Nucleating and reinforcing effects of nanobiochar on poly(3-hydroxybutyrate-co-3-hydroxhexanoate) bionanocomposites.

This study promotes the use of nanobiochar (NBC) as an environmentally friendly substitute to conventional fillers to improve various properties of biopolymers such as their mechanical strength, thermal stability and crystallization properties. TGA analysis showed a slight increase in onset thermal degradation temperature of the composites by up to 5 °C with the addition of 4 wt% NBC. Non-isothermal DSC analysis determined that the addition of NBC into PHBHHx increases the crystallization temperature and degree of crystallinity of PHBHHx while isothermal DSC analysis demonstrated higher crystallization rate in PHBHHx/NBC composited by up to 54%. PHBHHx incorporated with NBC also exhibited superior tensile strength and modulus versus neat PHBHHx. Increase in mechanical strength was further proven via DMA where PHBHHx/NBC composites maintained higher storage modulus at higher temperatures when compared to neat PHBHHx. PHBHHx/NBC also exhibited no cytotoxicity effect against HaCat cells. This study demonstrates the ability of biochar to act as both nucleating agents and reinforcing agents in biodegradable polymers such as PHBHHx, which could be suitable for packaging application.

The relationship between physical therapy clinical educator's motivation and negative factors.

[Purpose] The purpose of this study was to clarify the relationship between physical therapy clinical educators' motivations and negative personal factors. [Participants and Methods] The authors sent a questionnaire on clinical education to 790 physical therapists working in hospitals across Japan, and received 345 valid responses. The study defined motivated and unmotivated clinical educators based on their answers to the "interests" and "enjoyment" aspects of clinical education. It also calculated the negative response rate out of 10 questions and odds ratio based on motivated clinical educators. [Results] The motivated group comprised 287 clinical educators (years of clinical experience: 8.1 ± 6.3) and the unmotivated group 58 (years of clinical experience: 7.0 ± 5.2). There was no statistically significant difference in years of clinical experience between the two groups. Two questions-"Is student guidance necessary for growth as a therapist (self-improvement)?" and "Do you want to learn about instructional methods?"-showed very high odds ratios. [Conclusion] This study reveals negative personal factors for the clinical educators who lack the will to educate students, such as preparation for clinical education, self-improvement, and cooperation with class instructors. Longitudinal research on motivated and unmotivated clinical educators will help identify these negative factors to improve their motivation.

The evaluation of oral health in stroke patients.

OBJECTIVE: As tooth loss has been suggested as a potential risk factor for stroke, oral examinations were carried out on stroke patients to review the oral condition of those patients. METHOD: The subjects were patients consecutively discharged from the recovery rehabilitation unit of Hiroshima City General Rehabilitation Center between April 2008 and December 2009. All patients were offered oral examination and 358 of 443 patients accepted. Patients receiving dental examination were divided into two groups: one group comprising stroke patients and the second, patients with other disorders. These two groups were then compared for the number of remaining teeth by age group. RESULTS: Among the examined patients, the number of remaining teeth in stroke patients in their 50s and 60s was significantly lower than for patients in corresponding age groups (18.4 ± 9.4 vs. 24.5 ± 5.4 and 18.3 ± 9.2 vs. 22.2 ± 7.2, respectively, with p < 0.05 for both age groups) who were hospitalised for other conditions. In addition, the number of remaining teeth in stroke patients in their 50s was also significantly lower than the number reported in the Survey of Dental Diseases (24.1 ± 6.1; p < 0.05). CONCLUSION: The results of this study suggest an association between tooth loss and early occurrence of stroke.

Effect of long-term, community-based daily exercise on the ability to control the dynamic standing balance of Japanese elderly persons in relation to falls.

It is widely accepted that daily exercise improves the dynamic standing balance of elderly persons. In the current study, 77 community-dwelling Japanese elderly persons (aged 71.1 +/- 0.5 years) participated in a daily exercise program to assess its effect on their dynamic standing balance. The daily exercise consisted of walking, stretching, muscle strengthening, and balance exercises. The program ran for 31 months and the dynamic standing balance was assessed at the start of the program and again at 3, 7, 12, 19, 24, and 31 months. In most of the tests of dynamic standing balance, the measured values improved drastically in the first 7 months; thereafter, they either reached a plateau or continued to improve more slowly. These findings can contribute to the future planning of community-based exercise programs; in particular, the length of the program and the timing of changes to the exercise load.

