99 research outputs found

    Prenatal Torsion of Radial Polydactyly: A Gangrenous Mass at the Base of the Thumb

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    A patient was born with a mass at the base of the thumb approximately 1.5 cm in diameter on the radial side of the fingers. The mass had globular swelling filled with hemorrhagic fluid and was dark red. X-rays and histology of the excised specimen suggested the diagnosis of gangrene and torsion of polydactyly. Prenatal torsion of polydactyly is not a common occurrence; moreover, prenatal torsion of polydactyly has only been found in ulnar polydactyly. Our case is a novel case of radial polydactyly that was gangrenous at birth owing to prenatal torsion. Diagnosing such a mass at the base of the thumb is important

    Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam

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    A traffic jam on a highway is a very familiar phenomenon. From the physical viewpoint, the system of vehicular flow is a non-equilibrium system of interacting particles (vehicles). The collective effect of the many-particle system induces the instability of a free flow state caused by the enhancement of fluctuations, and the transition to a jamming state occurs spontaneously if the average vehicle density exceeds a certain critical value. Thus, a bottleneck is only a trigger and not the essential origin of a traffic jam. In this paper, we present the first experimental evidence that the emergence of a traffic jam is a collective phenomenon like 'dynamical' phase transitions and pattern formation in a non-equilibrium system. We have performed an experiment on a circuit to show the emergence of a jam with no bottleneck. In the initial condition, all the vehicles are moving, homogeneously distributed on the circular road, with the same velocity. The average density of the vehicles is prepared for the onset of the instability. Even a tiny fluctuation grows larger and then the homogeneous movement cannot be maintained. Finally, a jam cluster appears and propagates backward like a solitary wave with the same speed as that of a jam cluster on a highway.Sugiyamal Y., Fukui M., Kikuchi M., et al. Traffic jams without bottlenecks-experimental evidence for the physical mechanism of the formation of a jam. New Journal of Physics 10, 033001 (2008); https://doi.org/10.1088/1367-2630/10/3/033001

    Risk factors for excessive postoperative exo-drift after unilateral lateral rectus muscle recession and medial rectus muscle resection for intermittent exotropia

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    Background: To detect significant factors associated with excessive postoperative exo-drift in young patients with intermittent exotropia who had undergone unilateral lateral rectus muscle recession and medial rectus muscle resection. Methods: We retrospectively examined the records of 64 consecutive patients Results: Younger patients (P = 0.007), and those with larger preoperative exo-deviation at distance (P = 0.033), a lower incidence of peripheral fusion at distance (P = 0.021) or a greater postoperative initial eso-deviation (P = 0.001), were significantly more likely to have an excessive postoperative exo-drift (> 20 prism diopters). Univariate analysis revealed significant associations between excessive postoperative exo-drift and age at surgery (P = 0.004), preoperative exo-deviation at distance (P = 0.017) and postoperative initial eso-deviation at distance (P Conclusions: Postoperative exodrift in unilateral RR is predicted by the initial postoperative eso-deviation, which may offset the overcorrection. However, the exo-drift is greater in cases with a large preoperative exo-deviation and/or at a younger age, and should be followed carefully

    Formulas to Estimate Appropriate Surgical Amounts of Unilateral Recession-Resection in Intermittent Exotropia with Distance-Near Disparity

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    The purpose of this study was to derive new formulas to provide an optimal surgical procedure and optimal amount of recession-resection (RR) surgery in intermittent exotropia (IXT) with a disparity in angle of deviation depending on the fixation distance. The records of 117 consecutive patients with IXT who underwent RR surgery between March 2008 and December 2011 at Okayama University Hospital were retrospectively examined. Multivariable linear regression analysis was performed using the observed corrective angle of deviation at distance or near fixation as the dependent variable, and amounts of lateral rectus muscle (LR) recession (mm) and medial rectus muscle (MR) resection, and age at surgery (years) as independent variables. Two simultaneous formulas were derived: corrective angle of deviation at distance fixation (°)=1.8×recession (mm)+1.6× resection (mm)+0.15×age (years)–6.6, and corrective angle at near fixation (°)=1.5×recession (mm)+1.7× resection (mm)+0.18×age (years)–3.8. Comparisons of coefficient values of the formulas between distance and near fixation revealed that LR recession was more affected by the corrective angle in distance than near fixation. MR resection was more affected at near than distance fixation. We found that our new formulas estimated the appropriate amount of unilateral RR surgery

    Differences in the Stability and Amount of Postoperative Exodrift with Age after Unilateral Lateral Rectus Muscle Recession and Medial Rectus Muscle Resection of Intermittent Exotropia

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    We investigated variances in the stability and amount of postoperative exodrift among age groups of intermittent exotropia (XPT) patients who underwent unilateral lateral rectus muscle recession and medial rectus muscle resection. We analyzed the cases of 110 consecutive patients who underwent the surgery in 2004-2011, dividing the patients into groups by their age at surgery: <10, 10-19, and ≥20 years. We performed a regression analysis (dependent variable: postoperative exodrift (°); independent variable: number of days post-surgery) using the formula of curve lines. When the tangent line slope was = 0.01 (°/days) for each group, we defined the numbers of days until alignment became stable as the ‘stable days.’ We evaluated the between-group differences in the amount of exodrift calculated for the stable days. The coefficients and coefficients of determination for the fitting curves were: <10 year group: f(x)=12.2 (1−e−0.0183x) (r2=0.588, p<0.05); 10-19 year group: f(x)=10.0 (1−e−0.0178x) (r2=0.453, p<0.05); ≥20 year group: f(x)=3.40 (1−e−0.0382x) (r2=0.217, p<0.05). There were 389 , 388, and 153 stable days, and the estimated postoperative exodrift with long-term follow-up was 11.5±3.7°, 9.3±4.4°, and 4.1±3.6° for the < 10 year, 10-19 year, and ≥ 20 year groups, respectively (≥20 year vs. other 2 groups, p<0.05). Longer periods and more postoperative exodrift were associated with younger age at surgery. The postoperative evaluation was approx. ≥ 1 year post-surgery in patients aged < 20. These findings may contribute to evaluating XPT’s success rate and prognoses

    Recapitulating the tumor ecosystem along the metastatic cascade using 3D culture models

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    Advances in cancer research have shown that a tumor can be likened to a foreign species that disrupts delicately balanced ecological interactions, compromising the survival of normal tissue ecosystems. In efforts to mitigate tumor expansion and metastasis, experimental approaches from ecology are becoming more frequently and successfully applied by researchers from diverse disciplines to reverse engineer and re-engineer biological systems in order to normalize the tumor ecosystem. We present a review on the use of 3D biomimetic platforms to recapitulate biotic and abiotic components of the tumor ecosystem, in efforts to delineate the underlying mechanisms that drive evolution of tumor heterogeneity, tumor dissemination, and acquisition of drug resistance.ope
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