The action of coenzyme B12-dependent diol dehydratase on 3,3,3-trifluoro-1,2-propanediol results in elimination of all the fluorides with formation of acetaldehyde.

3,3,3-Trifluoro-1,2-propanediol undergoes complete defluorination in two distinct steps: first, the conversion into 3,3,3-trifluoropropionaldehyde catalyzed by adenosylcobalamin (coenzyme B12)-dependent diol dehydratase; second, non-enzymatic elimination of all three fluorides from this aldehyde to afford malonic semialdehyde (3-oxopropanoic acid), which is decarboxylated to acetaldehyde. Diol dehydratase accepts 3,3,3-trifluoro-1,2-propanediol as a relatively poor substrate, albeit without significant mechanism-based inactivation of the enzyme during catalysis. Optical and EPR spectra revealed the steady-state formation of cob(II)alamin and a substrate-derived intermediate organic radical (3,3,3-trifluoro-1,2-dihydroxyprop-1-yl). The coenzyme undergoes Co-C bond homolysis initiating a sequence of reaction by the generally accepted pathway via intermediate radicals. However, the greater steric size of trifluoromethyl and especially its negative impact on the stability of an adjacent radical center compared to a methyl group has implications for the mechanism of the diol dehydratase reaction. Nevertheless, 3,3,3-trifluoropropionaldehyde is formed by the normal diol dehydratase pathway, but then undergoes non-enzymatic conversion into acetaldehyde, probably via 3,3-difluoropropenal and malonic semialdehyde.

Multiple-Community-Based Epidemiological Study of Stuttering among 3-Year-Old Children in Japan.

INTRODUCTION: Many epidemiological studies of the disorder of stuttering have been conducted during the 20th century, continuing during the current one. Unfortunately, only a few were carried out in Japan. This study aimed at assessing (1) the incidence and prevalence of stuttering in 3-year-old children in multiple Japanese communities and (2) factors associated with the onset of stuttering among these children. METHODS: A questionnaire aimed at screening for the presence of stuttering was employed for 2,055 children aged 3 years, who underwent a standard nationwide health checkup. Positive responses were confirmed in several ways: (1) direct interviews and assessment of the child's speech, (2) confirmatory questionnaire, or (3) telephone interviews by licensed Speech Language Hearing Therapists. RESULTS: Approximately 6.5% of the children were found to exhibit stuttering at the time of their health checkup. This figure rose to 8.9% after including individuals who previously, but not currently, were reported to have exhibited stuttering. Among the putative risk factors, higher stuttering odds (odds ratio, OR = 3.27) were detected in those with a family history of stuttering, those whose guardians had concerns about their child's development (OR = 1.75), and those with diagnosed diseases or disabilities (OR = 2.13). DISCUSSION/CONCLUSIONS: It was concluded that, in Japan, both the risk of stuttering incidence (8.9%) in children up to, and including, the age of 3 years, as well as its prevalence (6.5%) in this population, was similar to those reported by recent studies in other countries. Additionally, our findings also confirmed that an increased risk for stuttering at age 3 is associated with a family history of stuttering.

Effects of neoadjuvant chemotherapy for patients with obstructive colon cancer: A multicenter propensity score-matched analysis (YCOG2101).

Aim: Obstructive colon cancer is locally advanced colon cancer with poor prognosis. However, the effect of neoadjuvant chemotherapy (NAC) on obstructive colon cancer remains unclear. Therefore, this study aimed to investigate the safety and efficacy of NAC in patients with obstructive colon cancer. Methods: From January 2012 to December 2017, we collected patient data for clinical stage II/III obstructive colon cancer at seven Yokohama Clinical Oncology Group (YCOG) institutions. The long-term outcomes of the NAC and non-NAC groups were analyzed retrospectively after adjusting for patients' background characteristics using propensity score matching. Results: Among the 202 eligible patients, propensity score matching extracted 51 patients each for the NAC and non-NAC groups. After matching, the groups showed no marked differences in the background factors. All the patients in the NAC group underwent diverting stoma construction. Nineteen patients (37.3%) experienced grade 3-4 adverse events during NAC. The incidence of postoperative complications was similar between groups. The 5-year progression-free survival rates were 75.8% in the NAC group and 63.0% in the non-NAC group (p = 0.22, log-rank test). The 5-year overall survival rates were 88.5% in the NAC group and 78.8% in the non-NAC group (p = 0.09, log-rank test). Conclusion: Although NAC was feasible for obstructive colon cancer after diverting stoma construction, its effects on long-term outcomes could not be proven.

