Soichiro Hirata

The harmonic ratio of trunk acceleration predicts falling among older people: results of a 1-year prospective study

BackgroundGait variables derived from trunk accelerometry may predict the risk of falls; however, their associations with falls are not fully understood. The purpose of the study was to determine which gait variables derived from upper and lower trunk accelerometry are associated with the incidence of falls, and to compare the discriminative ability of gait variables and physical performance.MethodsThis study was a 1-year prospective study. Older people (n = 73) walked normally while wearing accelerometers attached to the upper and lower trunk. Participants were classified as fallers (n = 16) or non-fallers (n = 57) based on the incidence of falls over 1 year. The harmonic ratio (HR) of the upper and lower trunk was measured. Physical performance was measured in five chair stands and in the timed up and go test.ResultsThe HR of the upper and lower trunk were consistently lower in fallers than non-fallers (P < 0.05). Upper trunk HR, was independently associated with the incidence of falls (P < 0.05) after adjusting for confounding factors including physical performances. Consequently, upper trunk HR showed high discrimination for the risk of falls (AUC = 0.81).ConclusionsHR derived from upper trunk accelerometry may predict the risk of falls, independently of physical performance. The discriminative ability of HR for the risk of falls may have some validity, and further studies are needed to confirm the clinical relevance of trunk HR.

Reliability and validity of the Baecke physical activity questionnaire in adult women with hip disorders.

BackgroundAlthough physical activity maintenance is important for OA management, it is not clear whether people with OA are more inactive or not. One possible reason is no simple monitoring tool to assess physical activity at the clinic. The aim of this study was to determine the reliability and validity of the Baecke Physical Activity Questionnaire (BQ) in adult women with hip disorders.MethodsSixty-four patients with unilateral or bilateral hip disorders were recruited from an outpatients clinic at a university hospital in Japan. BQ includes a total of 16 questions classified into three domains: work, sports, and non-sports leisure activity. For test-retest reliability, one BQ was administrated face-to-face, and a second was mailed to participants two weeks later. Test-retest reliability of BQ was assessed using intra-class correlation (ICC) and Bland and Altman method. To determine criterion validity, the correlation between BQ measurements and pedometer-measured step counts was assessed. Correlations between BQ measurements and step counts were assessed using Spearman rank correlation coefficient (rho).ResultsAnalyses were restricted to the 61 patients (53.3 ± 11.3 years old) who wore the pedometer continuously for 5 days or more. Twenty eight patients had unilateral hip osteoarthritis, 17 patients had unilateral total hip arthroplasty, and 16 patients had hip osteoarthritis and total hip arthroplasty. The mean step count was 6,309 ± 2,392 steps/day. In analysis for reliability, the value of ICC was 0.84 for work, 0.83 for sports, 0.78 for non-sports leisure activity, and 0.87 total. Bland and Altman analysis showed the step count and BQ total did not differ significantly from 0 with most falling between 0 ± 1.96 SD. In analysis for validity, there was a significant but low to moderate correlation between step counts and 3 BQ subscales (rho, 0.30–0.49) and a higher correlation between step counts and total score (rho, 0.49).ConclusionBQ is a useful monitoring tool for assessing multiple domains of physical activity with acceptable reliability and validity in adult women with hip disorders.

Congenital pseudarthrosis of the clavicle : histologic examination for the etiology of the disease

The etiology of congenital pseudarthrosis of the clavicle remains obscure. The authors treated a 5-year-old boy with this rare disease. Clinical history and radiographs confirmed the diagnosis. Surgical treatment of resection of the pseudarthrosis, autologous bone graft, and internal fixation with a small AO plate led to successful bone union. Histologic analysis of the pseudarthrosis showed that there were cartilaginous caps on the proximal and distal bony ends. The appearance of the cartilaginous caps were equivalent to that of developing physes. They were adding new bone to the bony ends, which also was confirmed by preoperative tetracycline labeling. These observations support the hypothesis that the pseudarthrosis is caused by failure of 2 ossification centers to fuse, as was previously proposed by others.

Dual tasking affects lateral trunk control in healthy younger and older adults.

