479 research outputs found

    Couching in Nigeria: prevalence, risk factors and visual acuity outcomes.

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    PURPOSE: Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria. METHODS: Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging. RESULTS: Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60). CONCLUSIONS: Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country

    Recurrent Transvaginal Leak of Dialysate as a Complication of Peritoneal Dialysis Catheter Tip Capture by Fallopian Tube after Tubal Occlusion

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    Introduction: Peritoneal dialysis (PD) catheter malfunction may result from obstruction by various intra-peritoneal structures. Such obstruction may rarely be caused by fallopian tubes, in which case it may present as out flow failure and/or per vaginum (PV) leak of dialysate. Case report: A 46 years old female developed early out-flow obstruction while maintaining adequate dialysate inflow soon after PD catheter insertion. The patient also had PV leak of the dialysate that was misinterpreted by the patient as urine incontinence. Fluoroscopic catheterogram confirmed catheter patency and outlined the right fallopian tube. Magnetic Resonance Imaging (MRI) revealed the presence of fluid in vagina with no obvious peritoneo-vaginal fistulous track. Laparoscopy was performed, at which time examination under anesthesia excluded the presence of peritoneo-vaginal fistula. During laparoscopy, the catheter tip was found to be captured by the fimbriae of the right fallopian tube. The catheter tip was released and right tubal occlusion was performed, after which adequate flow was restored. Three month later, the catheter was replaced because of fungal peritonitis. Vaginal leak recurred six weeks after insertion of the new catheter through the same occluded tube. Mini laparotomy and tubal ligation with catheter removal were done and the patient was maintained on hemodialysis until she received a kidney transplant four months later. Conclusion: Vaginal leak of dialysate can occur as an early complication of PD secondary to fallopian tube capture of PD catheter tip. It is important to distinguish between tubal capture of the catheter tip which can be treated laparoscopically and peritoneo-vaginal fistula which often requires laparotomy for fistulous tract debridement and repair. Key words: Peritoneal Dialysis, Dialysate, Transvaginal leak, Fallopian tub

    Low Concentrations of Methamphetamine Can Protect Dopaminergic Cells against a Larger Oxidative Stress Injury: Mechanistic Study

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    Mild stress can protect against a larger insult, a phenomenon termed preconditioning or tolerance. To determine if a low intensity stressor could also protect cells against intense oxidative stress in a model of dopamine deficiency associated with Parkinson disease, we used methamphetamine to provide a mild, preconditioning stress, 6-hydroxydopamine (6-OHDA) as a source of potentially toxic oxidative stress, and MN9D cells as a model of dopamine neurons. We observed that prior exposure to subtoxic concentrations of methamphetamine protected these cells against 6-OHDA toxicity, whereas higher concentrations of methamphetamine exacerbated it. The protection by methamphetamine was accompanied by decreased uptake of both [3H] dopamine and 6-OHDA into the cells, which may have accounted for some of the apparent protection. However, a number of other effects of methamphetamine exposure suggest that the drug also affected basic cellular survival mechanisms. First, although methamphetamine preconditioning decreased basal pERK1/2 and pAkt levels, it enhanced the 6-OHDA-induced increase in these phosphokinases. Second, the apparent increase in pERK1/2 activity was accompanied by increased pMEK1/2 levels and decreased activity of protein phosphatase 2. Third, methamphetamine upregulated the pro-survival protein Bcl-2. Our results suggest that exposure to low concentrations of methamphetamine cause a number of changes in dopamine cells, some of which result in a decrease in their vulnerability to subsequent oxidative stress. These observations may provide insights into the development of new therapies for prevention or treatment of PD

    Effects of pretreatments of Napier Grass with deionized water, sulfuric acid and sodium hydroxide on pyrolysis oil characteristics

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    The depletion of fossil fuel reserves has led to increasing interest in liquid bio-fuel from renewable biomass. Biomass is a complex organic material consisting of different degrees of cellulose, hemicellulose, lignin, extractives and minerals. Some of the mineral elements tend to retard conversions, yield and selectivity during pyrolysis processing. This study is focused on the extraction of mineral retardants from Napier grass using deionized water, dilute sodium hydroxide and sulfuric acid and subsequent pyrolysis in a fixed bed reactor. The raw biomass was characterized before and after each pretreatment following standard procedure. Pyrolysis study was conducted in a fixed bed reactor at 600 o�C, 30 �C/min and 30 mL/min N2 flow. Pyrolysis oil (bio-oil) collected was analyzed using standard analytic techniques. The bio-oil yield and characteristics from each pretreated sample were compared with oil from the non-pretreated sample. Bio-oil yield from the raw sample was 32.06 wt% compared to 38.71, 33.28 and 29.27 wt% oil yield recorded from the sample pretreated with sulfuric acid, deionized water and sodium hydroxide respectively. GC–MS analysis of the oil samples revealed that the oil from all the pretreated biomass had more value added chemicals and less ketones and aldehydes. Pretreatment with neutral solvent generated valuable leachate, showed significant impact on the ash extraction, pyrolysis oil yield, and its composition and therefore can be regarded as more appropriate for thermochemical conversion of Napier grass