The neural adjustment of postural response through community-based daily exercises in elderly persons.

BACKGROUND: Reflecting the rapidly aging population, community-based interventions in the form of physical exercise have been introduced to promote the health of elderly persons and prevent falls. Postural response is the critical neural response for preventing falls. The objective of this study was to assess the effect of long-term daily exercise on neural adjustment in postural response elucidated by sudden postural perturbation. METHODS: Twenty-six community-based elderly persons (13 men and women; 69.8+/-0.5 years old) participated in this study. Daily exercise was composed of walking for longer than 30 min, stretching, muscle strengthening and balance exercise, and was continued for 3 months. Postural responses were induced by fore or aft horizontal displacement of a platform with a force plate. Center of pressure on the force plate and electromyography of the rectus femoris, tibia anterior, biceps femoris and gastrocnemius were measured in postural response. FINDINGS: Following the 3 months of physical intervention, the amplitude and timing of the center of pressure excursion did not change, whereas the amplitude of muscular activities of the lower leg muscles required for the response significantly decreased. Furthermore, the onset of muscular activation of the lower leg muscles was significantly shortened following the intervention. INTERPRETATION: In conclusion, we showed that a program composed of 3 months of comprehensive exercise modulated the output of the postural response through a neural adjustment in the timing and amplitude of the muscular activation.

The effects of comprehensive exercise program on the adjustments of standing balance in community-dwelling elderly persons.

The objective of this study was to assess the effect of comprehensive exercise program widely accepted as a community-based physical intervention for the prevention of falling in the elderly persons on their controlling standing balance. Twenty-six community-dwelling elderly persons (13 males and females; 69.8 ± 2.8 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise without exercise equipments. The intervention was continued for three months. Indicators of standing balance related to static balance, dynamic balance and postural response were measured before and after the intervention. As an effect of the intervention on static balance, the sway of center of pressure (COP) in the static stance significantly increased. In the dynamic balance, significant improvements were observed in one leg standing time, the 10-m gait time, functional reach. Additionally, the maximal movable length of COP which subjects can move voluntarily to right and left significantly increased. In the postural response, the integrated electromyography (IEMG) induced by postural response for sudden postural perturbation significantly decreased in the lower leg muscles. Since less muscular activities were sufficient to maintain posture, it was suggested that postural response was elicited more efficiently following the intervention. This study suggested that the comprehensive exercise program, which has been widely introduced as community-based interventions for the prevention of falling, have extensive effects on the control of standing balance covering static balance, dynamic balance and postural response in the elderly persons.

Alteration of knee joint connective tissues during contracture formation in spastic rats after an experimentally induced spinal cord injury.

This study was made to elucidate the changes in the periarticular connective tissue that can underlie the contracture after spasticity development. Sixteen Wistar rats underwent a spinal cord injury and 16 rats were either sham- or nonoperated. The periarticular connective tissue of the knee joint was assessed with histological, histomorphometric, immunohistochemical, and biochemical analyses. Histological results showed a smaller synovial intima, a dense subintimal and posterior joint capsule without fibrosis, and a disarranged posterior capsule in the spinal cord-injured knees with the flexion contracture. The synovial intima length was shortened only at the posterior capsule. Neither the distribution nor expression of type I and III collagen was affected. Contractures after spinal cord injuries are characterized by synovial intima adhesions. A dense and disarranged capsule may lead to joint stiffness. The alteration of periarticular connective tissues exhibits properties characteristic of the contracture after spasticity development.

[Epidemiological survey of pneumococcus serotypes in pediatric patients with acute suppurative otitis media].