Usefulness of 3D-CT Angiography to Determine the Extent of Lymphadenectomy in Colon Cancer of the Splenic Flexure.

BACKGROUND/AIM: This study aimed to evaluate the extent of lymph node dissection (LND) determined using preoperative Three-dimensional computed tomographic angiography (3D-CTA), in the management of splenic flexure colon cancer (SFC). PATIENTS AND METHODS: In this retrospective, observational study, 61 patients who underwent preoperative 3D-CTA and laparoscopic complete mesocolic excision for SFC between December 2011 and December 2021 were identified at a tertiary care center in Japan. Preoperative 3D-CTA was used to confirm the feeding arteries, following which the extent of LND was determined. Left hemicolectomy was performed in cases requiring LND in the domains of the middle colic artery and left colic artery. In other cases, a partial colectomy (PC) that was defined as a segmental resection of the splenic flexure with LND in the domains of the feeding arteries was performed. Surgical and oncological outcomes were compared between PC and left hemicolectomy. RESULTS: Preoperative 3D-CTA enabled the evaluation of the feeding artery in all patients. PC was performed in 51 patients (83.6%). Patients who underwent PC had a shorter operative time (p=0.03) and less blood loss (p=0.01). There was no difference in complications between the two groups. There was also no significant difference in 5-year overall survival, nor 3-year disease free survival. CONCLUSION: Preoperative simulation using 3D-CTA has the potential to be useful in the identification of feeding arteries and determination of the oncologically adequate extent of LND for each patient.

Simulating Knee-Stress Distribution Using a Computed Tomography-Based Finite Element Model: A Case Study.

This study aimed to evaluate the mechanism of progression involved in knee osteoarthritis (OA). We used the computed tomography-based finite element method (CT-FEM) of quantitative X-ray CT imaging to calculate and create a model of the load response phase, wherein the greatest burden is placed on the knee joint while walking. Weight gain was simulated by asking a male individual with a normal gait to carry sandbags on both shoulders. We developed a CT-FEM model that incorporated walking characteristics of individuals. Upon simulating changes owing to a weight gain of approximately 20%, the equivalent stress increased extensively in both medial and lower leg aspects of the femur and increased medio-posteriorly by approximately 230%. As the varus angle increased, stress on the surface of the femoral cartilage did not change significantly. However, the equivalent stress on the surface of the subchondral femur was distributed over a wider area, increasing by approximately 170% in the medio-posterior direction. The range of equivalent stress affecting the lower-leg end of the knee joint widened, and stress on the posterior medial side also increased significantly. It was reconfirmed that weight gain and varus enhancement increase knee-joint stress and cause the progression of OA.

Reactivating chaperones for coenzyme B12-dependent diol and glycerol dehydratases and ethanolamine ammonia-lyase.

Adenosylcobalamin (AdoCbl) or coenzyme B12-dependent enzymes tend to undergo mechanism-based inactivation during catalysis or inactivation in the absence of substrate. Such inactivation may be inevitable because they use a highly reactive radical for catalysis, and side reactions of radical intermediates result in the damage of the coenzyme. How do living organisms address such inactivation when enzymes are inactivated by undesirable side reactions? We discovered reactivating factors for radical B12 eliminases. They function as releasing factors for damaged cofactor(s) from enzymes and thus mediate their exchange for intact AdoCbl. Since multiple turnovers and chaperone functions were demonstrated, they were renamed "reactivases" or "reactivating chaperones." They play an essential role in coenzyme recycling as part of the activity-maintaining systems for B12 enzymes. In this chapter, we describe our investigations on reactivating chaperones, including their discovery, gene cloning, preparation, characterization, activity assays, and mechanistic studies, that have been conducted using a wide range of biochemical and structural methods that we have developed.

