Refinement of Surgery for Postaxial Polysyndactyly of the Toes: Esthetic Outcome in Japanese Feet.

PURPOSE: Treatment for polysyndactyly of the toes aims at cosmetic improvement but the lateroplantar rotation of the new fifth toe remains challenging. This study evaluated our novel surgical procedure for postaxial polysyndactyly of the toes. MATERIALS AND METHODS: Patients with postaxial polysyndactyly involving the fourth, fifth, and sixth toes treated in 2007 to 2017 with a minimum follow-up duration of 1 year were retrospectively investigated. Our aims of surgery for this condition were to avoid excessive lateroplantar rotation of the new fifth toe by using a proximally elongated plantar "shark-fin flap" and to make the tip of this toe appear to be naturally pointing inward by using the dog-ear component of the flap on the tip of the toe. The excess skin of the shark-fin flap was grafted onto the lateral surface of the fourth toe. Lateroplantar rotation of the fifth toe in these patients was compared with that in photographs of the feet of 96 normal 4-year-old children. RESULTS: A total of 11 feet in 10 patients (6 male, 4 female; mean age 1.3 years) were analyzed. Syndactyly between the fourth and fifth toes was complete in 3 feet, incomplete at the level of the distal interphalangeal joint of the fifth toe in 5, and incomplete at the level of the proximal interphalangeal joint of the fifth toe in 3. Lateroplantar rotation of the fifth toe, evaluated by the mean angle between 2 intersecting lines extending from the proximal nail fold of the third and fifth toes, was 25 ± 10° in normal feet and 0 ± 12° in operated feet with polysyndactyly. The absolute left-right difference in this angle was 7 ± 5° in normal children and 22 ± 12° in patients with polysyndactyly. Valgus deformity of the new fifth toe improved in all patients during a mean postoperative follow-up of 3.8 years. CONCLUSIONS: Using our procedure, no excessive lateroplantar rotation has been observed when the tip of the fifth toe is inclined inward using a dog-ear flap component. This procedure could be useful in patients in whom the cosmetic outcome is a priority.

Restoration of lymph flow by flap transfer can prevent severe lower extremity lymphedema after inguino-pelvic lymphadenectomy.

PURPOSE: Severe lymphedema is difficult to treat because of the associated extensive scar formation. Therefore, preventing scar formation might alleviate the severity of lymphedema following lymphadenectomy. In this study, we evaluated the usefulness of flap transfer, performed immediately after lymphadenectomy, for preventing scar formation. METHODS: Twenty-three patients with subcutaneous malignancy in a lower extremity, who underwent inguino-pelvic lymphadenectomy, were divided into groups based on whether flap transfer was performed. The severity of lymphedema was categorized according to the ratio of the circumference of the affected extremity to that of the unaffected extremity, as mild (< 20% increase in volume), moderate (20-40%), or severe (> 40%). RESULTS: In the 18 patients who underwent lymphadenectomy without flap transfer, lymphedema was classified as mild in 7, moderate in 7, and severe in 4. In the five patients who underwent lymphadenectomy with flap transfer, lymphedema was classified as mild in 4 and moderate in 1. This difference between the groups did not reach significance. CONCLUSIONS: The findings of this study suggest that flap transfer may help prevent scar formation and contribute to the restoration of lymph flow after lymphadenectomy.

Effects of Exercise Training on Mitochondrial Fatty Acid ß-Oxidation in the Kidneys of Dahl Salt-Sensitive Rats.

