92 research outputs found

    Recovery of Small-Sized Blood Vessels in Ischemic Bone Under Static Magnetic Field

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    Effects of static magnetic field (SMF) on the vascularization in bone were evaluated using an ischemic bone model, where rat femoral artery was ligated. Magnetized and unmagnetized samarium–cobalt rods were implanted transcortically into the middle diaphysis of the ischemic femurs. Collateral circulation was evaluated by injection of microspheres into the abdominal aorta at the third week after ligation. It was found that the bone implanted with a magnetized rod showed a larger amount of trapped microspheres than that with an unmagnetized rod at the proximal and the distal region (P < 0.05 proximal region). There were no significant differences at the middle and the distal region. This tendency was similar to that of the bone mineral density in the SMF-exposed ischemic bone

    Recovery Effects of a 180 mT Static Magnetic Field on Bone Mineral Density of Osteoporotic Lumbar Vertebrae in Ovariectomized Rats

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    The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT) was implanted to the right side of spinous process of the third lumbar vertebra. Female rats in the growth stage (10 weeks old) were randomly divided into 4 groups: (i) ovariectomized and implanted with a disc magnet (SMF); (ii) ovariectomized and implanted with a nonmagnetized disc (sham); (iii) ovariectomized alone (OVX) and (vi) intact, nonoperated cage control (CTL). The blood serum 17-β-estradiol (E2) concentrations were measured by radioimmunoassay, and the bone mineral density (BMD) values of the femurs and the lumbar vertebrae were assessed by dual energy X-ray absorptiometry. The E2 concentrations were statistically significantly lower for all three operated groups than those of the CTL group at the 6th week. Although there was no statistical significant difference in the E2 concentrations between the SMF-exposed and sham-exposed groups, the BMD values of the lumbar vertebrae proximal to the SMF-exposed area statistically significantly increased in the SMF-exposed group than in the sham-exposed group. These results suggest that the SMF increased the BMD values of osteoporotic lumbar vertebrae in the ovariectomized rats

    ブドウ球菌の表皮ケラチノサイトからの選択的抗菌ペプチドの誘導

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    Staphylococcus aureus (S. aureus) is one of the most clinically important inflammation-inducing pathogens, while Staphylococcus epidermidis (S. epidermidis) is nonpathogenic and hardly causes inflammation on skin. β-defensins, antimicrobial peptides, are secreted from keratinocytes constitutively or upon induction by various microorganisms. However, the difference between S. aureus and S. epidermidis is still unclear in terms of their influences on the production of β-defensins. In this study, we focused on the influences of S. aureus and S. epidermidis on the keratinocyte innate immune response. Pathogenic S. aureus mainly induced human β-defensin (hBD) 1 and hBD3, but not hBD2, and nonpathogenic S. epidermidis mainly induced hBD2 from human keratinocytes. Molecular weight fractions of >10 kDa prepared from S. aureus supernatants induced the production of hBD1 and hBD3. On the other hand, molecular weight fraction of >100 kDa prepared from S. epidermidis supernatants induced the production of hBD2.Furthermore, the secreted products of S. epidermidis used the toll-like receptor (TLR) 2 pathway in the induction of hBD2 production. The secreted products of S. aureus and S. epidermidis differentially induced subtypes of hBD through different receptors, which may be associated with the difference in virulence between these two bacteria.博士(医学)・甲第643号・平成28年3月15日Copyright © 2012 Elsevier Ltd. All rights reserved

    高齢者における日中光曝露が夜間尿中メラトニン分泌への与える影響 : 平城京スタディ横断解析

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    CONTEXT:Melatonin is involved in a variety of diseases, including cancer, insomnia, depression, dementia, hypertension, and diabetes; its secretion is influenced by environmental light. Although daylight exposure increases nocturnal melatonin secretion in a controlled laboratory setting, whether it increases nocturnal melatonin secretion in an uncontrolled daily life setting remains unclear.OBJECTIVE:We aimed to determine the association between daylight exposure in an uncontrolled daily life setting and urinary 6-sulfatoxymelatonin excretion.DESIGN AND PARTICIPANTS:A cross-sectional study was conducted in 192 elderly individuals (mean age, 69.9 yr).MEASURES:We measured ambulatory daylight exposure using a wrist light meter in two 48-h sessions; furthermore, we measured overnight urinary 6-sulfatoxymelatonin excretion, an index of melatonin secretion, on the second night of each session.RESULTS:The median duration of daylight exposure of at least 1000 lux was 72 min (interquartile range, 37-124). Univariate linear regression analysis showed marginal to significant associations between log-transformed urinary 6-sulfatoxymelatonin excretion and age, current smoking status, benzodiazepine use, day length, log-transformed duration of daylight exposure of at least 1000 lux, and daytime physical activity. In a multivariate model, log-transformed duration of daylight exposure of at least 1000 lux was significantly associated with log-transformed urinary 6-sulfatoxymelatonin excretion (regression coefficient, 0.101; 95% confidence interval, 0.003-0.199; P = 0.043). Furthermore, an increase in the duration of daylight exposure of at least 1000 lux from 37 to 124 min (25th to 75th percentiles) was associated with a 13.0% increase in urinary 6-sulfatoxymelatonin excretion (6.8 to 7.7 μg).CONCLUSIONS:Daylight exposure in an uncontrolled daily life setting is positively associated with urinary 6-sulfatoxymelatonin excretion in the elderly.博士(医学)・乙第1308号・平成25年3月15日Copyright © 2012 by The Endocrine Societ

    Static Magnetic Field Effects on Impaired Peripheral Vasomotion in Conscious Rats