Coenzyme B12-dependent eliminases: Diol and glycerol dehydratases and ethanolamine ammonia-lyase.

Adenosylcobalamin (AdoCbl) or coenzyme B12-dependent enzymes catalyze intramolecular group-transfer reactions and ribonucleotide reduction in a wide variety of organisms from bacteria to animals. They use a super-reactive primary-carbon radical formed by the homolysis of the coenzyme's Co-C bond for catalysis and thus belong to the larger class of "radical enzymes." For understanding the general mechanisms of radical enzymes, it is of great importance to establish the general mechanism of AdoCbl-dependent catalysis using enzymes that catalyze the simplest reactions-such as diol dehydratase, glycerol dehydratase and ethanolamine ammonia-lyase. These enzymes are often called "eliminases." We have studied AdoCbl and eliminases for more than a half century. Progress has always been driven by the development of new experimental methodologies. In this chapter, we describe our investigations on these enzymes, including their metabolic roles, gene cloning, preparation, characterization, activity assays, and mechanistic studies, that have been conducted using a wide range of biochemical and structural methodologies we have developed.

Plant-Growth-Promoting Effect by Cell Components of Purple Non-Sulfur Photosynthetic Bacteria.

Rhodobacter sphaeroides, a purple non-sulfur photosynthetic bacterium (PNSB), was disrupted by sonication and fractionated by centrifugation into the supernatant and pellet. The effects of the supernatant and pellet on plant growth were examined using Brassica rapa var. perviridis (komatsuna) in the pot experiments. Both fractions showed growth-promoting effects: the supernatant at high concentrations (1 × 107 to 4 × 107 cfu-equivalent mL-1) and the pellet at a low concentration of 2 × 103 cfu-equivalent mL-1). We expected lipopolysaccharide (LPS) to be the active principle of the pellet fraction and examined the effects of LPS on the growth of B. rapa var. perviridis. The growth of the plants was significantly enhanced by the foliar feeding of R. sphaeroides LPS at concentrations ranging from 10 to 100 pg mL-1. The present study is the first report indicating that LPS acts as one of the active principles of the plant-growth-promoting effect of PNSB.

Evaluation of vertebral bone strength with a finite element method using low dose computed tomography imaging.

BACKGROUND: Focusing on compression fractures of bone by finite elements, we evaluated bone strength based on the computed tomography-based finite element method. However, the exposure dose is an issue. We aimed to investigate the quantity of reduction of the radiation dose with respect to the reference dose by comparing the calculation results of compression fractures of the vertebral body using experimental data obtained from the spine of a pig. METHODS: Computed tomography images of a self-made phantom that enclosed the lower lumbar vertebra of edible wild pigs were obtained under baseline-dose conditions using various lower tube currents. Images obtained under reference-dose conditions were reconstructed using the filtered back-projection method, whereas images obtained under low-dose conditions were reconstructed using both the filtered back-projection method and the iterative reconstruction method. Computer simulations involving the creation of finite element models using all images were implemented for the compression load calculation for vertebral body parts. Based on the calculated results, images of the low-dose and reference-dose conditions were compared. RESULTS: Using pigs' lower lumbar vertebrae, finite element model analysis of low-dose X-ray computed tomography images showed that equivalent results can be obtained with a dose of approximately 40% of the standard radiographic reference doses. As for the compression stress intensity, the same results as those under reference-dose conditions were obtained using the iterative reconstruction method in combination with computed tomography-based finite element method. CONCLUSIONS: The combination of the iterative reconstruction method with the computed tomography-based finite element method is an effective image reconstruction method for achieving dose reduction.

