609 research outputs found

    Elevation by Oxidative Stress and Aging of Hypothalamic-Pituitary-Adrenal Activity in Rats and Its Prevention by Vitamin E

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    The present study was conducted in order to determine whether oxidative stress during aging involves dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis in association with the emergence of cognitive deficits. When young rats were subjected to oxidative stress in the form of hyperoxia, thiobarbituric acid reactive substances, conjugated diene and lipid hydroperoxides increased markedly in the HPA axis. Vitamin E inhibited such increases in lipid peroxides in each organ. Levels of corticotrophin-releasing hormone in the hypothalamus and plasma levels of adrenocorticotrophic hormone and corticosterone were markedly elevated in young rats exposed to hyperoxia. However, young rats fed vitamin E-supplemented diets showed no abnormal hormone secretion, even after being subjected to hyperoxia. Furthermore, glucocorticosteroid receptors (GR) in pyramidal cells in the Cornus ammonis 1 region of the hippocampus in young rats were markedly decreased by oxidative stress. Similar phenomena were also observed in normal aged rats and young rats fed vitamin E-deficient diet kept in a normal atmosphere. Vitamin E supplementation prevented the decrease in GR in the hippocampus and the increase in corticosterone secretion caused by hyperoxia. These results suggest that oxidative stress induces oxidative damage in the hippocampus and the HPA axis during aging, resulting in a cognitive deficit in rats, and that negative-feedback inhibition on HPA activity was markedly dampened due to an increase in corticosterone levels caused by loss of GR

    Atomic-scale processes at the fluorite-water interface visualized by frequency modulation atomic force microscopy

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    The crystal growth and dissolution processes of a fluorite (CaF 2) crystal have attracted much attention due to the importance in the industrial, environmental, and medical applications. While previous studies clarified nanoscale processes at the fluorite-water interface, atomic-scale origins of the processes have yet to be understood. In this study, we have investigated atomic-scale processes at the fluorite-water interface by frequency modulation atomic force microscopy (FM-AFM). We performed atomic-resolution imaging of a fluorite(111) surface in water (pH = 2 and 6.5), saturated solution (pH = 2 and 6), and supersaturated solution (pH = 6, σ = 10 and 100). Based on the results, we present three major findings. First, atomic-scale roughening of the crystal surface takes place at low pH due to the proton adsorption. Second, surface adsorbates with a subnanometer-scale height are formed on the crystal surface at high pH. They are most likely to be calcium hydroxo complexes physisorbed on the crystal surface. Finally, the formation of these complexes can be suppressed by increasing fluorite concentration owing to the increased proportion of Ca2+ and F- in the electric double layer. These findings mark an important step toward the full understanding of the physicochemical processes at the fluorite-water interface. © 2013 American Chemical Society

    Utility of a Computed Tomography-Based Navigation System (O-Arm) for Partial Vertebrectomy for Lung Cancer Adjacent to the Thoracic Spine: Technical Case Report

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    We describe successful vertebrectomy from a posterior approach using a computed tomography (CT)-based navigation system (O-arm) in a 53-year-old man with adenocarcinoma of the posterior apex of the right lung with invasion of the adjacent rib, thoracic wall, and T2 and T3 vertebral bodies. En bloc partial vertebrectomy for lung cancer adjacent to the thoracic spine was planned using O-arm. First, laminectomy was performed from right T2 to T3, and pedicles and transverse processes of T2 to T3 were resected. O-arm was used to confirm the location of the cutting edge in the T2 to 3 right vertebral internal body, and osteotomy to the anterior cortex was performed with a chisel. Next, the patient was placed in a left decubitus position. The surgical specimen was extracted en bloc. This case shows that O-arm can be used reliably and easily in vertebrectomy from a posterior approach and can facilitate en bloc resection

    Outcomes of Charnley total hip arthroplasty using improved cementing with so-called second- and third-generation techniques

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    AbstractBackgroundTechniques of cemented total hip arthroplasty have developed over time. We present the outcomes of Charnley total hip arthroplasty performed using improved second- and third-generation cementing techniques.MethodsWe reviewed the radiologic results of 91 Charnley total hip arthroplasties performed using second- and third-generation cementing techniques. Second-generation techniques involved making multiple anchor holes, a double-cementing method on the acetabular side and an intramedullary plug, and retrograde filling with a cement gun on the femoral side in 57 hips. Third-generation techniques involved additional vacuum mixing and cement pressurization in 34 hips.ResultsJoint survival rates at 20years when using second-generation techniques were 89% for the socket and 94% for the stem with aseptic loosening as the end point; the survival rates at 10years when using third-generation techniques were 97 and 100%, respectively. According to our radiographic evaluation system for the clear zone at 5years, there was less clear zone in the acetabular side with the third-generation techniques than with second-generation techniques. In the femoral side, there was very little development of the clear zone, but the difference between generations was not significant.ConclusionsSecond- and third-generation cementing techniques showed excellent survivorship. The clear zone scores at 5years indicated that third-generation techniques were effective, especially in the acetabular side, and may produce better long-term results than second-generation techniques

