396 research outputs found

    Can you trust clinical practice guidelines for laparoscopic surgery? A systematic review of clinical practice guidelines for laparoscopic surgery

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    BACKGROUND: Clinical practice guidelines aim to support clinicians in providing clinical care and should be supported by evidence. There is currently no information on whether clinical practice guidelines in laparoscopic surgery are supported by evidence. METHODS: We performed a systematic review and identified clinical practice guidelines of laparoscopic surgery published in PubMed and Embase between March 2016 and February 2019. We performed an independent assessment of the strength of recommendation based on the evidence provided by the guideline authors. We used the 'Appraisal of Guidelines for Research & Evaluation II' (AGREE-II) Tool's 'rigour of development', 'clarity of presentation', and 'editorial independence' domains to assess the quality of the guidelines. We performed a mixed-effects generalised linear regression modelling. RESULTS: We retrieved 63 guidelines containing 1905 guideline statements. The median proportion of 'difference in rating' of strength of recommendation between the guideline authors and independent assessment was 33.3% (quartiles: 18.3%, 55.8%). The 'rigour of development' domain score (odds ratio 0.06; 95% confidence intervals 0.01-0.48 per unit increase in rigour score; P value = 0.0071) and whether the strength of recommendation was 'strong' by independent evaluation (odds ratio 0.09 (95% confidence intervals 0.06-0.13; P value < 0.001) were the only determinants of difference in rating between the guideline authors and independent evaluation. CONCLUSION: A considerable proportion of guideline statements in clinical practice guidelines in laparoscopic surgery are not supported by evidence. Guideline authors systematically overrated the strength of the recommendation (i.e., even when the evidence points to weak recommendation, guideline authors made strong recommendations)

    Hyperthyroidism from autoimmune thyroiditis in a man with type 1 diabetes mellitus: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The presentation, diagnosis, clinical course and treatment of a man with hyperthyroidism secondary to autoimmune thyroiditis in the setting of type 1 diabetes mellitus has not previously been described.</p> <p>Case presentation</p> <p>A 32-year-old European-American man with an eight-year history of type 1 diabetes mellitus presented with an unintentional 22-pound weight loss but an otherwise normal physical examination. Laboratory studies revealed a suppressed thyroid-stimulating hormone concentration and an elevated thyroxine level, which are consistent with hyperthyroidism. His anti-thyroid peroxidase antibodies were positive, and his thyroid-stimulating immunoglobulin test was negative. Uptake of radioactive iodine by scanning was 0.5% at 24 hours. The patient was diagnosed with autoimmune thyroiditis. Six weeks following his initial presentation he became clinically and biochemically hypothyroid and was treated with thyroxine.</p> <p>Conclusion</p> <p>This report demonstrates that autoimmune thyroiditis presenting as hyperthyroidism can occur in a man with type 1 diabetes mellitus. Autoimmune thyroiditis may be an isolated manifestation of autoimmunity or may be part of an autoimmune polyglandular syndrome. Among patients with type 1 diabetes mellitus who present with hyperthyroidism, Graves' disease and other forms of hyperthyroidism need to be excluded as autoimmune thyroiditis can progress quickly to hypothyroidism, requiring thyroid hormone replacement therapy.</p

    Paraffin-enabled graphene transfer

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    The transfer process of as-grown graphene limits its electrical performance and reliability. Here, the authors develop a transfer approach using paraffin as a support layer and obtain wrinkle-reduced and clean large-area graphene retaining high mobility

    Glycosaminoglycan Binding Facilitates Entry of a Bacterial Pathogen into Central Nervous Systems

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    Certain microbes invade brain microvascular endothelial cells (BMECs) to breach the blood-brain barrier (BBB) and establish central nervous system (CNS) infection. Here we use the leading meningitis pathogen group B Streptococcus (GBS) together with insect and mammalian infection models to probe a potential role of glycosaminoglycan (GAG) interactions in the pathogenesis of CNS entry. Site-directed mutagenesis of a GAG-binding domain of the surface GBS alpha C protein impeded GBS penetration of the Drosophila BBB in vivo and diminished GBS adherence to and invasion of human BMECs in vitro. Conversely, genetic impairment of GAG expression in flies or mice reduced GBS dissemination into the brain. These complementary approaches identify a role for bacterial-GAG interactions in the pathogenesis of CNS infection. Our results also highlight how the simpler yet genetically conserved Drosophila GAG pathways can provide a model organism to screen candidate molecules that can interrupt pathogen-GAG interactions for future therapeutic applications

