275 research outputs found

    Cyclic Voltammetry of Phthalocyanines

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    Phthalocyanines and their related compounds possess similar structures as porphyrins. They have been used as green to blue dyes and pigments since their discovery. In this decade, they are known to be utilized in important functional colorants for many fields such as catalyst, laser light absorbers in data storage systems, electro-charge carriers in photocopies, photo-antenna device in photosynthesis, photovoltaic cells and photosensitizers for dye-sensitized solar cells (DSSCs), and photodynamic therapy of cancer (PDT). The functions are attributed to high electron transfer abilities of phthalocyanines. Cyclic voltammograms were carried out for phthalocyanines in order to estimate their electron transfer abilities and electrochemical mechanism

    Over-expression of cbaAB genes of Bacillus stearothermophilus produces a two-subunit SoxB-type cytochrome c oxidase with proton pumping activity

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    AbstractWe constructed expression plasmids containing cbaAB, the structural genes for the two-subunit cytochrome bo3-type cytochrome c oxidase (SoxB type) recently isolated from a Gram-positive thermophile Bacillus stearothermophilus.B. stearothermophilus cells transformed with the plasmids over-expressed an enzymatically active bo3-type cytochrome c oxidase protein composed of the two subunits, while the transformed Escherichia coli cells produced an inactive protein composed of subunit I without subunit II. The oxidase over-expressed in B. stearothermophilus was solubilized and purified. The oxidase contained protoheme IX and heme O, as the main low-spin heme and the high-spin heme, respectively. Analysis of the substrate specificity indicated that the high-affinity site is very specific for cytochrome c-551, a cytochrome c that is a membrane-bound lipoprotein of thermophilic Bacillus. The purified enzyme reconstituted into liposomal vesicles with cytochrome c-551 showed H+ pumping activity, although the efficiency was lower than those of cytochrome aa3-type oxidases belonging to the SoxM-type

    Variation of pro‐vasopressin processing in parvocellular and magnocellular neurons in the paraventricular nucleus of the hypothalamus: Evidence from the vasopressin‐related glycopeptide copeptin

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    Arginine vasopressin (AVP) is synthesized in parvocellular‐ and magnocellular neuroendocrine neurons in the paraventricular nucleus (PVN) of the hypothalamus. Whereas magnocellular AVP neurons project primarily to the posterior pituitary, parvocellular AVP neurons project to the median eminence (ME) and to extrahypothalamic areas. The AVP gene encodes pre‐pro‐AVP that comprises the signal peptide, AVP, neurophysin (NPII), and a copeptin glycopeptide. In the present study, we used an N‐terminal copeptin antiserum to examine copeptin expression in magnocellular and parvocellular neurons in the hypothalamus in the mouse, rat, and macaque monkey. Although magnocellular NPII‐expressing neurons exhibited strong N‐terminal copeptin immunoreactivity in all three species, a great majority (~90%) of parvocellular neurons that expressed NPII was devoid of copeptin immunoreactivity in the mouse, and in approximately half (~53%) of them in the rat, whereas in monkey hypothalamus, virtually all NPII‐immunoreactive parvocellular neurons contained strong copeptin immunoreactivity. Immunoelectron microscopy in the mouse clearly showed copeptin‐immunoreactivity co‐localized with NPII‐immunoreactivity in neurosecretory vesicles in the internal layer of the ME and posterior pituitary, but not in the external layer of the ME. Intracerebroventricular administration of a prohormone convertase inhibitor, hexa‐d‐arginine amide resulted in a marked reduction of copeptin‐immunoreactivity in the NPII‐immunoreactive magnocellular PVN neurons in the mouse, suggesting that low protease activity and incomplete processing of pro‐AVP could explain the disproportionally low levels of N‐terminal copeptin expression in rodent AVP (NPII)‐expressing parvocellular neurons. Physiologic and phylogenetic aspects of copeptin expression among neuroendocrine neurons require further exploration

    Peritumoral radiomics features on preoperative thin-slice CT images can predict the spread through air spaces of lung adenocarcinoma

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    The spread through air spaces (STAS) is recognized as a negative prognostic factor in patients with early-stage lung adenocarcinoma. The present study aimed to develop a machine learning model for the prediction of STAS using peritumoral radiomics features extracted from preoperative CT imaging. A total of 339 patients who underwent lobectomy or limited resection for lung adenocarcinoma were included. The patients were randomly divided (3:2) into training and test cohorts. Two prediction models were created using the training cohort: a conventional model based on the tumor consolidation/tumor (C/T) ratio and a machine learning model based on peritumoral radiomics features. The areas under the curve for the two models in the testing cohort were 0.70 and 0.76, respectively ( = 0.045). The cumulative incidence of recurrence (CIR) was significantly higher in the STAS high-risk group when using the radiomics model than that in the low-risk group (44% vs. 4% at 5 years;  = 0.002) in patients who underwent limited resection in the testing cohort. In contrast, the 5-year CIR was not significantly different among patients who underwent lobectomy (17% vs. 11%;  = 0.469). In conclusion, the machine learning model for STAS prediction based on peritumoral radiomics features performed better than the C/T ratio model

    Studies on metal-ion complex formation of crown ether derivatives incorporating a photoionizable spirobenzopyran moiety by electrospray ionization mass spectrometry

