such as endothelial progenitor cells and endothelial cells; however, these cells were present in a very small proportion in cADRCs. Transplantation of fADRCs in mice significantly improved blood perfusion, capillary density, and production of several angiogenic factors in transplanted ischemic limbs compared with a saline-injected group, whereas these effects were not observed in the cADRCs-injected group. fADRCs also showed significantly higher expression levels of angiogenic factors than cADRCs in the in vitro study. Furthermore, fADRC stimulated tube formation more remarkably than cADRC in an in vitro tube formation assay. These results suggested that fADRCs have an effective angiogenic capacity, and they would be more valuable as a source for cell-based therapeutic angiogenesis than cADRCs or other stem/progenitor cells.

Chemiluminescence from singlet oxygen that was detected at two wavelengths and effects of biomolecules on it.

We developed the detection apparatus that equipped with the two-photomultiplier tubes for chemiluminescence from singlet oxygen. Singlet oxygen was generated with reaction between sodium hypochlorite and hydrogen peroxide. The chemiluminescence from singlet oxygen, the dimol light emission (ca. 634 nm) and the monomol light emission (ca. 1270 nm), was observed simultaneously for the same reaction cell. The effects of sodium azide as an antioxidant, human serum albumin, and alpha-amino acids on the chemiluminescence based on the both emissions were examined; the observed chemiluminescence could provide direct information with regard to the reaction between singlet oxygen and antioxidant/biomolecules. The apparent rate constants for quenching singlet oxygen in the presence of human serum albumin were calculated to be ca. 3.3 x 10(9) and ca. 8.8 x 10(8)M(-1)s(-1) for the dimol and monomol light emissions, respectively, under the present conditions. The chemiluminescence intensities of the dimol emission decreased in the presence of His, Asp, Phe, Ser, and Tyr, and that of the monomol decreased in the presence of Cys and Trp. The chemiluminescence observed in the presence of biomolcules was discussed together with the reactivities of sodium hypochlorite and hydrogen peroxide to biomolecules.