Evaluation of an operation support system using the femoral anterior tangent line to determine intraoperative femoral component rotation in total knee arthroplasty.

BACKGROUND: The femoral anterior tangent (FAT) line refers to a line parallel to the anterior surface of the distal femur in the axial plane. This study aimed to evaluate the effectiveness of a new operation support system which uses the FAT line to set the femoral component rotational alignment in total knee arthroplasty (TKA). METHODS: A total of 170 consecutive knees in 139 patients undergoing primary TKA with the JIGEN (Jig Engaged Three-dimensional (3D) Pre-Operative Planning Software for TKA) operation support system was examined. The JIGEN system creates 3D models of bones using computed tomography data, allowing for surgical simulations such as positioning of implants while calculating positions of the intramedullary alignment rod (IM rod) and surgical jig. We retrospectively analyzed the FAT line angle relative to the surgical epicondylar axis (SEA) on the axis plane perpendicular to the IM rod and evaluated the accuracy of the femoral component alignment after TKA with the 3D measurement system. RESULTS: The FAT line was 9.6° ± 3.7° (range, 1.4°-20.4°) internally rotated relative to the SEA. The average absolute error was 1.4° ± 1.1° in the coronal plane, 2.0° ± 1.5° in the sagittal plane, and 1.6° ± 1.3° in the axial plane. The femoral component outliers (i.e., >3° away from the goal alignment) were 7.7% in the coronal plane, 20.6% in the sagittal plane, and 10.3% in the axial plane. CONCLUSIONS: Our findings suggest that the FAT line is a reliable and reproducibly identifiable axis for the accurate determination of proper rotational alignment in TKA. An operation support system which uses the FAT line for determining intraoperative femoral component rotation can effectively achieve highly accurate positioning of the femoral component in TKA.

Sway and Acceleration Changes of the Center of Mass during Walking Stance Phase before and after Total Knee Arthroplasty.

Elucidating the sway and changes in the acceleration of center of mass (COM) during walking is important for effective gait training and rehabilitation. The objective of this study was to verify the improvement in gait before and after total knee arthroplasty (TKA) from COM sway and the changes in the acceleration of COM during the stance phase of walking. This study included 13 patients (1 male and 12 females) with medial knee osteoarthritis who were hospitalized for TKA. The COM sway during the stance phase of walking was evaluated using root mean square (RMS) normalized by walking speed, and the changes in acceleration were further verified. Lateral and vertical RMS showed significant differences between preoperative and postoperative states and demonstrated low values after TKA. The lateral acceleration at the latter part of the early stance phase demonstrated a significant difference between preoperative and postoperative states. A significant difference was also observed in the lateral acceleration in the late stance phase between the two groups. Improvement in pain and alignment after TKA reduced the lateral sway of COM and the changes in acceleration during the gait stance phase, which is speculated to lead to improvement in gait and prevention of falls.

Necessity of Flanking Repeats R1' and R8' of Human Pumilio1 Protein for RNA Binding.

Human Pumilio (hPUM) is a structurally well-analyzed RNA-binding protein that has been used recently for artificial RNA binding. Structural analysis revealed that amino acids at positions 12, 13, and 16 in the repeats from R1 to R8 each contact one specific RNA base in the eight-nucleotide RNA target. The functions of the N- and C-terminal flanking repeats R1' and R8', however, remain unclear. Here, we report how the repeats contribute to overall RNA binding. We first prepared three mutants in which R1' and/or R8' were deleted and then analyzed RNA binding using gel shift assays. The assays showed that all deletion mutants bound to their target less than the original hPUM, but that R1' contributed more than R8', unlike Drosophila PUM. We next investigated which amino acid residues of R1' or R8' were responsible for RNA binding. With detailed analysis of the protein tertiary structure, we found a hydrophobic core in each of the repeats. We therefore mutated all hydrophobic amino residues in each core to alanine. The gel shift assays with the resulting mutants revealed that both hydrophobic cores contributed to the RNA binding: especially the hydrophobic core of R1' had a significant influence. In the present study, we demonstrated that the flanking R1' and R8' repeats are indispensable for RNA binding of hPUM and suggest that hydrophobic R1'-R1 interactions may stabilize the whole hPUM structure.

