408 research outputs found

    Absorption and Fluorescence Spectra of 10-Hydroxy-benzo [h] quinoline and 10-Methoxy-benzo [h] quinoline in various Solvents

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    Article信州大学工学部紀要 73: 39-48 (1993)departmental bulletin pape

    Region-Specific Neuroprotective Features of Astrocytes against Oxidative Stress Induced by 6-Hydroxydopamine

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    In previous studies, we found regional differences in the induction of antioxidative molecules in astrocytes against oxidative stress, postulating that region-specific features of astrocytes lead region-specific vulnerability of neurons. We examined region-specific astrocytic features against dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) as an oxidative stress using co-culture of mesencephalic neurons and mesencephalic or striatal astrocytes in the present study. The 6-OHDA-induced reduction of mesencephalic dopamine neurons was inhibited by co-culturing with astrocytes. The co-culture of midbrain neurons with striatal astrocytes was more resistant to 6-OHDA than that with mesencephalic astrocytes. Furthermore, glia conditioned medium from 6-OHDA-treated striatal astrocytes showed a greater protective effect on the 6-OHDA-induced neurotoxicity and oxidative stress than that from mesencephalic astrocytes. The cDNA microarray analysis showed that the number of altered genes in both mesencephalic and striatal astrocytes was fewer than that changed in either astrocyte. The 6-OHDA treatment, apparently up-regulated expressions of Nrf2 and some anti-oxidative or Nrf2-regulating phase II, III detoxifying molecules related to glutathione synthesis and export in the striatal astrocytes but not mesencephalic astrocytes. There is a profound regional difference of gene expression in astrocytes induced by 6-OHDA. These results suggest that protective features of astrocytes against oxidative stress are more prominent in striatal astrocytes, possibly by secreting humoral factors in striatal astrocytes

    Experimental Research on Performances of Air Turbines for a Fixed Oscillating Water Column-Type Wave Energy Converter

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    A fixed oscillating water column (OWC)-type wave energy converter is composed of an air chamber for primary conversion and an air turbine for secondary conversion. In the optimal design method of a fixed OWC-type wave energy converter, it is necessary to develop a design method which can consider the characteristics of incident wave motion, the motion of the internal free surface affected in the structure such as a partly submerged wall, the fluctuation of air pressure in an air chamber, the rotation of the air turbine. In this paper, the 2-dimensional wave tank tests in regular waves for the performance evaluation of the air turbines in a fixed OWC-type wave energy converter were conducted to obtain the data needed to make this design method. As the results, the effects of the impulse turbine specification such as the rotor inlet/outlet angle, the guide vane's number and the vane's setting angle on the primary and secondary conversion efficiencies are clarified experimentally. Furthermore, the performances of the Wells turbines with different number of blade are presented for comparison of the operating condition

    Kohn anomalies in graphene nanoribbons

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    The quantum corrections to the energies of the Γ\Gamma point optical phonon modes (Kohn anomalies) in graphene nanoribbons are investigated. We show theoretically that the longitudinal optical modes undergo a Kohn anomaly effect, while the transverse optical modes do not. In relation to Raman spectroscopy, we show that the longitudinal modes are not Raman active near the zigzag edge, while the transverse optical modes are not Raman active near the armchair edge. These results are useful for identifying the orientation of the edge of graphene nanoribbons by G band Raman spectroscopy, as is demonstrated experimentally. The differences in the Kohn anomalies for nanoribbons and for metallic single wall nanotubes are pointed out, and our results are explained in terms of pseudospin effects.Comment: 11 pages, 6 figure

    Mirtazapine exerts astrocyte-mediated dopaminergic neuroprotection

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    Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson's disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD

    E22Δ Mutation in Amyloid β-Protein Promotes β-Sheet Transformation, Radical Production, and Synaptotoxicity, But Not Neurotoxicity