Exercise training (Ex) has anti-hypertensive and renal protective effects. In this study, we investigate the effects of Ex on mitochondrial fatty acid metabolism in the kidneys of Dahl salt-sensitive (Dahl-S) rats fed a high-salt (HS) diet. Eight-week-old, male Dahl-S rats were divided into three groups: (1) normal-salt diet, sedentary (NS-Sed), (2) HS diet, sedentary (HS-Sed), and (3) HS-Ex. The NS and HS groups were fed a diet containing 0.6% and 8% NaCl, respectively. The HS-Ex group performed treadmill running for 8 weeks (5 days/week; 60 min/day at 16-20 m/min, 0% gradient). Renal function and the expression of enzymes and regulators of ß-oxidation and electron transport chain (ETC) complexes were assessed. HS increased systolic blood pressure and proteinuria, and Ex ameliorated these defects. HS also reduced creatinine clearance, and Ex ameliorated it. HS reduced the renal expression of enzymes of ß-oxidation (carnitine palmitoyltransferase type I (CPTI) and acyl-CoA dehydrogenases (CADs)) and the related transcription factors peroxisome proliferator-activated receptor α (PPARα) and PPARγ-coactivator-1α (PGC-1α), and Ex restored this. HS also reduced the renal expression of enzymes in ETC complexes, and Ex restored this expression. Ex ameliorates HS-induced renal damage by upregulating enzymes involved in fatty acid ß-oxidation and ETC complexes via increases in PPAR-α and PGC-1α expressions in the kidneys of Dahl-S rats. These results suggest that Ex may have beneficial effects on HS-induced mitochondrial dysfunction in the kidney.

Sentinel node restoration by vascularized lymph node transfer in mice.

BACKGROUND: Recent reports have indicated that vascularized lymph node transfer (VLNT) may improve the impaired immunity in lymphedema but there has been no report concerning anti-cancer immunity. In the early tumor immune response, dendritic cells (DCs) participate in tumor recognition and antigen presentation in local lymphatics. Here, we investigated the impact of VLNT on DC dynamics against cancer in mouse models. METHODS: Forty-seven 8-week-old C57BL/6 N male mice were divided into three surgical groups: a VLNT model in which a vascularized inguinal lymph node (LN) flap was transferred into the ipsilateral fossa after a popliteal LN was removed; a LN dissection (LND) model in which the popliteal LN was dissected; and a control model in which a skin incision was made at the popliteal fossa and an ipsilateral inguinal LN was removed. Postoperative lymphatic flows were observed by indocyanine green lymphography and B16-F10-luc2 mouse melanoma were implanted into the ipsilateral footpad. The proportion of DCs in the transplanted nodes was measured by CD11c immunohistochemistry using digital imaging analysis 4 days after cancer implantation. Metastases to the lungs and LNs were quantitatively evaluated by luciferase assay 4 weeks after cancer implantation. RESULTS: After VLNT, lymphatic reconnection was observed in 59.2% of mice. The proportion of DCs was significantly higher in the VLNT group with lymphatic reconnection (8.6% ± 1.0%) than in the naïve LN (4.3% ± 0.4%) (p < .001). The tumor burden of lung metastases was significantly less in the VLNT group with lymphatic reconnection compared with the LND group (p = .049). CONCLUSIONS: Metastasis decreased in mice with reconnected lymphatics after VLNT. A possible explanation was that lymphatic restoration may have contributed to the tumor immune response by allowing DC migration to LNs.

[Treatment of Parastomal Hernia Following Robot-Assisted Radical Cystectomy and Cutaneous Ureterostomy : A Case Report].

The patient was an 82-year-old woman with localized muscle-invasive bladder cancer, who underwent robot-assisted radical cystectomy and cutaneous ureterostomy. On the 3rd day after the operation, she suddenly complained of abdominal pain. Abdominal computed tomographic scans revealed parastomal hernia. The patient underwent manual reduction of hernia, but had repeated recurrences of parastomal hernia within a few days. On the 14th day we performed a laparoscopic hernia repair. Observation of the stoma site revealed a laceration of the peritoneum and fascia, and the small intestine was prolapsed. We pulled the small intestine out and ligated the laceration with Mediflex® Suture Grasper Closure Device. After re-operation, there was no recurrence of bladder cancer and parastomal hernia, and the stoma appliances could be put on without any trouble.

Metformin slows liver cyst formation and fibrosis in experimental model of polycystic liver disease.