Assessing the effects of attention-demanding tasks on trunk movement provides useful insights into postural control while walking in an attention-split situation, such as occurs in daily life. The coefficient of attenuation of acceleration (CoA) at the trunk is a useful gait index to assess whole trunk movements. We investigated the effect of attention-demanding tasks on CoA to assess the role of attention on trunk control during walking. Thirty healthy, community-dwelling older adults (70.1±5.6 years) and 38 younger adults (22.1±3.4 years) participated in this study. Participants walked 20 m at a self-selected speed (slow, normal, fast) and while performing an attention-demanding cognitive task. Trunk acceleration was measured using triaxial accelerometers attached to the lower (L3 spinous process) and upper (C7 spinous process) trunk and used to compute CoA (the reduction in acceleration from the lower to upper trunk). Results showed that an attention-demanding task significantly decreased CoA in the medio-lateral (ML) direction in both age groups (p<0.001), whereas it did not affect CoA in the vertical (VT) and anterior-posterior (AP) directions. Our findings suggest that the priority of whole trunk control in the ML direction may be higher than in other directions and be strongly associated with attention, whereas whole trunk control in the VT and AP directions may be passively regulated and require minimal attentional control.

Bilateral pedicle stress fracture in a patient with osteoporotic compression fracture.

A case of bilateral pedicle stress fracture of L4 in a patient with osteoporotic compression fracture of L5 and without a history of major trauma or surgery is reported, and the literature is reviewed. Bilateral pedicle fracture is a rare entity and few cases have been reported in the literature. All reported cases had some underlying causative factors like previous spine surgery or stress related activities. To the best of the authors’ knowledge, only one case of bilateral pedicle stress fracture without a history of trauma, previous spine surgery, or stress-related activities has been reported. A 77-year-old woman presented with severe low back pain and radiating pain in the right leg that was exacerbated after standing and walking. Plain radiograph showed pathological fracture at L5 level. Magnetic resonance imaging (MRI) revealed the compression of dural sac at L5 level. CT scan taken 3xa0months after admission revealed bilateral pedicle fractures through L4. The patient was treated with decompressive laminectomies of L4, followed by posterior spinal fusion with rigid pedicle screw fixation and autogenous bone graft mixed with hydroxyapatite. The patient achieved pain relief and returned to normal activity. Stress fracture of the pedicle within the proximal vertebra of an osteoporotic compression fracture of lumbar spine is an uncommon entity. It may, however, be an additional source of symptoms in patients with osteoporosis who present with further back pain. Surgeons caring for this group of patients should be aware of this condition.

Apoptosis of hypertrophic chondrocytes in rat cartilaginous growth plate

Calcifying cartilages undergo endochondral ossification, a process in which cartilage is replaced by bone. These tissues contain chondrocytes that proliferate, leading, to differentiation and hypertrophy. Recent histological and biochemical studies suggest that hypertrophic chondrocytes undergo apoptosis. We investigated the process of this cell death to determine when fragmentation of DNA, a hallmark of apoptosis, occurs during cellular commitment to hypertrophy, and to test the hypothesis that the chondrocytes are intrinsically programmed to undergo apoptosis. End-labeling of fragmented DNA of rat proximal tibiae revealed that a majority of hypertrophic cells bore fragmented DNA, indicating that apoptosis was in progress in this zone. In pelleted chondrocyte cultures isolated from, rat rib growth plates and employed in an in vitro model of a growth plate, hypertrophic cells were also positive for end-labeling. Gel electrophoresis of DNA isolated from the chondrocyte cultures at 1–3 weeks yielded the ladder formation characteristic of apoptosis. We conclude that the chondrocytes in the growth plate are programmed to self-annihilate by apoptosis and that the apoptotic process is closely associated with the commitment to hypertrophy.

Gut microbiome, metabolome, and allergic diseases

The number of patients with allergic and inflammatory disorders has been increasing during the past several decades. Accumulating evidence has refined our understanding of the relationship between allergic diseases and the gut microbiome. In addition, the gut microbiome is now known to produce both useful and harmful metabolites from dietary materials. These metabolites and bacterial components help to regulate host immune responses and potentially affect the development of allergic diseases. Here, we describe recent findings regarding the immunologic crosstalk between commensal bacteria and dietary components in the regulation of host immunity and the influence of this relationship on the development of allergic diseases.