To determine the distribution of Streptococcus pneumoniae serotypes isolated from patients under 6 years of age with acute suppurative otitis media, to calculate the serotype coverage of 7-valent pneumococcal conjugate vaccine, and to clarify trends in PCG-resistant Streptococcus pneumoniae, we conducted a one-year prospective study from April 2005 to March 2006 at 10 medical institutions in Hokkaido, Miyagi, Chiba, Tokyo, Kanagawa, and Mie, Japan. Specimens collected by tympanotomy or myringotomy numbered 856, and 691 strains were isolated from 599 specimens. Of these, 219 isolates (31.7%) were identified as Streptococcus pneumoniae and 201 met study requirements. The most common serotype was 19F (52 isolates, 25.9%), followed by 6B (30 isolates, 14.9%) and 23F (24 isolates, 11.9%). Seven-valent vaccine serotype coverage was 62.7%. The percentage of PSSP was 40.3%, PISP 42.8%, and PRSP 16.9%, resistant strains (PISP and PRSP) combined accounted for 59.7%. Seven-valent vaccine serotype coverage for PISP was 80.2% and PRSP 82.4%. PBP gene mutation was observed in 175 isolates (87.1%), including 70 of gPISP (34.8%) and 105 of gPRSP (52.2%). Gene mutation induced by macrolides was found in 176 isolates (87.6%).

Neural adjustment in the activation of the lower leg muscles through daily physical exercises in community-based elderly persons.

Reflecting the rapidly aging population, community-based interventions in the form of physical exercise have been introduced to promote the health of elderly persons. Many investigation studies have focused on muscle strength in the lower leg as a potent indicator of the effect of physical exercises. The objective of this study was to assess the effect of long-term daily exercises on neural command in lower leg muscle activations. Twenty-six community-based elderly persons (13 men and 13 women; 69.8 +/- 0.5 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise, and was continued for three months. Muscle strength and surface electromyography of the tibia anterior, rectus femoris, and biceps femoris were measured in maximum isometric voluntary contraction both before and after the intervention. The mean frequency of the firing of motor units was calculated based on fast Fourier transformation of the electromyography. As the results of the intervention, muscle strength increased significantly only in biceps femoris, whereas the mean frequency of motor units decreased significantly in every muscle, indicating that motor unit firing in lower frequency efficiently induces the same or greater strength compared with before the intervention. Thus, synchronization of motor units compensates for the lower frequency of motor unit firing to maintain muscular strength. In conclusion, long-term physical exercises in the elderly can modulate the neural adjustment of lower leg muscles to promote efficient output of muscle strength.

The mRNA expression of neurotrophins in different skeletal muscles of young rats.

Skeletal muscles are a target for motoneurons and synthesize neurotrophins, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). Both at the embryonic stage and the adult stage, the mRNA expression of neurotrophins in skeletal muscles of rats has been reported. However, little was known about the mRNA expression patterns of neurotrophins in skeletal muscles of rats at the young developmental stage. In this study, we investigated the mRNA expressions of BDNF and NT-3 in three different skeletal muscles in 4- to 8- week-old rats using the reverse transcriptional polymerase chain reaction (RT-PCR) method. The expression of BDNF mRNA in the soleus muscle gradually became higher with age from 5 to 8 weeks. But BDNF mRNA in the tibialis anterior and extensor digitorum longus muscles did not change with growth. The expression of NT-3 mRNA did not show a specific tendency during this period. The differences of muscle fiber types, recruitment patterns of the muscles, and roles of neurotrophins may cause these mRNA expression patterns. Neurotrophins are target-derived, activity-dependent neurotrophic factors and are transported retrogradely. There is a possibility that the different expression patterns of neurotrophins in muscles may be involved in the maturation of neuromuscular function in different muscles during the young developmental period.

The progression of bone and muscle atrophy in mice hind limb with immobilization.

This study investigated the time course of changes of bone and muscle atrophy in mice with immobilization by denervation and fixation. The animals were fifty-two male C57 BL/6J mice, aged 10 weeks old. Eight mice were used as the base line, and the remaining ones were cut at the sciatic nerve of the left hind limb and fixed with a plaster cast. At week 1, 2, 3, and 4 after the operation, a cross-sectional area of the rectus femoris muscles and bone mechanical strength with a three-point bending test of the femur and tibia were measured. The time course of changes of the bone mechanical strength and of the cross-sectional area of the rectus femoris muscles between the intact and experimental limbs in each period compared with the control limbs, was determined. The bone mechanical strength of the femur, tibia, and the cross-sectional area of the rectus femoris muscles of the experimental limbs significantly decreased compared with those of the intact limbs at week 4, 3, 2 and 1 after the operation (p<0.05). Compared with the intact limbs, the bone mechanical strength and the cross-sectional area of the rectus femoris muscles of the experimental limbs declined approximately 10% and 30%, respectively, during the experiment (p<0.05). It was demonstrated that bone and muscle atrophy occurred at an early stage after immobilization by denervation and fixation, and that both types of atrophy progressed simultaneously in the present study.