Polycystic liver disease (PLD) is a hereditary liver disease in which the number of cysts increases over time, causing various abdominal symptoms and poor quality of life. Although effective treatment for PLD has not been established, we recently reported that long-term exercise ameliorated liver cyst formation and fibrosis with the activation of AMP-activated protein kinase (AMPK) in polycystic kidney (PCK) rats, a PLD model. Therefore, the aim of this study was to investigate whether metformin, an indirect AMPK activator, was effective in PCK rats. PCK rats were randomly divided into a control (Con) group and a metformin-treated (Met) group. The Met group was treated orally with metformin in drinking water. After 12 wk, liver function, histology, and signaling cascades of PLD were examined in the groups. Metformin did not affect the body weight or liver weight, but it reduced liver cyst formation, cholangiocyte proliferation, and fibrosis around the cyst. Metformin increased the phosphorylation of AMPK and tuberous sclerosis complex 2 and decreased the phosphorylation of mammalian target of rapamycin, S6, and extracellular signal-regulated kinase and the expression of cystic fibrosis transmembrane conductance regulator, aquaporin I, transforming growth factor-ß, and type 1 collagen without changes in apoptosis or collagen degradation factors in the liver. Metformin slows the development of cyst formation and fibrosis with the activation of AMPK and inhibition of signaling cascades responsible for cellular proliferation and fibrosis in the liver of PCK rats.NEW & NOTEWORTHY This study indicates that metformin, an indirect AMPK activator slows liver cyst formation and fibrosis in PLD rat model. Metformin attenuates excessive cell proliferation in the liver with the inactivation of mTOR and ERK pathways. Metformin also reduces the expression of proteins responsible for cystic fluid secretion and liver fibrosis. Metformin and AMPK activators may be potent drugs for polycystic liver disease.

Design, synthesis and antitumor activity of phthalazine-1,4-dione-based menaquinone analogs.

New chemotherapeutics are needed to treat hepatocellular carcinoma (HCC), and menaquinones, homologs of vitamin K consisting of a 1,4-naphthoquinone core and a (poly)isoprene chain, are potential candidates. In this study, we designed and synthesized a series of phthalazine-1,4-dione-based menaquinone analogs. Among them, compounds bearing the intact isoprene chain exhibited selective antiproliferative activity towards HCC cell line JHH7, as compared with normal hepatocytes. The geranyl derivative 10 showed submicromolar potency, and might be a promising lead compound for anticancer agents.

Risk Factors for Adverse Events in Patients with Chronic Constipation Following Lubiprostone Administration.

INTRODUCTION: Lubiprostone is an effective treatment of chronic constipation (CC). However, as with other stimulant or osmotic laxatives, adverse events (AEs) can make it difficult to continue treatment. This article investigates AE risk factors associated with lubiprostone. METHODS: We retrospectively analyzed all 1,338 Japanese patients with CC treated at our hospital from October 2013 to July 2017. All patients were diagnosed with constipation as defined by the Roma III criteria. Enrolled patients received lubiprostone orally (24 or 48 µg daily), after which we investigated the incidence of AEs. The causative factors for diarrhea and nausea, the most common AEs, were examined by the backward logistic regression model. RESULTS: Two hundred eight (15.5%) experienced at least 1 AE. No serious AEs were associated with the study drug. The AEs reported by >1% of patients overall were diarrhea (6.1%) and nausea (4.2%). We performed a multivariate logistic regression using a backward variable selection method to investigate AE risk factors. Factors associated with higher incidence of diarrhea were patient age of 65 years or more (odds ratio: [95% confidence interval]; p value) (2.09: [1.05-4.16]; 0.035). Factors associated with greater likelihood of nausea included female gender (1.99: [1.10-3.61]; 0.023), and the chief complaint was a patient complaining of abdominal pain and fullness (2.07: [1.01-4.22]; 0.046). CONCLUSIONS: Understanding AE risk factors can help avoid unnecessary AEs and promote more effective treatment.