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    Metal-ion complexation of crown ether derivatives incorporating one and two spirobenzopyran units was investigated by electrospray ionization mass spectrometry.The crowned spirobenzopyran derivatives exhibited very different metal ion-complexing behavior from their corresponding parent crown ether rings,preferring multivalent to monovalent metal ions owing to the additional ionic interaction with the nitrophenolate anion of the merocyanine moiety.The on-line photochemical reaction for mass spectrometry indicated that the metal ion-complexing ability and ion selectivities of the crowned spirobenzopyrans can be switched photochemically,taking advantage of the difference between the spiropyran and merocyanine isomers

    若年性乳腺線維腺腫

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    A 12-year-old, premenarchal girl with a rapidly growing breast lump was transferred to our hospital. Ultrasonography revealed a 7.9×7.7×3.3cm large well-circumscribed hypoechoic tumor in the medial region of her right breast. After 2 months of this first visit, the breast lump had enlarged to10 cm in diameter and was consequently subjected to a wide excision. Size of the tumor was9.5×9.2×3.0cm. Histopathological diagnosis was fibroadenoma without any malignant component. One year after the operation, a new lump with a diameter of4cm was detected in the lateral region of her right breast that had a similar appearance of the previous tumor. The tumor was excised as earlier and diagnosed as fibroadenoma. We present an extremely rare case of a rapidly growing breast fibroadenoma in a premenarchal girl. To the best of our knowledge, there were only 21 cases reported in Japan. Since the patient is concerned that another asynchronous fibroadenoma might occur, she needs a long-term and careful follow-up

    The effect of pegylated interferon-alpha2b and ribavirin combination therapy for chronic hepatitis C infection in elderly patients

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    <p>Abstract</p> <p>Background</p> <p>The clearance of hepatitis C virus infection by interferon therapy significantly reduces the incidence of hepatocellular carcinoma and death in elderly chronic hepatitis patients. However, there are few reports concerning the efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients. The aims of the present study were to examine the effect and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in 427 patients with chronic hepatitis C infection. We compared the rates of sustained virological response--defined as the absence of detectable hepatitis C virus in serum 24 weeks after the treatment ended--and the treatment discontinuation rate between 319 younger patients aged < 65 years and 108 elderly patients aged ≥ 65 years. We also examined the factors contributing to a sustained virological response.</p> <p>Results</p> <p>There was no significant difference in the sustained virological response rate between younger patients and elderly patients according to their hepatitis C virus genotype (41.5% (100/241) and 40.7% (35/86) for genotype 1; <it>P </it>= 0.899, 89.7% (70/78) and 86.4% (19/22) for genotype 2; <it>P </it>= 0.703, respectively). There was also no significant difference in the treatment discontinuation rate between the two age groups (10.3% (33/319) and 13.9% (15/108), respectively; <it>P </it>= 0.378). There were no serious adverse events requiring hospitalization. The factors contributing significantly to a sustained virological response in elderly patients were gender, hepatitis C virus genotype, platelet count, and the presence of a rapid or early virological response (undetectable hepatitis C virus in serum at weeks 4 or 12 of treatment, respectively). However, upon multivariate analysis, the presence of an early virological response was the only significant factor (odds ratio: 0.115, 95% confidence interval: 0.040- 0.330, <it>P </it>< 0.001).</p> <p>Conclusions</p> <p>The efficacy and safety of pegylated interferon-alpha2b plus ribavirin combination therapy in elderly patients are not always inferior to those in younger patients. Obtaining an early virological response may be essential to achieve a sustained virological response in elderly patients with chronic hepatitis C infection.</p

    ADAMTS13 gene deletion enhances plasma high-mobility group box1 elevation and neuroinflammation in brain ischemia-reperfusion injury

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    Highly adhesive glycoprotein von Willebrand factor (VWF) multimer induces platelet aggregation and leukocyte tethering or extravasation on the injured vascular wall, contributing to microvascular plugging and inflammation in brain ischemia-reperfusion. A disintegrin and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) cleaves the VWF multimer strand and reduces its prothrombotic and proinflammatory functions. Although ADAMTS13 deficiency is known to amplify post-ischemic cerebral hypoperfusion, there is no report available on the effect of ADAMTS13 on inflammation after brain ischemia. We investigated if ADAMTS13 deficiency intensifies the increase of extracellular HMGB1, a hallmark of post-stroke inflammation, and exacerbates brain injury after ischemia-reperfusion. ADAMTS13 gene knockout (KO) and wild-type (WT) mice were subjected to 30-min middle cerebral artery occlusion (MCAO) and 23.5-h reperfusion under continuous monitoring of regional cerebral blood flow (rCBF). The infarct volume, plasma high-mobility group box1 (HMGB1) level, and immunoreactivity of the ischemic cerebral cortical tissue (double immunofluorescent labeling) against HMGB1/NeuN (neuron-specific nuclear protein) or HMGB1/MPO (myeloperoxidase) were estimated 24h after MCAO. ADAMTS13KO mice had larger brain infarcts compared with WT 24h after MCAO (p<0.05). The rCBF during reperfusion decreased more in ADAMTS13KO mice. The plasma HMGB1 increased more in ADAMTS13KO mice than in WT after ischemia-reperfusion (p<0.05). Brain ischemia induced more prominent activation of inflammatory cells co-expressing HMGB1 and MPO and more marked neuronal death in the cortical ischemic penumbra of ADAMTS13KO mice. ADAMTS13 deficiency may enhance systemic and brain inflammation associated with HMGB1 neurotoxicity, and aggravate brain damage in mice after brief focal ischemia. We hypothesize that ADAMTS13 protects brain from ischemia-reperfusion injury by regulating VWF-dependent inflammation as well as microvascular pluggin
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