    Inhibition of Src kinase activity attenuates amyloid associated microgliosis in a murine model of Alzheimer’s disease

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    <p>Abstract</p> <p>Background</p> <p>Microglial activation is an important histologic characteristic of the pathology of Alzheimer’s disease (AD). One hypothesis is that amyloid beta (Aβ) peptide serves as a specific stimulus for tyrosine kinase-based microglial activation leading to pro-inflammatory changes that contribute to disease. Therefore, inhibiting Aβ stimulation of microglia may prove to be an important therapeutic strategy for AD.</p> <p>Methods</p> <p>Primary murine microglia cultures and the murine microglia cell line, BV2, were used for stimulation with fibrillar Aβ1-42. The non-receptor tyrosine kinase inhibitor, dasatinib, was used to treat the cells to determine whether Src family kinase activity was required for the Aβ stimulated signaling response and subsequent increase in TNFα secretion using Western blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. A histologic longitudinal analysis was performed using an AD transgenic mouse model, APP/PS1, to determine an age at which microglial protein tyrosine kinase levels increased in order to administer dasatinib via mini osmotic pump diffusion. Effects of dasatinib administration on microglial and astroglial activation, protein phosphotyrosine levels, active Src kinase levels, Aβ plaque deposition, and spatial working memory were assessed via immunohistochemistry, Western blot, and T maze analysis.</p> <p>Results</p> <p>Aβ fibrils stimulated primary murine microglia via a tyrosine kinase pathway involving Src kinase that was attenuated by dasatinib. Dasatinib administration to APP/PS1 mice decreased protein phosphotyrosine, active Src, reactive microglia, and TNFα levels in the hippocampus and temporal cortex. The drug had no effect on GFAP levels, Aβ plaque load, or the related tyrosine kinase, Lyn. These anti-inflammatory changes correlated with improved performance on the T maze test in dasatinib infused animals compared to control animals.</p> <p>Conclusions</p> <p>These data suggest that amyloid dependent microgliosis may be Src kinase dependent <it>in vitro</it> and <it>in vivo.</it> This study defines a role for Src kinase in the microgliosis characteristic of diseased brains and suggests that particular tyrosine kinase inhibition may be a valid anti-inflammatory approach to disease. Dasatinib is an FDA-approved drug for treating chronic myeloid leukemia cancer with a reported ability to cross the blood-brain barrier. Therefore, this suggests a novel use for this drug as well as similar acting molecules.</p

    Dijet Resonance Search with Weak Supervision Using root S=13 TeV pp Collisions in the ATLAS Detector

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    This Letter describes a search for narrowly resonant new physics using a machine-learning anomaly detection procedure that does not rely on signal simulations for developing the analysis selection. Weakly supervised learning is used to train classifiers directly on data to enhance potential signals. The targeted topology is dijet events and the features used for machine learning are the masses of the two jets. The resulting analysis is essentially a three-dimensional search A → BC, for mA ∼ OðTeVÞ, mB; mC ∼ Oð100 GeVÞ and B, C are reconstructed as large-radius jets, without paying a penalty associated with a large trials factor in the scan of the masses of the two jets. The full run 2 ffiffi s p ¼ 13 TeV pp collision dataset of 139 fb−1 recorded by the ATLAS detector at the Large Hadron Collider is used for the search. There is no significant evidence of a localized excess in the dijet invariant mass spectrum between 1.8 and 8.2 TeV. Cross-section limits for narrow-width A, B, and C particles vary with mA, mB, and mC. For example, when mA ¼ 3 TeV and mB ≳ 200 GeV, a production cross section between 1 and 5 fb is excluded at 95% confidence level, depending on mC. For certain masses, these limits are up to 10 times more sensitive than those obtained by the inclusive dijet search. These results are complementary to the dedicated searches for the case that B and C are standard model boson
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