Combined internal and external negative pressure wound therapy: breakthrough treatment for lymphocutaneous intractable fistula.

PURPOSE: Lymphocutaneous fistula after lymph node dissection is intractable, yet there is no established treatment strategy. This study demonstrates the wound closure time achieved by a new method of combined internal and external negative pressure wound therapy (CIEN) in patients with lymphocutaneous fistula. METHODS: The subjects of this study were six consecutive patients with lymphocutaneous fistula after lymphatic surgery, who were treated with CIEN between 2018 and 2020. The CIEN technique can be summarized as follows: first, internal foam is inserted into the fistula from the opening of the fenestration. Next, a slightly larger area of external foam is applied above the fistula flap outside the external margin of the foam-filled fistula. After bridging the internal foam and external foam, negative-pressure wound therapy is carried out on this bridging foam block. RESULTS: CIEN led to rapid and complete wound healing in all six patients. Fistula flap margin ischemia developed in one patient, but adjusting the mode and pressure settings resulted in improvement. Three patients suffered contact dermatitis. There were no signs of tumor or fistula recurrence in any patients after at least 3 months of follow-up. CONCLUSION: CIEN is an effective and less invasive treatment modality than the conventional method of managing lymphocutaneous fistula.

Angiotensin II upregulates CYP4A isoform expression in the rat kidney through angiotensin II type 1 receptor.

Angiotensin II (AngII) stimulates the renal production and release of 20-hydroxyeicosatetraenoic acids (20-HETE), which is a major metabolite of arachidonic acid catalyzed by CYP4A isoforms. However, the effects of AngII on CYP4A isoform expression in the kidney and its mechanism remains unclear. To clarify the regulation of CYP4A isoform expression by AngII, we examined the chronic effects of AngII and AngII type 1 receptor (AT1-R) blockade on CYP4A isoform expression. Sprague-Dawley rats were infused with vehicle or AngII for 1 week, and the AngII-infused rats were also treated with or without the AT1-R blocker, candesartan. AngII increased CYP4A isoform protein expression in the renal cortex (CO) and outer medulla (OM) in a dose-dependent manner, and candesartan inhibited the AngII-increased CYP4A expression in a dose-dependent manner. AngII increased the CYP4A isoform mRNA expression in the CO and OM, and candesartan inhibited AngII-increased CYP4A isoform mRNA expression. These results indicated that AngII chronically increased the CYP4A isoform expression in the rat kidney. The AngII-induced CYP4A isoform expression was mediated by AT1-R.

Determining the Influence of Granule Size on Simulation Parameters and Residual Shear Stress Distribution in Tablets by Combining the Finite Element Method into the Design of Experiments.

The influence of granule size on simulation parameters and residual shear stress in tablets was determined by combining the finite element method (FEM) into the design of experiments (DoE). Lactose granules were prepared using a wet granulation method with a high-shear mixer and sorted into small and large granules using sieves. To simulate the tableting process using the FEM, parameters simulating each granule were optimized using a DoE and a response surface method (RSM). The compaction behavior of each granule simulated by FEM was in reasonable agreement with the experimental findings. Higher coefficients of friction between powder and die/punch (µ) and lower by internal friction angle (αy) were generated in the case of small granules, respectively. RSM revealed that die wall force was affected by αy. On the other hand, the pressure transmissibility rate of punches value was affected not only by the αy value, but also by µ. The FEM revealed that the residual shear stress was greater for small granules than for large granules. These results suggest that the inner structure of a tablet comprising small granules was less homogeneous than that comprising large granules. To evaluate the contribution of the simulation parameters to residual stress, these parameters were assigned to the fractional factorial design and an ANOVA was applied. The result indicated that µ was the critical factor influencing residual shear stress. This study demonstrates the importance of combining simulation and statistical analysis to gain a deeper understanding of the tableting process.

