34 research outputs found
Spectrocolorimetric evaluation of repaired articular cartilage after a microfracture
<p>Abstract</p> <p>Background</p> <p>In clinical practice, surgeons differentiate color changes in repaired cartilage compared with surrounding intact cartilage, but cannot quantify these color changes. Objective assessments are required. A spectrocolorimeter was used to evaluate whether intact and repaired cartilage can be quantified.</p> <p>Findings</p> <p>We investigated the use of a spectrocolorimeter and the application of two color models (L* a* b* colorimetric system and spectral reflectance distribution) to describe and quantify articular cartilage. In this study, we measured the colors of intact and repaired cartilage after a microfracture. Histologically, the repaired cartilage was a mixture of fibrocartilage and hyaline cartilage. In the L* a* b* colorimetric system, the L* and a* values recovered to close to the values of intact cartilage, whereas the b* value decreased over time after the operation. Regarding the spectral reflectance distribution at 12 weeks after the operation, the repaired cartilage had a higher spectral reflectance ratio than intact cartilage between wavelengths of 400 to 470 nm.</p> <p>Conclusion</p> <p>This study reports the first results regarding the relationship between spectrocolorimetric evaluation and the histological findings of repair cartilage after a microfracture. Our findings demonstrate the ability of spectrocolorimetric measurement to judge the repair cartilage after treatment on the basis of objective data such as the L*, a* and b* values and the SRP as a coincidence index of the spectral reflectance curve.</p
Antiplatelet Therapy for Prevention of Thromboembolic Complications Associated with Coil Embolization of Unruptured Cerebral Aneurysms
Background: Antiplatelet agents are used during endovascular treatment of cerebral aneurysms to prevent thromboembolic complications. Objective: The aim of this study was to investigate the efficacy of clopidogrel for the prevention of thromboembolic complications during elective coil embolization of unruptured cerebral aneurysms. Methods: Sixty-three patients prospectively received oral clopidogrel 75mg/day from 3 days before and for 1 day after the procedure at our institute (Kohnan Hospital, Sendai, Japan) during 2007. Results: At 24 hours post-coiling, significantly less high-intensity areas, detected by MRI with diffusion-weighted imaging (MRI-DWI), were observed in clopidogrel-treated patients compared with a historical control cohort of aspirin (acetylsalicylic acid)-treated patients (13/63 [20.6%] vs 27/69 [39.1%]; p = 0.02), primarily due to a statistically significantly lower rate during repair of small (<10mm) lesions (p = 0.008).Also, the rate of periprocedural thromboembolic events was lower in the clopidogrel than the aspirin cohort (2/63 [3.2%] vs 5/69 [7.2%]; p = 0.3). Conclusions: Clopidogrel was generally well tolerated with no signs of hemorrhagic complications or liver dysfunction
近赤外線分光法を用いた局所酸素飽和度による熱傷深度測定の検討
The burn severity depends on the wound depth and area affected. Hitherto burn depth has been judged mainly by visual observation, although concerns have been raised about its validity. The regional tissue blood flow (rTBF) measured by laser Doppler imaging (LDI) in damaged tissue correlates with the depth. However, very few reports are available on the significance of the regional tissue oxygen saturation (rSO2) as an indicator of burn depth. We investigated whether rSO2 by Near-infrared spectroscopy (NIRS) in burn injuries correlates with rTBF by LDI, which would facilitate quantification of the severity of the tissue damage. Methods: We measured rTBF and rSO2 in 50 lesions from 14 patients of burn injury within 24 hours after injury. The correlation between rTBF and rSO2 was evaluated by Spearman rank correlation analysis. Results: The rSO2 (%; range, 52-82) by NIRS and the rTBF (perfusion unit; range, 61-704) by LDI in burn lesions were positively correlated (r=0.755, p<0.001). This statistically positive correlation still remained significant (r=0.678, p<0.001) after the rSO2 values were standardized. Conclusion: This study suggests that NIRS determination of rSO2 in burn injuries shows promise as a reliable and quick method to estimate the depth of burn lesion.博士(医学)・乙第1343号・平成26年7月22日© 2014 Seki Tadahiko et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
キカンシ ゼンソク ゾウカ ノ ヨウイン ト サイキン ノ チリョウ ノ トピックス