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    Oligomers of 40- or 42-mer amyloid β-protein (Aβ40, Aβ42) cause cognitive decline and synaptic dysfunction in Alzheimer's disease. We proposed the importance of a turn at Glu22 and Asp23 of Aβ42 to induce its neurotoxicity through the formation of radicals. Recently, a novel deletion mutant at Glu22 (E22Δ) of Aβ42 was reported to accelerate oligomerization and synaptotoxicity. To investigate this mechanism, the effects of the E22Δ mutation in Aβ42 and Aβ40 on the transformation of β-sheets, radical production, and neurotoxicity were examined. Both mutants promoted β-sheet transformation and the formation of radicals, while their neurotoxicity was negative. In contrast, E22P-Aβ42 with a turn at Glu22 and Asp23 exhibited potent neurotoxicity along with the ability to form radicals and potent synaptotoxicity. These data suggest that conformational change in E22Δ-Aβ is similar to that in E22P-Aβ42 but not the same, since E22Δ-Aβ42 exhibited no cytotoxicity, unlike E22P-Aβ42 and wild-type Aβ42

    The Risk of Cytotoxic Chemotherapy-Related Exacerbation of Interstitial Lung Disease with Lung Cancer

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    IntroductionIt is unknown what type of interstitial lung disease (ILD) has high risk for chemotherapy-related exacerbation of ILD. We investigated the risk of exacerbation of ILD for patients with lung cancer with ILD.MethodsOne hundred nine patients with lung cancer with ILD treated with cytotoxic chemotherapy at Shizuoka Cancer Center between August 2002 and April 2010 were retrospectively reviewed.ResultsOn pretreatment computed tomography (CT) of the chest, 69 patients (63%) were identified with usual interstitial pneumonia (UIP) pattern, and 40 patients (37%) had non-UIP pattern. Patients with UIP pattern developed cytotoxic chemotherapy-related exacerbation of ILD more frequently than those with non-UIP pattern (30 versus 8%, p = 0.005). The incidence of grade 5 pulmonary toxicities was 9% in patients with UIP pattern, compared with 3% in those with non-UIP pattern. Multivariate analyses demonstrated that age (<70 years) and CT pattern (UIP) were significant independent risk factors for cytotoxic chemotherapy-related exacerbation of ILD. In small cell lung cancer, overall survival (OS) from the start of first-line chemotherapy was significantly shorter in UIP pattern than non-UIP pattern (median OS: 9 versus 16 months, p = 0.0475), whereas there was no significant difference in patients with non-small cell lung cancer (median OS: 12 versus 9 months, p = 0.2529).ConclusionsOur results indicated that the incidence of exacerbation of ILD was significantly higher in patients with lung cancer with UIP pattern on CT findings than in those with non-UIP pattern. Therefore, great care is required when administering cytotoxic chemotherapy agents for patients with lung cancer with UIP pattern

    Biologic markers in prostatic intraepithelial neoplasia: immunohistochemical and cytogenetic analyses

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    Objective:We evaluated the biological properties of High-grade prostatic intraepithelial neoplasia (PIN) by immunohistochemistry and fluorescence in situ hybridization (FISH) analysis in relation to normal tissue and carcinoma lesions. Materials and Methods:Immunohistochemical staining and FISH were performed on23formalin-fixed radical prostatectomy specimens taken from patients with PIN. Assays were performed using MIB-1, chromogranin A (CGA) and an anti-androgen receptor antibody (AR). A centromere probe for chromosome8was used to test for aneuploidy. Results:The MIB-1index of cancerous specimens (16.2±10.5%) was significantly higher than that of benign (1.9±1.6%, p<0.0001) or PIN (4.0±4.5%, p<0.0001) specimens. The percentage of CGA positive cells was significantly lower in normal tissue (1.2±1.8%) than in PIN (3.5±2.9%, p=0.012) or carcinoma (5.4±4.9%, p=0.005) lesions. Positive staining for AR was consistently observed in the nuclei of both benign and malignant epithelial cells, but positive cytoplasmic staining was also seen in PIN epithelial cells. No significant difference in FISH detected anomalies were found between PIN and carcinoma specimens. Conclusions:Our studies concerning proliferative activity, NE differentiation and chromosomal anomalies of prostatic specimens support the hypothesis that PIN is a biologically intermediate stage in the pathogenesis of prostatic carcinoma. The cellular distribution of AR was altered in PIN cells, but the role of AR in PIN is not yet clear
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