Mechanical Stress Simulation of Scored Tablets Based on the Finite Element Method and Experimental Verification.

Scored tablets can be divided into equal halves for individual treatment of patients. However, the relationships between scored shapes and tablet characteristics such as the dividing strength, halving equality, and breaking strength are poorly understood. The purpose of this study was to simulate the mechanical stress distribution of scored tablets by using the finite element method (FEM). A runnel of triangle pole on the top surface of flat tablets was fabricated as the score shape. The depth and angle of the scores were selected as design variables. Elastic parameters such as a Young's modulus and a Poisson ratio for the model powder bed were measured. FEM simulation was then applied to the scored tablets, represented as a continuum elastic model. Stress distributions in the inner structure of the tablets were simulated after applying external force. The adequacy of the simulation was evaluated in experiments using scored tablets. As a result, we observed a relatively good agreement between the FEM simulation and the experiments, suggesting that FEM simulation is advantageous for designing scored tablets.

Numerical Investigation of the Residual Stress Distribution of Flat-Faced and Convexly Curved Tablets Using the Finite Element Method.

The stress distribution of tablets after compression was simulated using a finite element method, where the powder was defined by the Drucker-Prager cap model. The effect of tablet shape, identified by the surface curvature, on the residual stress distribution was investigated. In flat-faced tablets, weak positive shear stress remained from the top and bottom die walls toward the center of the tablet. In the case of the convexly curved tablet, strong positive shear stress remained on the upper side and in the intermediate part between the die wall and the center of the tablet. In the case of x-axial stress, negative values were observed for all tablets, suggesting that the x-axial force always acts from the die wall toward the center of the tablet. In the flat tablet, negative x-axial stress remained from the upper edge to the center bottom. The x-axial stress distribution differed between the flat and convexly curved tablets. Weak stress remained in the y-axial direction of the flat tablet, whereas an upward force remained at the center of the convexly curved tablet. By employing multiple linear regression analysis, the mechanical properties of the tablets were predicted accurately as functions of their residual stress distribution. However, the multiple linear regression prediction of the dissolution parameters of acetaminophen, used here as a model drug, was limited, suggesting that the dissolution of active ingredients is not a simple process; further investigation is needed to enable accurate predictions of dissolution parameters.

Effect of process variables on the Drucker-Prager cap model and residual stress distribution of tablets estimated by the finite element method.

A multivariate statistical technique was applied to clarify the causal correlation between variables in the manufacturing process and the residual stress distribution of tablets. Theophylline tablets were prepared according to a Box-Behnken design using the wet granulation method. Water amounts (X1), kneading time (X2), lubricant-mixing time (X3), and compression force (X4) were selected as design variables. The Drucker-Prager cap (DPC) model was selected as the method for modeling the mechanical behavior of pharmaceutical powders. Simulation parameters, such as Young's modulus, Poisson rate, internal friction angle, plastic deformation parameters, and initial density of the powder, were measured. Multiple regression analysis demonstrated that the simulation parameters were significantly affected by process variables. The constructed DPC models were fed into the analysis using the finite element method (FEM), and the mechanical behavior of pharmaceutical powders during the tableting process was analyzed using the FEM. The results of this analysis revealed that the residual stress distribution of tablets increased with increasing X4. Moreover, an interaction between X2 and X3 also had an effect on shear and the x-axial residual stress of tablets. Bayesian network analysis revealed causal relationships between the process variables, simulation parameters, residual stress distribution, and pharmaceutical responses of tablets. These results demonstrated the potential of the FEM as a tool to help improve our understanding of the residual stress of tablets and to optimize process variables, which not only affect tablet characteristics, but also are risks of causing tableting problems.

Examining How Interaural Differences Owing to Head Rotation during Walking Improve the Distance of Auditory Obstacle Perceptions among Individuals with Visual Impairment: A Case Study in Small-Scale Blind Group.

