40 research outputs found

    Diffusion tensor imaging with direct cytopathological validation: Characterisation of decorin treatment in experimental juvenile communicating hydrocephalus

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    BACKGROUND: In an effort to develop novel treatments for communicating hydrocephalus, we have shown previously that the transforming growth factor-β antagonist, decorin, inhibits subarachnoid fibrosis mediated ventriculomegaly; however decorin’s ability to prevent cerebral cytopathology in communicating hydrocephalus has not been fully examined. Furthermore, the capacity for diffusion tensor imaging to act as a proxy measure of cerebral pathology in multiple sclerosis and spinal cord injury has recently been demonstrated. However, the use of diffusion tensor imaging to investigate cytopathological changes in communicating hydrocephalus is yet to occur. Hence, this study aimed to determine whether decorin treatment influences alterations in diffusion tensor imaging parameters and cytopathology in experimental communicating hydrocephalus. Moreover, the study also explored whether diffusion tensor imaging parameters correlate with cellular pathology in communicating hydrocephalus. METHODS: Accordingly, communicating hydrocephalus was induced by injecting kaolin into the basal cisterns in 3-week old rats followed immediately by 14 days of continuous intraventricular delivery of either human recombinant decorin (n = 5) or vehicle (n = 6). Four rats remained as intact controls and a further four rats served as kaolin only controls. At 14-days post-kaolin, just prior to sacrifice, routine magnetic resonance imaging and magnetic resonance diffusion tensor imaging was conducted and the mean diffusivity, fractional anisotropy, radial and axial diffusivity of seven cerebral regions were assessed by voxel-based analysis in the corpus callosum, periventricular white matter, caudal internal capsule, CA1 hippocampus, and outer and inner parietal cortex. Myelin integrity, gliosis and aquaporin-4 levels were evaluated by post-mortem immunohistochemistry in the CA3 hippocampus and in the caudal brain of the same cerebral structures analysed by diffusion tensor imaging. RESULTS: Decorin significantly decreased myelin damage in the caudal internal capsule and prevented caudal periventricular white matter oedema and astrogliosis. Furthermore, decorin treatment prevented the increase in caudal periventricular white matter mean diffusivity (p = 0.032) as well as caudal corpus callosum axial diffusivity (p = 0.004) and radial diffusivity (p = 0.034). Furthermore, diffusion tensor imaging parameters correlated primarily with periventricular white matter astrocyte and aquaporin-4 levels. CONCLUSIONS: Overall, these findings suggest that decorin has the therapeutic potential to reduce white matter cytopathology in hydrocephalus. Moreover, diffusion tensor imaging is a useful tool to provide surrogate measures of periventricular white matter pathology in communicating hydrocephalus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12987-016-0033-2) contains supplementary material, which is available to authorized users

    ILB® resolves inflammatory scarring and promotes functional tissue repair

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    Fibrotic disease is a major cause of mortality worldwide, with fibrosis arising from prolonged inflammation and aberrant extracellular matrix dynamics. Compromised cellular and tissue repair processes following injury, infection, metabolic dysfunction, autoimmune conditions and vascular diseases leave tissues susceptible to unresolved inflammation, fibrogenesis, loss of function and scarring. There has been limited clinical success with therapies for inflammatory and fibrotic diseases such that there remains a large unmet therapeutic need to restore normal tissue homoeostasis without detrimental side effects. We investigated the effects of a newly formulated low molecular weight dextran sulfate (LMW-DS), termed ILB®, to resolve inflammation and activate matrix remodelling in rodent and human disease models. We demonstrated modulation of the expression of multiple pro-inflammatory cytokines and chemokines in vitro together with scar resolution and improved matrix remodelling in vivo. Of particular relevance, we demonstrated that ILB® acts, in part, by downregulating transforming growth factor (TGF)β signalling genes and by altering gene expression relating to extracellular matrix dynamics, leading to tissue remodelling, reduced fibrosis and functional tissue regeneration. These observations indicate the potential of ILB® to alleviate fibrotic diseases

    A Study on the Real Estate Mortgage System in China-The Present Conditions and Problems of the Real Estate Mortgage-

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    本研究は、中国の不動産担保法制度の現状に対して、立法及び学説を検討し、不動産担保法制度のあり方を明らかにすることを目的とする。そのため、中国の不動産担保法制度の歴史変革を概観し、現行法上の不動産抵当権の概念、類型、設定及び公示制度を中心として、中国における不動産抵当権制度の現状と課題について考察する。特に、都市部における未完成建物の抵当権制度、農村における家屋の抵当権制度、抵当物の価値と被担保債権額の関係問題、不動産抵当権の公示制度などの課題を明らかにしたい

    Evaluating the fat distribution in Idiopathic Intracranial Hypertension using Dual energy X-ray absorptiometry scanning

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    Idiopathic intracranial hypertension (IIH) is strongly associated with obesity. We aimed to utilise dual-energy X-ray absorptiometry (DEXA) to characterise fat distribution, and to evaluate change in fat mass and distribution following weight loss. IIH patients (n = 24) had a similar fat distribution to body mass index (BMI)- and gender-matched obese controls (n = 47). In the IIH cohort, truncal fat mass correlated with lumbar puncture pressure. Weight loss in IIH patients resulted in a significant reduction in disease activity and fat mass, predominantly from the truncal region (-4.40 ± 1.6%; p = 0.008) compared with the limbs (+0.79 ± 6.5%; p = 0.71). These results indicate that, contrary to previous studies using waist-hip ratios, IIH adiposity is centripetal, similar to simple obesity. Future studies should establish the risk of the metabolic syndrome and the role of adipose tissue depot-specific function in IIH

    Topiramate is more effective than acetazolamide at lowering intracranial pressure