Increasing asthma prevalence is a major problem in Western countries. Various factors, such as allergic sensitization to indoor allergens, change in incidence in infectious diseases, and increase of air pollutants, are considered to be possible factors for increasing prevalence. Inhaled corticosteroids play an important role in asthma treatment, and its impact on asthma morbidity and mortality has already been established. In addition, recent attention has been focused on molecular targeted therapy in the treatment of bronchial asthma. Promising results of anti-IgE antibody are reported in several clinical trials and anti-CD23 antibody is now introduced in clinical trials
Inhaled steroid therapy and hospitalization for bronchial asthma : trend in Tokushima University Hospital
With the recognition that airway inflammation is present even in patients with mild bronchial asthma, therapy with inhaled corticosteroids is now indicated in various stages of patients. In the present article, we retrospectively examined the prescriptions for inhaled corticosteroids and other drugs for the treatment of outpatients with bronchial asthma at Tokushima University Hospital. We also analyzed asthma control in these patients, in terms of the incidence of emergency consultations and hospitalizations due to asthma exacerbations. To analyze the recent trend, the patients observed from 1998 to 2000 (recent years) were included, and for control purpose, those in 1990 and 1991 (earlier years) were also included.
The percentage of patients treated with inhaled corticosteroids remarkably increased in recent years (mean 81.3%) compared to earlier years (mean 23.5%). In contrast, the usage of oral corticosteroids, oral xanthine derivatives, β2-adrenergic receptor agonists and anti-allergic agents tended to decrease in the 10 years period. After the introduction in 1995, considerable patients up to 25% have been treated with anti-leukotrienes. Emergency consultations decreased in recent years (mean 0.18/patient/year) compared to earlier years (mean 0.79/patient/year). Emergency hospitalizations also decreased in recent years (mean 0.043/patient/year) compared to earlier years (mean 0.23/patient/year).In the present study, spread of inhaled corticosteroid therapy and decline in incidence of emergency consultation and hospitalization were simultaneously observed at Tokushima University Hospital, and the former has, at least in part, a contribution to the latter
Proper magnetic materials selection method for AC filter inductor design used in single phase PWM inverters
The use of wide-bandgap devices such as SiC and GaN has improved the efficiency and power density of power converters compared with conventional Si devices. However, a significant portion of the efficiency loss and volume in power converters is attributed to the magnetic components, particularly the challenges of miniaturization and loss reduction. This is due to the use of nonsinusoidal waveforms, with high-frequency switching of the PWM inverter introducing ripple components that exhibit complex loss characteristics. In this study, we propose a method for selecting magnetic materials for AC filter inductors based on loss and volume considerations. In addition, the effectiveness of the proposed method is validated through experiments
Comparative Study on Hybrid Excitation Flux Switching Motors without and with Variably Magnetizable Permanent Magnets for Electrified Vehicle Propulsion
A demand for high efficiency traction motors has been accelerated by the promotion of electrified vehicles, such as battery and fuel cell electric vehicles. As a part of development of the high efficiency traction motor, this paper reports a comparative study on two kinds of hybrid excitation flux switching motors (HEFSM) as a variable flux machine. One is the conventional HEFSM, which consists of a stator with constantly magnetized-permanent magnets, field excitation coils (FECs) and three-phase armature windings, and a rotor with salient poles like a switched reluctance motor. The other is a HEFSM employing variably magnetizable-permanent magnets (VM-PMs) that replace a part in the FEC slot area in the conventional one. Based on the variable magnetization nature of VM-PMs, the latter HEFSM promises that the replacement of magnetomotive force (mmf) of FECs with that of the VM-PMs makes the motor efficiency better at both low- and high-speed under the low-torque condition, that is, at both urban driving or highway cruising. To verify that, finite element analysis- (FEA)-based design simulations, as well as experimental performance evaluations for the two kinds of HEFSM, were conducted under reasonable dimensional and electrical constraints. As a result, it is shown that the latter HEFSM can achieve higher motor efficiency at the low-torque and high-speed region while keeping the motor efficiency at the low-torque and low-speed region