    Mechanical cleaning of graphene using in situ electron microscopy

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    Avoiding and removing surface contamination is a crucial task when handling specimens in any scientific experiment. This is especially true for two-dimensional materials such as graphene, which are extraordinarily affected by contamination due to their large surface area. While many efforts have been made to reduce and remove contamination from such surfaces, the issue is far from resolved. Here we report on an in situ mechanical cleaning method that enables the site-specific removal of contamination from both sides of two dimensional membranes down to atomic-scale cleanliness. Further, mechanisms of re-contamination are discussed, finding surface-diffusion to be the major factor for contamination in electron microscopy. Finally the targeted, electron-beam assisted synthesis of a nanocrystalline graphene layer by supplying a precursor molecule to cleaned areas is demonstrated

    Bioactivity, physical and chemical properties of MTA mixed with propylene glycol

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    AbstractObjective To investigate the physical (setting time, hardness, flowability, microstructure) and chemical (pH change, calcium release, crystallinity) properties and the biological outcomes (cell survival and differentiation) of mineral trioxide aggregate (MTA) mixed using different proportions of propylene glycol (PG) and water.Material and Methods White MTA was mixed with different water/PG ratios (100/0, 80/20 and 50/50). Composition (XRD), microstructure (SEM), setting time (ASTM C266-13), flowability (ANSI/ADA 57-2000), Knoop hardness (100 g/10 s) and chemical characteristics (pH change and Ca2+ release for 7 days) were evaluated. Cell proliferation, osteo/odontoblastic gene expression and mineralization induced by MTA mixed with PG were evaluated. MTA discs (5 mm in diameter, 2 mm thick) were prepared and soaked in culture medium for 7 days. Next, the discs were removed and the medium used to culture dental pulp stem cells (DPSC) for 28 days. Cells survival was evaluated using MTS assay (24, 72 and 120 h) and differentiation with RT-PCR (ALP, OCN, Runx2, DSPP and MEPE) and alizarin red staining (7 and 14 days). Data were analysed using one-way ANOVA and Tukey’s post-hoc analysis (a=0.05).Results The addition of PG significantly increased setting time, flowability and Ca2+ release, but it compromised the hardness of the material. SEM showed that 50/50 group resulted porous material after setting due to the incomplete setting reaction, as shown by XRD analysis. The addition of PG (80/20 and 50/50) was not capable to improve cell proliferation or to enhance gene expression, and mineralized deposition of DPSC after 7 and 14 days as compared to the 100/0.Conclusion Except for flowability, the addition of PG did not promote further improvements on the chemical and physical properties evaluated, and it was not capable of enhancing the bioactivity of the MTA

    Graft-vs-tumor effect in patients with advanced nasopharyngeal cancer treated with nonmyeloablative allogeneic PBSC transplantation

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    While nonmyeloablative peripheral blood stem cell transplantation (NST) has shown efficacy against several solid tumors, it is untested in nasopharyngeal cancer (NPC). In a phase II clinical trial, 21 patients with pretreated metastatic NPC underwent NST with sibling PBSC allografts, using CY conditioning, thymic irradiation and in vivo T-cell depletion with thymoglobulin. Stable lymphohematopoietic chimerism was achieved in most patients and prophylactic CYA was tapered at a median of day +30. Seven patients (33%) showed partial response and three (14%) achieved stable disease. Four patients were alive at 2 years and three showed prolonged disease control of 344, 525 and 550 days. With a median follow-up of 209 (4–1147) days, the median PFS was 100 days (95% confidence interval (CI), 66–128 days), and median OS was 209 days (95% CI, 128–236 days). Patients with chronic GVHD had better survival—median OS 426 days (95% CI, 194–NE days) vs 143 days (95% CI, 114–226 days) (P=0.010). Thus, NST may induce meaningful clinical responses in patients with advanced NPC
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