The ability of individuals with visual impairment to recognize an obstacle by hearing is called "obstacle sense". This ability is facilitated while they are moving, though the exact reason remains unknown. This study aims to clarify which acoustical factors may contribute to obstacle sense, especially obstacle distance perception. First, we conducted a comparative experiment regarding obstacle distance localization by individuals who are blind (N = 5, five men with blindness aged 22-42 (average: 29.8)) while they were standing and walking. The results indicate that the localized distance was more accurate while walking than while standing. Subsequently, the head rotation angle while walking and acoustic characteristics with respect to obstacle distance and head rotation angle were investigated. The peaks of the absolute head rotation angle during walking ranged from 2.78° to 11.11° (average: 6.55°, S.D.: 2.05°). Regarding acoustic characteristics, acoustic coloration occurred, and spectral interaural differences and interaural intensity differences were observed in the blind participants (N = 4, four men including two blind and two control sighted persons aged 25-38 (average: 30.8)). To determine which acoustic factors contribute, we examined the threshold of changes for interaural differences in time (ITD) and intensity (IID) (N = 11, seven men and four women with blindness aged 21-35 (average: 27.4)), as well as coloration (ICD) (N = 6, seven men and a woman with blindness aged 21-38 (average: 29.9))-depending on the head rotation. Notably, ITD and IID thresholds were 86.2 µs and 1.28 dB; the corresponding head rotation angles were 23.5° and 9.17°, respectively. The angle of the ICD threshold was 6.30° on average. Consequently, IID might be a contributing factor and ICD can be utilized as the cue facilitating the obstacle distance perception while walking.

Fluoroscopy- and Endoscopy-Guided Transoral Sclerotherapy Using Foamed Polidocanol for Oropharyngolaryngeal Venous Malformations in a Hybrid Operation Room: A Case Series.

Background: Treatment of oropharyngolaryngeal venous malformations (VMs) remains challenging. This study evaluated the effectiveness and safety of fluoroscopy- and endoscopy-guided transoral sclerotherapy for oropharyngolaryngeal VMs in a hybrid operation room (OR). Methods: Patients with oropharyngolaryngeal VMs who underwent transoral sclerotherapy in a hybrid OR were enrolled. Results: Fourteen patients (six females, eight males; median age of 26 years; range, 4-71 years) were analyzed. The symptoms observed were breathing difficulties (n = 3), snoring (n = 2), sleep apnea (n = 1), and swallowing difficulties (n = 1). Lesions were extensive in the face and neck (n = 9) and limited in the oropharyngolarynx (n = 5). A permanent tracheostomy was performed on two patients, while a temporary tracheostomy was performed on five patients. The treated regions were the soft palate (n = 8), pharynx (n = 7), base of the tongue (n = 4), and epiglottis (n = 1). The median number of sclerotherapy sessions was 2.5 (range, 1-9). The median follow-up duration was 81 months (range, 6-141). Treatment outcomes were graded as excellent (n = 2), good (n = 7), or fair (n = 5). The post-treatment complication was bleeding (n = 1), resulting in an urgent tracheostomy. Conclusions: Fluoroscopy- and endoscopy-guided transoral sclerotherapy in a hybrid OR can be effective and safe for oropharyngolaryngeal VMs.

Long-term course of untreated asymptomatic esophageal eosinophilia and minimally symptomatic eosinophilic esophagitis.