A Parkinson's disease patient displaying increased neuromelanin-sensitive areas in the substantia nigra after rehabilitation with tDCS: a case report.

Previous studies have reported that transcranial direct current stimulation (tDCS) of the frontal polar area (FPA) ameliorated motor disability in patients with Parkinson's disease (PD). Here we report changes in neuromelanin (NM) imaging of dopaminergic neurons before and after rehabilitation combined with anodal tDCS over the FPA for 2 weeks in a PD patient. After the intervention, the patient showed clinically meaningful improvements while the NM-sensitive area in the SN increased by 18.8%. This case study is the first report of NM imaging of the SN in a PD patient who received tDCS.Abbreviations FPA: front polar area; PD: Parkinson's disease; NM: neuromelanin; DCI: DOPA decarboxylase inhibitor; STEF: simple test for evaluating hand function; TUG: timed up and go test; TMT: trail-making test; SN: substantia nigra; NM-MRI: neuromelanin magnetic resonance imaging; MCID: the minimal clinically important difference; SNpc: substantia nigra pars compacta; VTA: ventral tegmental area; LC: locus coeruleus; PFC: prefrontal cortex; M1: primary motor cortex; MDS: Movement Disorder Society; MIBG: 123I-metaiodobenzylguanidine; SBR: specific binding ratio; SPECT: single-photon emission computed tomography; DAT: dopamine transporter; NIBS: noninvasive brain stimulation; tDCS: transcranial direct current stimulation; MAOB: monoamine oxidase B; DCI: decarboxylase inhibitor; repetitive transcranial magnetic stimulation: rTMS; diffusion tensor imaging: DTI; arterial spin labeling: ASL.

Genome sequence analysis of new plum pox virus isolates from Japan.

OBJECTIVE: To find mutations that may have recently occurred in Plum pox virus (PPV), we collected six PPV-infected plum/peach trees from the western part of Japan and one from the eastern part. After sequencing the full-length PPV genomic RNAs, we compared the amino acid sequences with representative isolates of each PPV strain. RESULTS: All new isolates were found to belong to the PPV-D strain: the six isolates collected from western Japan were identified as the West-Japan strain while the one collected from eastern Japan as the East-Japan strain. Amino acid sequence analysis of these seven isolates suggested that the 1407th and 1529th amino acid residues are characteristic of the West-Japan and the East-Japan strains, respectively. Comparing them with the corresponding amino acid residues of the 47 non-Japanese PPV-D isolates revealed that these amino acid residues are undoubtedly unique. A further examination of the relevant amino acid residues of the other 210 PPV-D isolates collected in Japan generated a new hypothesis regarding the invasion route from overseas and the subsequent diffusion route within Japan: a PPV-D strain might have invaded the western part of Japan from overseas and spread throughout Japan.

A Simulation Case Study of Knee Joint Compressive Stress during the Stance Phase in Severe Knee Osteoarthritis Using Finite Element Method.

Background and Objectives: Medial knee osteoarthritis is known to increase the mechanical load on the medial compartment of the knee joint during walking; however, it is not visually understood how much the mechanical load increases nor where in the medial compartment of the knee joint that load is focused. Therefore, we conducted a simulation study to determine the location and amount of the mechanical load in the medial compartment of the knee joint during the stance phase. Materials and Methods: Subject was a patient with right medial knee osteoarthritis. Computed tomography imaging and gait analysis were performed on subject. The CT image of the right knee was calculated using finite element analysis software. Since this software can set the flexion angle arbitrarily while maintaining the nonuniform material properties of the bone region, the model is constructed by matching the knee joint extension image obtained by CT to the loading response phase of gait analysis. The data of muscle exertion tension and vertical ground reaction force were inserted into the knee joint model created from the computed tomography-based finite element method, and the knee joint compressive stress was calculated. Results: With regard to compressive stress, the tibia showed high stress at 4.10 to 5.36 N/mm2. The femur showed high stress at 4.00 to 6.48 N/mm2. The joint compressive stress on the medial compartment of the knee joint was found to concentrate on the edge of the medial tibial condyle in the medial knee osteoarthritis subject. Conclusions: The measurement method of knee joint compressive stress by computed tomography-based finite element method can visually be a reliable method of measuring joint compressive stress in the medial knee osteoarthritis. This reflects the clinical findings because concentration of stress on the medial knee joint was observed at the medial osteophyte.

