50 research outputs found

    Alterations in IL-6, IL-8, GM-CSF. TNF-α, and IFN-γ Release by Peripheral Mononuclear Cells in Patients with Active Vitiligo

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    The purpose of this study was to clarify the relationship between the cellular and humoral immune components in the pathogenesis of vitiligo vulgaris. By using cytokines as indicators of peripheral mononuclear cell (MNC) function, we compared the effects of phytohemagglutinin (PHA) and purified IgG on MNCs derived from patients suffering from active vitiligo with those from normal controls. The results revealed (i) a significant increase in spontaneous production of 11-6 and IL-8 in patients; (ii) PHA, purified IgG from patients (IgG-anti-MC), or IgG from normal controls (N-IgG) induced a significant increase in IL-6 but diminished GM-CSF, TNF-α, and IFN-γ release in patients; and (iii) IgG-anti-MC brought about a significantly higher stimulatory effect on IL-1β and IFN-γ production than N-IgG in normal controls. Immunologically, IL-6 can enhance melanocyte ICAM-1 expression, which may increase leukocyte-melanocyte attachment and cause melanocyte damage in vitiligo. A decrease in GM-CSF (an intrinsic growth factor for melanocyte) production may retard recovery from vitiligo by checking the proliferation of surviving melanocytes. A significant decrease in TNF-α and IFN-γ production may partially explain the reduced inflammatory reaction in vitiliginous lesions. That IgG-anti-MC stimulates an increase in IL-1β and IFN-γ production in controls suggests that IgG-anti-MC may play a role in melanocyte destruction mediated by monocytes

    A Study on Tunneling Current of ONO Films and Data Retention Effects in Flash Memories

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    Abstract In this research, 5 different thicknesses of oxide-nitride-oxide (ONO) inter-poly-gate dielectrics in flash memories are studied. Besides the experiments of analyzing program/erase speeds, various I-V tests have also being conducted to understand the tunneling characteristics of these ONO films. Data retention effects are also investigated by measuring the threshold voltage shifts consecutively up to 200 h of 250EC baking. All the findings are analyzed and concluded to propose a set of ONO film scaling rules

    Narrow-Band Ultraviolet-B Stimulates Proliferation and Migration of Cultured Melanocytes

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    Narrow-band ultraviolet-B (UVB) radiation is an effective treatment for vitiligo vulgaris. However, the mechanisms of narrow-band UVB in inducing repigmentation of vitiligo lesions are not thoroughly clarified. The purpose of our study was to investigate the effects of narrow-band UVB irradiation on melanocyte proliferation and migration in vitro. Our results showed that the cell counts as well as [3 H]thymidine uptake of melanocytes were significantly enhanced by narrow-band UVB-irradiated keratinocyte supernatants. In these supernatants, a significant increase in basic fibroblast growth factor (bFGF) and in endothelin-1 (ET-1) release was observed. bFGF is a natural mitogen for melanocytes, whereas ET-1 can stimulate DNA synthesis in melanocytes. This stimulatory effect of melanocyte proliferation by supernatants derived from narrow-band UVB- irradiated keratinocytes was significantly reduced by a selective endothelin-B (ET-B) receptor antagonist (BQ788), suggesting an essential role of ET-1 on melanocyte proliferation. Our results of time-lapse microphotography revealed a stimulatory effect of narrow-band UVB irradiation on melanocyte migration. Focal adhesion kinase (FAK) plays a pivotal role in cell migration. Phosphorylated FAK (p125( FAK)) expression on melanocyte was enhanced by narrow-band UVB irradiation. In this study, narrow-band UVB irradiation stimulated a significant increase in matrix metalloproteinase-2 (MMP-2) activity in melanocyte supernatants. Narrow- band UVB-irradiation-induced migration of melanocytes was significantly annihilated by the addition of p125(FAK) inhibitor (herbimycin-A) or MMP-2 inhibitor ( GM6001). These results suggest that p125(FAK) and MMP-2 activity play important roles in narrow-band UVB-induced migration of melanocytes. Our results provide a theoretical basis for the effectiveness of narrow-band UVB irradiation in treating vitiligo

    Dose-Dependent Effect of Hyperbaric Oxygen Treatment on Burn-Induced Neuropathic Pain in Rats

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    Hyperbaric oxygen treatment (HBOT) has been used to reduce neuropathic pain. Melatonin and opioid receptors are involved in neuropathic pain, but it is not known if HBOT works through these pathways to achieve its antinociceptive effect. We divided anesthetized rats into two treatment and three sham groups. The two treatment groups received third-degree burns on their right hind paws, one treated in a hyperbaric chamber for a week and the other for two weeks. We evaluated the mechanical paw-withdrawal threshold (MWT) and expression of melatonin receptor 1 (MT1), melatonin receptor 2 (MT2), μ (MOR) and κ (KOR) opioid receptor, brain-derived neurotrophic factor (BDNF), Substance P, and calcitonin gene-related peptide (CGRP) in cuneate nucleus, dorsal horn, and hind paw skin by immunohistochemical, immunofluorescence assays and real-time quantitative polymerase chain reaction (RT-PCR). The group receiving one-week HBOT had increased expressions of MT1, MT2, MOR and KOR and decreased expressions of BDNF, Substance P, and CGRP. Their mechanically measured pain levels returned to normal within a week and lasted three weeks. This anti-allodynia effect lasted twice as long in those treated for two weeks. Our findings suggest that increasing the duration of HBOT can reduce burn-induced mechanical allodynia for an extended period of time in rats. The upregulation of melatonin and opioid receptors observed after one week of HBOT suggests they may be partly involved in attenuation of the mechanical allodynia. Downregulation of BDNF, substance P and CGRP may have also contributed to the overall beneficial effect of HBOT