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    BACKGROUND The management of idiopathic intracranial hypertension focuses on reducing intracranial pressure to preserve vision and reduce headaches. There is sparse evidence to support the use of some of the drugs commonly used to manage idiopathic intracranial hypertension, therefore we propose to evaluate the efficacy of these drugs at lowering intracranial pressure in healthy rats. METHODS We measured intracranial pressure in female rats before and after subcutaneous administration of acetazolamide, topiramate, furosemide, amiloride and octreotide at clinical doses (equivalent to a single human dose) and high doses (equivalent to a human daily dose). In addition, we measured intracranial pressure after oral administration of acetazolamide and topiramate. RESULTS At clinical and high doses, subcutaneous administration of topiramate lowered intracranial pressure by 32% ( p = 0.0009) and 21% ( p = 0.015) respectively. There was no significant reduction in intracranial pressure noted with acetazolamide, furosemide, amiloride or octreotide at any dose. Oral administration of topiramate significantly lowered intracranial pressure by 22% ( p = 0.018), compared to 5% reduction with acetazolamide ( p = >0.999). CONCLUSION Our in vivo studies demonstrated that both subcutaneous and oral administration of topiramate significantly lowers intracranial pressure. Other drugs tested, including acetazolamide, did not significantly reduce intracranial pressure. Future clinical trials evaluating the efficacy and side effects of topiramate in idiopathic intracranial hypertension patients would be of interest

    Ecrg4 expression and its product augurin in the choroid plexus: impact on fetal brain development, cerebrospinal fluid homeostasis and neuroprogenitor cell response to CNS injury

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    <p>Abstract</p> <p>Background</p> <p>The content and composition of cerebrospinal fluid (CSF) is determined in large part by the choroid plexus (CP) and specifically, a specialized epithelial cell (CPe) layer that responds to, synthesizes, and transports peptide hormones into and out of CSF. Together with ventricular ependymal cells, these CPe relay homeostatic signals throughout the central nervous system (CNS) and regulate CSF hydrodynamics. One new candidate signal is augurin, a newly recognized 14 kDa protein that is encoded by <it>esophageal cancer related gene-4 </it>(<it>Ecrg4</it>), a putative tumor suppressor gene whose presence and function in normal tissues remains unexplored and enigmatic. The aim of this study was to explore whether <it>Ecrg4 </it>and its product augurin, can be implicated in CNS development and the response to CNS injury.</p> <p>Methods</p> <p><it>Ecrg4 </it>gene expression in CNS and peripheral tissues was studied by <it>in situ </it>hybridization and quantitative RT-PCR. Augurin, the protein encoded by <it>Ecrg4</it>, was detected by immunoblotting, immunohistochemistry and ELISA. The biological consequence of augurin over-expression was studied in a cortical stab model of rat CNS injury by intra-cerebro-ventricular injection of an adenovirus vector containing the <it>Ecrg4 </it>cDNA. The biological consequences of reduced augurin expression were evaluated by characterizing the CNS phenotype caused by <it>Ecrg4 </it>gene knockdown in developing zebrafish embryos.</p> <p>Results</p> <p>Gene expression and immunohistochemical analyses revealed that, the CP is a major source of <it>Ecrg4 </it>in the CNS and that <it>Ecrg4 </it>mRNA is predominantly localized to choroid plexus epithelial (CPe), ventricular and central canal cells of the spinal cord. After a stab injury into the brain however, both augurin staining and <it>Ecrg4 </it>gene expression decreased precipitously. If the loss of augurin was circumvented by over-expressing <it>Ecrg4 in vivo</it>, BrdU incorporation by cells in the subependymal zone decreased. Inversely, gene knockdown of <it>Ecrg4 </it>in developing zebrafish embryos caused increased proliferation of GFAP-positive cells and induced a dose-dependent hydrocephalus-like phenotype that could be rescued by co-injection of antisense morpholinos with <it>Ecrg4 </it>mRNA.</p> <p>Conclusion</p> <p>An unusually elevated expression of the <it>Ecrg4 </it>gene in the CP implies that its product, augurin, plays a role in CP-CSF-CNS function. The results are all consistent with a model whereby an injury-induced decrease in augurin dysinhibits target cells at the ependymal-subependymal interface. We speculate that the ability of CP and ependymal epithelium to alter the progenitor cell response to CNS injury may be mediated, in part by <it>Ecrg4</it>. If so, the canonic control of its promoter by DNA methylation may implicate epigenetic mechanisms in neuroprogenitor fate and function in the CNS.</p

    A unique androgen excess signature in idiopathic intracranial hypertension is linked to cerebrospinal fluid dynamics

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    Idiopathic intracranial hypertension (IIH) is a condition of unknown etiology, characterized by elevated intracranial pressure frequently manifesting with chronic headaches and visual loss. Similar to polycystic ovary syndrome (PCOS), IIH predominantly affects obese women of reproductive age. In this study, we comprehensively examined the systemic and cerebrospinal fluid (CSF) androgen metabolome in women with IIH in comparison with sex-, BMI-, and age-matched control groups with either simple obesity or PCOS (i.e., obesity and androgen excess). Women with IIH showed a pattern of androgen excess distinct to that observed in PCOS and simple obesity, with increased serum testosterone and increased CSF testosterone and androstenedione. Human choroid plexus expressed the androgen receptor, alongside the androgen-activating enzyme aldoketoreductase type 1C3. We show that in a rat choroid plexus cell line, testosterone significantly enhanced the activity of Na+/K+-ATPase, a surrogate of CSF secretion. We demonstrate that IIH patients have a unique signature of androgen excess and provide evidence that androgens can modulate CSF secretion via the choroid plexus. These findings implicate androgen excess as a potential causal driver and therapeutic target in IIH
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