[Laparoscopic Gastrectomy for Gastric Cancer with Adachi Type â ¥ Vascular Anomaly-A Case Report].

We report a case of laparoscopic gastrectomy for gastric cancer with an anomalous celiac trunk categorized as Type Ⅵ- Group 24 in the Adachi classification. Upper gastrointestinal endoscopy in an 81-year-old male revealed a shallow depressed lesion in the middle of the gastric body. Close examination led to diagnosis of cT1bN0M0, cStage Ⅰ gastric cancer, and laparoscopic distal gastrectomy was planned. Contrast-enhanced CT revealed no anomalous bifurcation of the hepatic artery, but the common hepatic artery ran on the dorsal side of the portal vein, branching from the superior mesenteric artery. Therefore, an Adachi Type Ⅵ-Group 24 celiac trunk anomaly was diagnosed. During surgery, the common hepatic artery could not be confirmed in guiding suprapancreatic lymph node dissection, and the portal vein was exposed. Anterior to the portal vein, nerves that are usually around the common hepatic artery continuously ran toward the hepatoduodenal ligament instead. Suprapancreatic lymph nodes were dissected, with the portal vein considered as the common hepatic artery. Adachi Type Ⅵ is a rare anomaly with an incidence of about 2%. Preoperative diagnosis enables safe and appropriate lymph node dissection.

Optimal phase analysis of electrocardiogram-gated computed tomography angiography in patients with Stanford type A acute aortic dissection.

OBJECTIVE: To determine the phase that facilitates flap observation of the ascending aorta in Stanford type A acute aortic dissection with perfused false lumen. METHODS: We reconstructed retrospective Electrocardiogram-gated Computed Tomography Angiography images of the ascending aorta of all 20 patients to 20 phases of curved-multiplanar reconstruction in 5% increment. One radiologist created and randomized 10 cross-sectional images of each phase for every patient and two radiologists scored these images on a 5-point scale depending on the degree of flap stoppage. We calculated the average score for each phase of each case and compared them among the three groups. RESULTS: Image scores were significantly better in the 65 %-100 % R-R interval group than those in the 5%-30 % (p < 2e-16) and 35 %-60 % R-R interval groups(p = 7.2e-10). Similar scores were observed in the Heart Rate > 70 group (p = 0.00039, 2.2e-14). Moreover a similar tendency was observed in the arrhythmia group (p = 0.0035, 0.294). No difference was found in the degree of flap stoppage in the 65 %-100 % R-R interval group between the Heart Rate > 70 and Heart Rate ≤ 70 groups (p = 0.466) and between the arrhythmia and non-arrhythmia groups (p = 0.1240). CONCLUSION: In observing the ascending aorta, We obtained a good image at 65 %-100 % R-R interval and similar tendency was observed in the patients with arrhythmia.

Comparison of social anxiety between Japanese adults who stutter and non-stuttering controls.