Progression and direction of contractures of knee joints following spinal cord injury in the rat.

Joint contractures following central nervous system injuries remain a prevalent and significant complication, but no reports are available on evidence of contracture formation over time. The objective of this study was to determine the rate of contracture progression and the direction of loss in joint movement following spinal cord injuries (SCI). Forty-eight female Wistar rats were used. Twenty-four experimental rats underwent a spinal cord transection at the level of T8 and 24 control rats underwent a sham-operation. The animals were studied at each of 5 time points: 2, 4, 8, 12, 16, and 24 weeks after surgical intervention. The degree of contractures was assessed by measuring the femorotibial angle on both hindlimbs with the use of a goniometer. Knee joint motion was measured for flexion and extension direction. Knee flexion contractures developed in all experimental rats. The restriction in motion progressed during the first 12 weeks and plateaued thereafter. The contractures were produced almost exclusively by a loss in the extension range of motion. This study defined the time course that contracture progression was more rapid in the early stage after SCI and stabilized in the later stage of injury. Contractures following SCI occurred in flexion at the knees and resulted from a loss of extension. These findings should help guide timely treatment and provide a better understanding of contracture development.

The Relationship between Postural Deformation and Standing Balance in Elderly Person.

Falling due to unstable standing balance is considered to be the main cause of bone fractures, which lead elderly persons to becoming bedridden. Thus, the standing balance of elderly persons is being given increasingly greater attention. On the other hand, postural deformation caused by deformation in the spine and lower leg joints is considered to have an effect on standing balance. The objective of this study is to clarify the effect of postural deformation on the following three categories of standing balance; 1) the ability to immobilize Center of Gravity (COG) in standing statically, 2) the ability to control COG during movement and 3) the postural response induced by postural sway. Fifty elderly persons (age:77.7 ± 6.4 years old, fifty females) participated in this study. Postural deformation was measured using a Spinal Mouse, a device for non-invasive measurement of spinal curvature and photographic image in sagittal plane. In line with to Nakata's classification of postural deformation, subjects were classified by extension type, S-character deformation type, flexion type, hands on the knee type and normal group. In order to assess the ability to immobilize COG in static standing, Center of Pressure (COP) in static standing was measured for 30 sec. In order to assess the ability to control COG during movement, functional reach, maximal length of stride and the period of 10 m gait were measured. Postural response was induced by fore-aft perturbation of the platform on which the subjects stood. Postural responses were assessed by measuring both COP, and electromyography (EMG) of muscles in the lower legs. There was little significant difference among the five groups concerning postural deformation in every measured item, neither in the ability to immobilize COP in static standing, nor in the postural response induced by postural sway. However, the results of measured items concerning the ability to control COG during movement were significantly worse in flexion type and hands on the knee type compared with the normal group. It was suggested that postural deformation in elderly persons effects exclusively on the ability to control COG during movement in standing balance.

Change of bone mechanical strength in rats after spinal cord injury over a short term.

This study investigated the time-course of changes in bone mechanical strength in rats with spinal cord injury (SCI). Sixty-four male Wistar rats underwent spinal cord transection at the thoracic nerve. Control rats underwent a sham procedure (SHAM). Animals were sacrificed at day 1, 4, 7 and 14 after operation. The mechanical strength of the left femur and tibia was measured by the three-point bending strength test. The bones were dried, weighed and burned to ash. A specimen of right tibia was prepared and examined under a microscope. Bone mechanical strength, dry bone weight, and ash content of the femur and tibia in SCI rats were significantly lower than those in SHAM animals. Dry bone weight and ash content began to decrease from the 4th day after SCI and reached their lowest at day 7 after operation. Bone mechanical strength had reduced significantly by the 14th day. Gaps and spaces were observed in the trabecular area at the same time. After SCI, calcified cartilage decreased and the reduction of bone mass occurred rapidly. Moreover, a decline of bone mechanical strength is caused within 2 weeks. Thus, SCI led to the atrophy of bone and caused the reduction of mechanical strength at an early stage. It is thus necessary to prevent bone loss after SCI immediately.