    <症例>胃癌手術 (脾摘術合併胃全摘術) 後の門脈血栓症の1例

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    A 48-year-old woman underwent total gastrectomy, splenectomy, and distal pancreatectomy with en bloc regional lymph node dissection for gastric carcinoma. Dull pain in the right upper quadrant and the back developed postoperatively. Contrast-enhanced computed tomography and ultrasonography disclosed portal vein thrombosis (PVT). Heparin and urokinase were given in conjunction with antbiotics. This treatment resulted in clinical improvement, but failed to achieve complete thrombolysis. Cavernous transformation of the portal system was confirmed. Although PVT after splenectomy has been reported mainly in patients with hematological disorders, our case suggests that splenectomy for en bloc node dissection in gastric carcinoma is a possible cause of PVT.門脈血栓症は肝硬変や肝癌の患者で時に認められる病態であるが, 術後の門脈血栓症は稀であり, そのほとんどが脾腫に対する脾摘術後に発生している. 我々は胃癌根治術に伴う脾摘術後に門脈血栓をきたした症例を経験したので報告する. 症例は48才の女性で, 胃体上部後壁を中心とする5型胃癌に対し, 胃全摘術, 脾摘術, 膵尾側切除術を行なった. 病変は組織学的には低分化腺癌, 深達度ss, No, Po, Ho の stage I b で, 摘出した脾重量は 150g であった. なお, 術前の出血凝固系検査には異常を認めなかった. 術後18日目より右上腹部から背部の鈍痛が出現し, 白血球数, CRP, 血清アルカリフォスファターゼ値も上昇してきた. 術後19日目の造影CTで, 門脈, 上腸間膜静脈がほとんど造影されず, 門脈から上腸間膜静脈におよぶ血栓形成が考えられた. 抗生剤の投与とともにただちにへパリンの持続静注とウロキナーゼ投与を併用したところ, 臨床症状や検査所見は軽快した. ただし, 血栓は完全に消失せず, その後の腹部血管造影では側副血行路としての肝十二指腸間膜内の静脈拡張, いわゆるcavernous transformation が認められた. へパリン, ウロキナーゼの投与からワーファリン内服に切り替え, 患者は術後66日目に退院した. 現在, 術後2年経過したが, 食道静脈瘤の出現や消化管出血などの門脈血栓, 門脈圧充亢進に起因すると思われる症状は認めていない. 我々の症例は, 進行胃癌根治術の際にしばしは合わせ行われる脾摘術後にも門脈血栓症の出現する可能性があることを示唆しており, そのような手術を受けた患者が術後原因不明の腹部症状や白血球増加を来たした時には門脈血栓症も疑い精査を進める必要があると考えられる

    Local Control of Squamous Cell Carcinoma of the Cervix Treated with CT-based Three-dimensional Image-Guided Brachytherapy with or without Central Shielding

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    The purposes of this retrospective study were to analyze local control of squamous cell carcinoma of the cervix treated with computed tomography (CT)-based image-guided brachytherapy (IGBT), as well as the factors affecting local control. A total of 39 patients were analyzed. The prescribed dose to the pelvis was 45-50 Gy with or without central shielding (CS). IGBT was delivered in 1-5 fractions. The total dose for high-risk clinical target volume (HR-CTV) was calculated as the biologically equivalent dose in 2-Gy fractions. The median follow-up period was 29.3 months. The 2-year overall survival and local control rates were 97% and 91%, respectively. In univariate analysis, the dose covering 90% of the HR-CTV (D90) and tumor size were found to be significant factors for local control. The cutoff values of tumor size and D90 for local control were 4.3 cm (area under the curve [AUC] 0.75) and 67.7 Gy (AUC 0.84) in the CS group and 5.3 cm (AUC 0.75) and 73.7 Gy (AUC 0.78) in the group without CS, respectively. However, though the local control of CT-based IGBT was favorable, the results suggested that the dose required for tumor control may differ depending on the presence of CS
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