PURPOSE: Adults who stutter (AWS) often develop social anxiety disorder. This study was to provide comparative data on the Liebowitz Social Anxiety Scale-Japanese version (LSAS-J) from AWS and non-stuttering adult controls. METHODS: LSAS-J, a 24-item self-reported survey of social phobia and avoidance across various daily situations, was administered to 130 AWS (Mean Age = 41.5 years, SD = 15.8, 111 males) and 114 non-stuttering adults (Mean Age = 39.5, SD = 14.9, 53 males). The test-retest reliability and internal consistency of the LSAS-J were assessed. A between-subject multivariate analysis of variance (MANOVA) was also conducted to determine whether attitude toward social anxiety differed between AWS and AWNS, or by age (<40 and ≥ 40 years old), or sex (female and male). RESULTS: AWS reported higher scores on both fear subscales of the LSAS-J. Age had no significant influence on the social anxiety levels reported by either participant group. Sex differences were found in the fear subscales, with females scoring higher on both fear subscales, although these were only marginally significant (p = .06). LSAS-J showed good test-retest reliability and high Cronbach's alpha coefficient, indicating that it is an internally consistent measure of attitudes about social anxiety. CONCLUSION: Given the similarly high incidence of social anxiety in adults in Japan who stutter compared with those in other countries, social anxiety should be identified and assessed during clinical decision making and before decisions are made about stuttering treatment. LSAS-J is an easy tool to administer, and showed reliable results of social phobia and avoidance for AWS.

Disfluencies and Strategies Used by People Who Stutter During a Working Memory Task.

Purpose Working memory (WM) deficits are implicated in various communication disorders, including stuttering. The reading span test (RST) measures WM capacity with the dual task of reading sentences aloud and remembering target words. This study demonstrates a difference in strategy between people who stutter (PWS) and people who do not stutter (PWNS) in performing the RST. The impact of the effective strategy and the stuttering-like disfluencies during the RST were investigated. Method Twenty-six PWS and 24 people who do not stutter performed the RST and a simple reading aloud task. After the RST, they were asked which strategy ("imagery" or "rehearsal") they had used in order to remember the target words during the task. Results The proportion of those who used an "imagery" strategy during the RST was significantly smaller in the PWS group. However, the RST scores of those who used an "imagery" strategy were significantly higher than the RST scores of those who used a "rehearsal" strategy in both groups. The "rehearsal" users were asked to undertake one more RST with an "imagery" strategy, which resulted in an increased score for both groups. The disfluency frequency of the PWS group was significantly reduced during the RST than during the oral reading task, irrespective of the employed strategy. Conclusions PWS tended to use the less effective verbal "rehearsal" strategy during the RST. The differential effects of switching strategies on the measured WM capacity and on the disfluency rate suggest that the enhanced fluency during the RST would be mostly attributable to the reduced attention to speech motor control. Therefore, the use of the "imagery" strategy and focusing on the contents of communication, away from speech motor control, should help PWS communicate better in daily conversation.

Development of a Knee Joint CT-FEM Model in Load Response of the Stance Phase During Walking Using Muscle Exertion, Motion Analysis, and Ground Reaction Force Data.

Background and objectives: There are no reports on articular stress distribution during walking based on any computed tomography (CT)-finite element model (CT-FEM). This study aimed to develop a calculation model of the load response (LR) phase, the most burdensome phase on the knee, during walking using the finite element method of quantitative CT images. Materials and Methods: The right knee of a 43-year-old man who had no history of osteoarthritis or surgeries of the knee was examined. An image of the knee was obtained using CT and the extension position image was converted to the flexion angle image in the LR phase. The bone was composed of heterogeneous materials. The ligaments were made of truss elements; therefore, they do not generate strain during expansion or contraction and do not affect the reaction force or pressure. The construction of the knee joint included material properties of the ligament, cartilage, and meniscus. The extensor and flexor muscles were calculated and set as the muscle exercise tension around the knee joint. Ground reaction force was vertically applied to suppress the rotation of the knee, and the thigh was restrained. Results: An FEM was constructed using a motion analyzer, floor reaction force meter, and muscle tractive force calculation. In a normal knee, the equivalent stress and joint contact reaction force in the LR phase were distributed over a wide area on the inner upper surface of the femur and tibia. Conclusions: We developed a calculation model in the LR phase of the knee joint during walking using a CT-FEM. Methods to evaluate the heteromorphic risk, mechanisms of transformation, prevention of knee osteoarthritis, and treatment may be developed using this model.