Method for preparing DNA from feces in guanidine thiocyanate solution affects 16S rRNA-based profiling of human microbiota diversity

Metagenomic analysis based on the 16S rRNA gene is generally performed to examine the diversity and abundance of commensal bacteria in feces, which is now recognized to be associated with human health and diseases. Guanidine thiocyanate (GuSCN) solution is used as a less onerous way compared with a frozen method to transport and stock fecal samples at room temperature for DNA analysis; however, optimal methods to measure fecal bacterial composition in GuSCN solution remain to be investigated. Here, we examined the influence of various factors such as pretreatment (e.g., removing GuSCN solution and washing feces with phosphate-buffered saline (PBS) before mechanical lysis), fecal concentration in the GuSCN solution, storage time, and position of fecal subsampling on the 16S rRNA-based analysis of fecal bacteria in GuSCN solution. We found that pretreatment and fecal concentration affected the bacterial composition, and a little change was noted with subsampling position. Based on these results, we propose a basic protocol, including fecal sampling, sample storage, and DNA extraction, for the 16S rRNA-based analysis of bacterial composition in feces suspended in GuSCN solution.

Can the Ordered Multi-Stepping Over Hoop test be useful for predicting fallers among older people? A preliminary 1 year cohort study

Background and aimsTo prevent falls among older people, we developed a new fall-risk assessment, the “Ordered Multi-Stepping Over Hoop (OMO)” test. The aims of this study were preliminary: to investigate the association of the OMO with cognitive and physical function and to investigate whether the OMO could predict incidents of falling.MethodsFifty-nine community-dwelling older people (mean agexa0=xa088.0xa0±xa00.87, femalexa0=xa049) were recruited. We assessed cognitive and physical function including the OMO test at baseline and monitored the falls of participants during a 12-month follow-up period from the baseline. We investigated whether the OMO was associated with cognitive function, physical function, and incidents of falling. To investigate whether the OMO could predict incidents of falling, a receiver operating characteristic analysis was conducted.ResultsThe OMO time in fallers was significantly slower than for non-fallers. There were significant correlations between slower OMO times and lower physical functions and executive function. The area under the ROC curve in the OMO was 0.71 (pxa0<xa00.05). Times above 21.9xa0s for the OMO identified those more likely to fall.ConclusionsThe OMO time was correlated with cognitive function, physical function, and incidents of falling. Our preliminary study indicates that the OMO may help to make a distinction between fallers and non-fallers among older people as effectively as other tests.

Development of a bivalent food poisoning vaccine: augmented antigenicity of the C-terminus of Clostridium perfringens enterotoxin by fusion with the B subunit of Escherichia coli Shiga toxin 2

Food poisonings caused by Clostridium perfringens and Shiga toxin (Stx)-producing Escherichia coli (STEC) occur frequently worldwide; however, no vaccine is currently available. Therefore, we aimed to develop a bivalent vaccine against C. perfringens and STEC infections. Although it has been considered that the C-terminal region of C. perfringens enterotoxin (C-CPE) could be a good vaccine antigen to block the binding to its receptor, it was insufficient for induction of a protective immune response because of the low antigenicity. However, the fusion of C-CPE with Stx2 B subunit (Stx2B) augmented the antigenicity of C-CPE without affecting the antigenicity of Stx2B. Indeed, high levels of C-CPE-specific neutralizing IgG were found in the serum of mice immunized with the fusion protein Stx2B-C-CPE. Additionally, comparable and substantial levels of Stx2B-specific neutralizing IgG were induced in mice receiving Stx2B-C-CPE or Stx2B alone. These antibody responses against C-CPE and Stx2B lasted for at least 48 weeks, which were sufficient for protective immunity in vitro and in vivo, indicating that Stx2B-C-CPE could induce long-term protective immunity. As an underlying mechanism, ex vivo stimulation with Stx2B, but not with C-CPE, induced cytokine production from splenic T cells collected from mice immunized with Stx2B-C-CPE, suggesting that Stx2B-specific, but not C-CPE-specific, T cells were induced by the immunization with Stx2B-C-CPE and plausibly promoted immunoglobulin class switching of both Stx2B- and C-CPE-specific B cells from IgM to IgG. These findings collectively indicate that Stx2B-C-CPE is a T-cell-antigen-supplement-type bivalent vaccine, which could be an efficient against C. perfringens and STEC infections.