139 research outputs found

    Seizure-Like Activities during Head-Up Tilt Test-Induced Syncope

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    Purpose: Some patients with neurally mediated reflex syncope may be misdiagnosed as epilepsy because myoclonic jerky movements are observed during syncope. The seizure-like activities during the head-up tilt test (HUT) have been rarely reported. The purpose of this study was to assess the characteristics of these seizure-like activities and evaluate whether there are differences in the clinical characteristics and hemodynamic parameters of patients with neurally mediated reflex syncope with and without seizure-like activities during HUT-induced syncope. Materials and Methods: The medical records of 1,383 consecutive patients with a positive HUT were retrospectively reviewed, and 226 patients were included in this study. Results: Of 226 patients, 13 (5.75%) showed seizure-like activities, with 5 of these (2.21%) having multifocal myoclonic jerky movements, 5 (2.21%) having focal seizurelike activity involving one extremity, and 3 (1.33%) having upward deviation of eye ball. Comparison of patients with and without seizure-like activities revealed no significant differences in terms of clinical variables and hemodynamic parameters during HUT. Conclusion: Seizure-like activities occurred occasionally during HUTinduced syncope in patients with neurally mediated reflex syncope. The seizure-like activities during HUT might not be related to the severity of the syncopal episodes or hemodynamic changes during HUT. Key Words: Neurally mediated reflex syncope, seizure-like activities, head-up tilt tes

    15-Deoxy-Δ12,14-ProstaglandinJ2 Regulates Dedifferentiation through Peroxisome Proliferator-Activated Receptor-γ-Dependent Pathway but Not COX-2 Expression in Articular Chondrocytes

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    Peroxisome proliferator-activated receptors-γ (PPAR-γ) is critical for phenotype determination at early differentiation stages of mesenchymal cells, whereas its physiological role is unclear. Therefore, we investigated the role of 15-deoxy-Δ12,14-prostaglandinJ2 (15d-PGJ2), the natural receptor ligand for PPAR-γ, on dedifferentiation and inflammatory responses, such as COX-2 expression and PGE2 production, in articular chondrocytes. Our data indicate that the 15d-PGJ2 caused a loss of differentiated chondrocyte phenotype as demonstrated by inhibition of type II collagen and proteoglycan synthesis. 15d-PGJ2 also induced COX-2 expression and PGE2 production. The 15d-PGJ2-induced dedifferentiation effect seems to be dependent on PPAR-γ activation, as the PPRE luciferase activity increased and PPAR-γ antagonist, BADGE, abolished type II collagen expression. However, BADGE did not block 15d-PGJ2-induced COX-2 expression. Collectively, our findings suggest that PPAR-γ-dependent and -independent mechanisms of 15d-PGJ2-induced dedifferentiation and inflammatory responses in articular chondrocytes, respectively. Additionally, these data suggest that targeted modulation of the PPAR-γ pathway may offer a novel approach for therapeutic inhibition of joint tissue degradation

    Berberine Improves Benign Prostatic Hyperplasia via Suppression of 5 Alpha Reductase and Extracellular Signal-Regulated Kinase in Vivo and in Vitro

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    Benign prostate hyperplasia (BPH) is a common disease in elderly men, characterized by proliferated prostate and urinary tract symptoms. The hormonal cascade starting by the action of 5-alpha-reductase (5AR) is known to be one of the pathways responsible for the pathogenesis of BPH. Present investigation evaluated the capacity of berberine (BBR), a nature-derived compound abundant in Coptis japonica, in testosterone-induced BPH rats. Experimental BPH was induced by inguinal injection with testosterone propionate (TP) for 4 weeks. BBR or finasteride, a 5AR inhibitor as positive control, was treated for 4 weeks during BPH. BPH induced by TP evoked weight gaining and histological changes of prostate and BBR treatment improved all the detrimental effects not only weight reduction and histological changes but also suppression of prostate-specific antigen (PSA), which is elevated during BPH. Additionally, BBR suppressed TP-associated increase of 5AR, androgen receptor (AR) and steroid coactivator-1 (SRC-1), the key factors in the pathogenesis of BPH. To evaluate the underlying molecular mechanisms responsible for beneficial effects of BBR, we investigated whether these effects were associated with the mitogen-activated protein kinase pathway. BPH induced by TP showed increased phosphorylation of extracellular signal-regulated kinase (ERK), whereas this was suppressed by BBR treatment. On the other hand, c-jun-N-terminal kinase (JNK) and p38 mitogen-activated protein kinase was not changed in BPH rats. In in vitro study using RWPE-1 cells, a human prostate epithelial cell line. TP increased cell proliferation and BPH-related key factors such as PSA, AR, and 5AR in RWPE-1 cells, and those factors were significantly decreased in the presence of BBR. Furthermore, these proliferative effects in RWPE-1cells were attenuated by treatment with U0126, an ERK inhibitor, confirming BBR can relieve overgrowth of prostate via ERK-dependent signaling. The cotreatment of U0126 and BBR did not affect the change of 5AR nor proliferation compared with U0126 alone, suggesting that the effect of BBR was dependent on the action of ERK. In conclusion, this study shows that BBR can be used as a therapeutic agent for BPH by controlling hyperplasia of prostate through suppression of ERK mechanism

    Determinants of redox sensitivity in RsrA, a zinc-containing anti-sigma factor for regulating thiol oxidative stress response

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    Various environmental oxidative stresses are sensed by redox-sensitive regulators through cysteine thiol oxidation or modification. A few zinc-containing anti-sigma (ZAS) factors in actinomycetes have been reported to respond sensitively to thiol oxidation, among which RsrA from Streptomyces coelicolor is best characterized. It forms disulfide bonds upon oxidation and releases bound SigR to activate thiol oxidative stress response genes. Even though numerous ZAS proteins exist in bacteria, features that confer redox sensitivity to a subset of these have been uncharacterized. In this study, we identified seven additional redox-sensitive ZAS factors from actinomycetes. Comparison with redox-insensitive ZAS revealed characteristic sequence patterns. Domain swapping demonstrated the significance of the region K33FEHH37FEEC41SPC44LEK47 that encompass the conserved HX3CX2C (HCC) motif. Mutational effect of each residue on diamide responsive induction of SigR target genes in vivo demonstrated that several residues, especially those that flank two cysteines (E39, E40, L45, E46), contribute to redox sensitivity. These residues are well conserved among redox-sensitive ZAS factors, and hence are proposed as redox-determinants in sensitive ZAS. H37A, C41A, C44A and F38A mutations, in contrast, compromised SigR-binding activity significantly, apparently affecting structural integrity of RsrA. The residue pattern around HCC motif could therefore serve as an indicator to predict redox-sensitive ZAS factors from sequence information

    The RAV1 transcription factor positively regulates leaf senescence in Arabidopsis

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    Leaf senescence is a developmentally programmed cell death process that constitutes the final step of leaf development and involves the extensive reprogramming of gene expression. Despite the importance of senescence in plants, the underlying regulatory mechanisms are not well understood. This study reports the isolation and functional analysis of RAV1, which encodes a RAV family transcription factor. Expression of RAV1 and its homologues is closely associated with leaf maturation and senescence. RAV1 mRNA increased at a later stage of leaf maturation and reached a maximal level early in senescence, but decreased again during late senescence. This profile indicates that RAV1 could play an important regulatory role in the early events of leaf senescence. Furthermore, constitutive and inducible overexpression of RAV1 caused premature leaf senescence. These data strongly suggest that RAV1 is sufficient to cause leaf senescence and it functions as a positive regulator in this process

    The disruption of proteostasis in neurodegenerative diseases

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    Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio
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