442 research outputs found

    Validating silicon polytrodes with paired juxtacellular recordings: method and dataset

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    Cross-validating new methods for recording neural activity is necessary to accurately interpret and compare the signals they measure. Here we describe a procedure for precisely aligning two probes for in vivo “paired-recordings” such that the spiking activity of a single neuron is monitored with both a dense extracellular silicon polytrode and a juxtacellular micropipette. Our new method allows for efficient, reliable, and automated guidance of both probes to the same neural structure with micrometer resolution. We also describe a new dataset of paired-recordings, which is available online. We propose that our novel targeting system, and ever expanding cross-validation dataset, will be vital to the development of new algorithms for automatically detecting/sorting single-units, characterizing new electrode materials/designs, and resolving nagging questions regarding the origin and nature of extracellular neural signals

    Tuberculosis screening in patients receiving biological therapy

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    AIM: Biological therapies are a risk factor for tuberculosis (TB). Portuguese recommendations recommend universal baseline screening for TB before starting biologics (2006) and annually thereafter if screened negative (2012 update). The gain with re-screening remains unknown. We aimed to i)identify the risk of latent TB infection at baseline screening among patients candidates to initiate biologics ii)present follow-up results for patients receiving different biological therapies and analyse intolerance or toxicity related to preventive therapy, conversions of immunodiagnostic tests under biological therapy and development of active TB. METHODS: Patients screened for TB at a reference centre before starting biological therapy between 2008-2012 were identified. Medical files were retrospectively reviewed. Demographic data, screening and follow-up results and information on biological therapy were collected. EXCLUSION CRITERIA: unavailable information on initiation of biological therapy. RESULTS: 183 patients were included in the study, with 115 starting biological therapy. The baseline screening was positive in 52(45,2%) patients - 50(96,2%) were proposed for preventive treatment (2 had abnormal liver enzymes). Mild hepatotoxicity occurred in 4(8%) patients without need to interrupt TB prophylaxis. No cases of active TB occurred during follow-up in patients with positive baseline screening. Among the 63(54,8%) patients who screened negative, 2(3,2%) developed active TB (under infliximab and adalimumab) more than one year after initiation of biologics. 26(41,3%) patients were re-screened at the TB centre. 5(19,2%) had tuberculin skin test (TST) conversion and one concomitantly undetermined IGRA. No IGRA conversions were observed. The follow-up period was 4,0 years. TB baseline screening's negative predictive value (NPV) was 96,8% (95%CI: 89,0% to 99.5%). A low rate of re-screening was observed. CONCLUSION: The rate of latent TB at baseline screening was higher than expected. Preventive treatment was well tolerated. No patients with positive baseline screening developed active TB. Efforts should be made to raise awareness concerning the risk of TB exposure, specially considering that the active TB cases were compatible with new infection. The rate of re-screening suggests a low awareness regarding current recommendations Nation-wide studies are necessary to evaluate the efficacy of the re-screening strategy and to clarify what risk groups most benefit from it

    Studies on an alkali-thermostable xylanase from Aspergillus fumigatus MA28

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    An alkalitolerant fungus, Aspergillus fumigatus strain MA28 produced significant amounts of cellulase-free xylanase when grown on a variety of agro-wastes. Wheat bran as the sole carbon source supported higher xylanase production (8,450 U/L) than xylan (7,500 U/L). Soybean meal was observed to be the best nitrogen source for xylanase production (9,000 U/L). Optimum medium pH for xylanase production was 8 (9,800 U/L), though, significant quantities of the enzyme was also produced at pH 7 (8,500 U/L), 9 (8,200 U/L) and 10 (4,600 U/L). The xylanase was purified by ammonium sulphate precipitation and carboxymethyl cellulose chromatography, and was found to have a molecular weight of 14.4 kDa with a Vmax of 980 μmol/min/mg of protein and a Km of approximately 4.9 mg/mL. The optimum temperature and pH for enzyme activity was 50 °C and pH 8, respectively. However, the enzyme also showed substantial residual activity at 60–70 °C (53–75%) and at alkaline pH 8–9 (56–88%)

    Epidemiology, Quality and Reporting Characteristics of Systematic Reviews of Traditional Chinese Medicine Interventions Published in Chinese Journals

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    Systematic reviews (SRs) of TCM have become increasingly popular in China and have been published in large numbers. This review provides the first examination of epidemiological characteristics of these SRs as well as compliance with the PRISMA and AMSTAR guidelines.To examine epidemiological and reporting characteristics as well as methodological quality of SRs of TCM published in Chinese journals.Four Chinese databases were searched (CBM, CSJD, CJFD and Wanfang Database) for SRs of TCM, from inception through Dec 2009. Data were extracted into Excel spreadsheets. The PRISMA and AMSTAR checklists were used to assess reporting characteristics and methodological quality, respectively.A total of 369 SRs were identified, most (97.6%) of which used the terms systematic review or meta-analysis in the title. None of the reviews had been updated. Half (49.8%) were written by clinicians and nearly half (47.7%) were reported in specialty journals. The impact factors of 45.8% of the journals published in were zero. The most commonly treated conditions were diseases of the circulatory and digestive disease. Funding sources were not reported for any reviews. Most (68.8%) reported information about quality assessment, while less than half (43.6%) reported assessing for publication bias. Statistical mistakes appeared in one-third (29.3%) of reviews and most (91.9%) did not report on conflict of interest.While many SRs of TCM interventions have been published in Chinese journals, the quality of these reviews is troubling. As a potential key source of information for clinicians and researchers, not only were many of these reviews incomplete, some contained mistakes or were misleading. Focusing on improving the quality of SRs of TCM, rather than continuing to publish them in great quantity, is urgently needed in order to increase the value of these studies
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