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    We investigated the SMF effects on hemodynamics in the caudal artery-ligated rat as an in vivo ischemia model using noninvasive near-infrared spectroscopy (NIRS) combined with power spectral analysis by fast Fourier transform. Male Wistar rats in the growth stage (10 weeks old) were randomly assigned into four groups: (i) intact and nonoperated cage control (n=20); (ii) ligated alone (n=20); (iii) ligated and implanted with a nonmagnetized rod (sham magnet; n=22); and (vi) ligated and implanted with a magnetized rod (n=22). After caudal artery ligation, a magnetized or unmagnetized rod (maximum magnetic flux density of 160 mT) was implanted transcortically into the middle diaphysis of the fifth caudal vertebra. During the experimental period of 7 weeks, NIRS measurements were performed in 3- , 5- , and 7-week sessions and the vasomotion amplitude and frequency were analyzed by fast Fourier transform. Exposure for 3–7 weeks to the SMF significantly contracted the increased vasomotion amplitude in the ischemic area. These results suggest that SMF may have a regulatory effect on rhythmic vasomotion in the ischemic area by smoothing the vasomotion amplitude in the early stage of the wound healing process

    Effectiveness of a new gelatin sealant system for dural closure.

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    Objectives:Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage.Methods:The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated.Results:The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P < 0·001) or the PEG-based hydrogel sealant (46·3 ± 20·9 mmHg, P  =  0·007). Bonding strength was higher for the gelatin glue than fibrin glue (P < 0·001) or PEG-based hydrogel sealant (P  =  0·001). The maximum intracranial pressure in the in vivo model was higher for the gelatin glue group (59·0 ± 2·2 mmHg) than the control group (13·8 ± 4·0 mmHg, P < 0·001). Tissue adhesion was lower for the gelatin glue group than the control group (P  =  0·005).Discussion:The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.博士(医学)・甲第634号・平成27年5月28日© 2015 W. S. Maney & Son LtdThe definitive version is available at " http://dx.doi.org/10.1179/1743132814Y.0000000342

    新生児の睡眠中の心拍変動周波数スペクトルと自律神経活動の関係

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    INTRODUCTION: We analyzed the frequency spectrum of two neonatal sleep stages, namely active sleep and quiet sleep, and the relationship between these sleep stages and autonomic nervous activity in 74 newborns and 16 adults as a comparison. METHOD: Active and quiet sleep were differentiated by electroencephalogram (EEG) patterns, eye movements, and respiratory wave patterns; autonomic activity was analyzed using the RR interval of simultaneously recorded electrocardiogram (ECG) signals. Power values (LFa, absolute low frequency; HFa, absolute high frequency), LFa/HFa ratio, and the values of LFn (normalized low frequency) and HFn (normalized high frequency) were obtained. Synchronicity between the power value of HFa and the LFa/HFa ratio during active and quiet sleep was also examined by a new method of chronological demonstration of the power values of HFa and LFa/HFa. RESULTS: We found that LFa, HFa and the LFa/HFa ratio during active sleep were significantly higher than those during quiet sleep in newborns; in adults, on the other hand, the LFa/HFa ratio during rapid eye movement (REM) sleep, considered as active sleep, was significantly higher than that during non-REM sleep, considered as quiet sleep, and HFa values during REM sleep were significantly lower than those during non-REM sleep. LFn during quiet sleep in newborns was significantly lower than that during active sleep. Conversely, HFn during quiet sleep was significantly higher than that during active sleep. Analysis of the four classes of gestational age groups at birth indicated that autonomic nervous activity in a few preterm newborns did not reach the level seen in full-term newborns. Furthermore, the power value of HFa and the LFa/HFa ratio exhibited reverse synchronicity. CONCLUSION: These results indicate that the autonomic patterns in active and quiet sleep of newborns are different from those in REM and non-REM sleep of adults and may be develop to the autonomic patterns in adults, and that parasympathetic activity is dominant during quiet sleep as compared to active sleep from the results of LFn and HFn in newborns. In addition, in some preterm infants, delayed development of the autonomic nervous system can be determined by classifying the autonomic nervous activity pattern of sleep stages.博士(医学)・乙第1418号・平成30年3月15日© 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved

    心臓血管外科領域におけるゼラチンシートの止血効果、癒着防止効果の検討

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    BACKGROUND:The bi1ayer gelatin sealing sheet was developed as a safe, effective, easy-to-handle and low-cost hemostatic agent. OBJECTIVE:To examine the feasibility of gelatin sealing sheets using a canine aterial hemorrhage mode1. METHODS:In vivo degradation of gelatin sealing sheets was examined by implanting subcutaneously in rats. For the hemostatic and anti-adhesion efficacy investigations, femoral arteries of dogs were pricked with syringe needle to make as mall hole, and a gelatin(i.e. experimental group) or fibrin glue sealing sheet (i.e. control group) was applied on the hole to stop bleeding (n=8). After discontinuation of the bleeding, the skin incisions were closed and re-examined 4 weeks postoperatively. RESULTS:From the degradation study, 4h thermally treated gelatin sheet which degraded within 3 weeks in vivo was chosen for the further hemostatic study. In all cases of gelatin and fibrin glue sealing sheets, bleeding from the needle hole on canine femoral arteries was effectively stopped. Postoperative adhesions and inflammation at the site in the experimental group were significantly less than those in the control group (P<0.01 for adhesion scores). CONCLUSIONS:The gelatin sealing sheet was found to be as effective as the fibrin glue sealing sheet as a surgical hemostatic agent, and more effective in preventing postoperative adhesions.博士(医学)・甲第632号・平成27年3月16日Copyright ©2015 IOS Pres
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