Background and study aims The long-term course of untreated asymptomatic esophageal eosinophilia (aEE) and minimally symptomatic eosinophilic esophagitis (mEoE) are not well understood. This study aimed to clarify this course. Patients and methods A total of 36 patients with EE who were endoscopically followed up for more than 5 years, and who underwent more than one endoscopy evaluation after the first diagnosis, were investigated. These patients were divided into two groups according to the presence or absence of the continuous treatment: no treatment group (NT group, n=22) and proton pump inhibitor/potassium competitive acid blocker group (Tx group, n=14). Symptoms and endoscopic and histological findings were retrospectively reviewed according to endoscopic phenotypes. Endoscopic assessment was performed using the EoE endoscopic reference score (EREFS). Results The median follow-up period was 84.5 months in the Tx group and 92 months in the NT group. During the follow-up period, about half of the patients in the Tx-diffuse group persisted EREFS >3, while the remaining half had EREFS ≤2. The total EREFS in the NT-diffuse group remained almost unchanged (median: 2-4) without apparent exacerbation. In contrast, EREFS in the NT-localized group exhibited an unchanged or gradually decreasing trend, with statistical significance from the first diagnosis to 72 to 83 months after. Conclusions Untreated aEE and mEoE are not likely to worsen even without treatment at least for a median follow-up of 7 years. Instead, the localized type may spontaneously improve, implying a different pathogenesis in the presence of the diffuse type. Further studies should clarify the long-term prognosis.

Young Patient with X-linked Agammaglobulinemia Presents with Advanced Gastric Cancer and Extensive Atrophic Gastritis.

X-linked agammaglobulinemia (XLA) is associated with an increased risk of gastrointestinal cancers including gastric cancer (GC). We herein report the case of a 30-year-old male patient with XLA who developed GC and extensive atrophic gastritis. He tested positive in the urea breath test, thus indicating the presence of Helicobacter pylori. Distal gastrectomy and chemotherapy were performed without any complications; however, the died two years after this diagnosis. Immunoglobulin deficiency makes these patients susceptible to progressive atrophic gastritis and the associated risk of GC. Therefore, patients with XLA are advised to undergo an evaluation for Helicobacter pylori infection as well as monitoring for GC.

[Optimal scan parameters for a method of k-space trajectory (radial scan method) in evaluation of carotid plaque characteristics].

The purpose of this study was to optimize scan parameters for evaluation of carotid plaque characteristics by k-space trajectory (radial scan method), using a custom-made carotid plaque phantom. The phantom was composed of simulated sternocleidomastoid muscle and four types of carotid plaque. The effect of chemical shift artifact was compared using T1 weighted images (T1WI) of the phantom obtained with and without fat suppression, and using two types of k-space trajectory (the radial scan method and the Cartesian method). The ratio of signal intensity of simulated sternocleidomastoid muscle to the signal intensity of hematoma, blood (including heparin), lard, and mayonnaise was compared among various repetition times (TR) using T1WI and T2 weighted imaging (T2WI). In terms of chemical shift artifacts, image quality was improved using fat suppression for both the radial scan and Cartesian methods. In terms of signal ratio, the highest values were obtained for the radial scan method with TR of 500 ms for T1WI, and TR of 3000 ms for T2WI. For evaluation of carotid plaque characteristics using the radial scan method, chemical shift artifacts were reduced with fat suppression. Signal ratio was improved by optimizing the TR settings for T1WI and T2WI. These results suggest the potential for using magnetic resonance imaging for detailed evaluation of carotid plaque.

Binaural Listening with Head Rotation Helps Persons with Blindness Perceive Narrow Obstacles.

Orientation and mobility (O&M) are important abilities that people with visual impairments use in their independent performance of daily activities. In orientation, people with total blindness pinpoint nonsounding objects and sounding objects. The ability to perceive nonsounding objects is called obstacle sense, wherein people with blindness recognize the various characteristics of an obstacle using acoustic cues. Although body movement and listening style may enhance the sensing of obstacles, experimental studies on this topic are lacking. Elucidating their contributions to obstacle sense may lead to the further systematization of techniques of O&M training. This study sheds light on the contribution of head rotation and binaural hearing to obstacle sense among people with blindness. We conducted an experiment on the perceived presence and distance of nonsounding obstacles, which varied width and distance, for participants with blindness under the conditions of binaural or monaural hearing, with or without head rotation. The results indicated that head rotation and binaural listening can enhance the localization of nonsounding obstacles. Further, when people with blindness are unable to perform head rotation or use binaural hearing, their judgment can become biased in favor of the presence of an obstacle due to risk avoidance.