    The Prevalence of Subclinical Thyroid Dysfunction and Its Association With Metabolic Syndrome in Taiwanese Elderly

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    Background: The pathophysiology of thyroid function on lipid and glucose metabolism and blood pressure for subjects with thyroid disorder is well known; however, studies exploring the association between thyroid function and components of metabolic syndrome (MetS) in elderly subjects with subclinical thyroid dysfunction are limited. Our objectives were to investigate the prevalence of subclinical thyroid dysfunction among the elderly and its relationship with MetS in Taiwan. Methods: A total of 6,652 subjects aged 65 years or older were recruited during a routine health checkup at four MJ Health Screening Centers in Taiwan. Gender; blood pressure; body mass index; and serum levels of fasting glucose, total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C), low-density-lipoprotein cholesterol, and triglyceride were compared between subjects with subclinical hypothyroidism and hyperthyroidism. Results: The overall prevalences of the MetS, subclinical hyperthyroidism, and subclinical hypothyroidism were 30.4%, 6.0%, and 2.0%, respectively. The prevalence of subclinical thyroid dysfunction was significantly higher among women as compared with men (9.9% vs. 6.3%, respectively; p<0.05). Male subjects with subclinical hyperthyroidism had significantly lower body mass index, systolic blood pressure, TC, low-density-lipoprotein cholesterol, HDL-C, triglyceride, and number of MetS criteria than female subjects. However, no significant differences for each component of MetS, with the exception of TC and HDL-C, were found between male and female subjects with subclinical hypothyroidism. Conclusion: Subclinical thyroid dysfunction would present in about 8% of Taiwanese elderly, and about one-third of them had MetS

    Characteristics of pulmonary artery strain assessed by cardiovascular magnetic resonance imaging and associations with metabolomic pathways in human ageing

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    BackgroundPulmonary artery (PA) strain is associated with structural and functional alterations of the vessel and is an independent predictor of cardiovascular events. The relationship of PA strain to metabolomics in participants without cardiovascular disease is unknown.MethodsIn the current study, community-based older adults, without known cardiovascular disease, underwent simultaneous cine cardiovascular magnetic resonance (CMR) imaging, clinical examination, and serum sampling. PA global longitudinal strain (GLS) analysis was performed by tracking the change in distance from the PA bifurcation to the pulmonary annular centroid, using standard cine CMR images. Circulating metabolites were measured by cross-sectional targeted metabolomics analysis.ResultsAmong n = 170 adults (mean age 71 ± 6.3 years old; 79 women), mean values of PA GLS were 16.2 ± 4.4%. PA GLS was significantly associated with age (β = −0.13, P = 0.017), heart rate (β = −0.08, P = 0.001), dyslipidemia (β = −2.37, P = 0.005), and cardiovascular risk factors (β = −2.49, P = 0.001). Alanine (β = −0.007, P = 0.01) and proline (β = −0.0009, P = 0.042) were significantly associated with PA GLS after adjustment for clinical risk factors. Medium and long-chain acylcarnitines were significantly associated with PA GLS (C12, P = 0.027; C12-OH/C10-DC, P = 0.018; C14:2, P = 0.036; C14:1, P = 0.006; C14, P = 0.006; C14-OH/C12-DC, P = 0.027; C16:3, P = 0.019; C16:2, P = 0.006; C16:1, P = 0.001; C16:2-OH, P = 0.016; C16:1-OH/C14:1-DC, P = 0.028; C18:1-OH/C16:1-DC, P = 0.032).ConclusionBy conventional CMR, PA GLS was associated with aging and vascular risk factors among a contemporary cohort of older adults. Metabolic pathways involved in PA stiffness may include gluconeogenesis, collagen synthesis, and fatty acid oxidation

    Zwitterionic Palladium Complexes: Room-Temperature Suzuki–Miyaura Cross-Coupling of Sterically Hindered Substrates in an Aqueous Medium

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    A series of new imidazolium chlorides were straightforwardly prepared from the reactions between chloroacetone and imidazole derivatives. Deprotonation of the methylene proton next to the ketone group in these salts by pyridine led to the formation of a monodentate ligand that coordinated to palladium, readily forming zwitterionic anionic palladium pyridine complexes bearing a formal positive charge on the ligand ancillary. The pyridine ligand in the zwitterionic complexes can be facilely replaced by phosphine ligands. Seven of these new complexes were successfully characterized by X-ray crystallography. The zwitterionic phosphine complexes were highly efficient in catalyzing room-temperature Suzuki–Miyaura reactions between sterically hindered aryl chlorides and arylboronic acids in an aqueous medium
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