170,094 research outputs found
Modification of Loop 1 Affects the Nucleotide Binding Properties of Myo1c, the Adaptation Motor in the Inner Ear
No full textMyo1c is one of eight members of the mammalian myosin I family of actin-associated molecular motors. In stereocilia of the hair cells in the inner ear, Myo1c presumably serves as the adaptation motor, which regulates the opening and closing of transduction channels. Although there is conservation of sequence and structure among all myosins in the N-terminal motor domain, which contains the nucleotide- and actin-binding sites, some differences include the length and composition of surface loops, including loop 1, which lies near the nucleotide-binding domain. To investigate the role of loop 1, we expressed in insect cells mutants of a truncated form of Myo1c, Myo1c1IQ, as well as chimeras of Myo1c1IQ with the analogous loop from other myosins. We found that replacement of the charged residues in loop 1 with alanines or the whole loop with a series of alanines did not alter the ATPase activity, transient kinetics properties, or Ca2+ sensitivity of Myo1c1IQ. Substitution of loop 1 with that of the corresponding region from tonic smooth muscle myosin II (Myo1c1IQ-tonic) or replacement with a single glycine (Myo1c1IQ-G) accelerated the release of ADP from A.M 2?3-fold in Ca2+, whereas substitution with loop 1 from phasic muscle myosin II (Myo1c1IQ-phasic) accelerated the release of ADP 35-fold. Motility assays with chimeras containing a single ?-helix, or SAH, domain showed that Myo1cSAH-tonic translocated actin in vitro twice as fast as Myo1cSAH-WT and 3-fold faster than Myo1cSAH-G. The studies show that changes induced in Myo1c via modification of loop 1 showed no resemblance to the behavior of the loop donor myosins or to the changes previously observed with similar Myo1b chimeras
Gellan-adipic acid blends crosslinked by means of a dehydrothermal treatment
No full textBlends of gellan gum (GE) and adipic acid (ADA), at various ratios, were manufactured in the form of films by casting from aqueous solutions and crosslinked by a dehydrothermal treatment (DHT). The materials, before and after DHT, were characterized by both physicochemical tests and cellular adhesion and growth on the film surfaces. The total reflection and spotlight Fourier transform infrared (FTIR) spectroscopy and optical and scanning electron microscopy showed the presence of both GE-rich and ADA-rich regions and the formation of ester groups after DHT. Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis (DMA) showed that the crosslinking by DHT made the materials more thermally stable. The swelling in water, which diminished in the films subjected to DHT, confirmed that the crosslinking enhanced the whole stability of the material. DMA also showed that the behavior of the GE–ADA blends was quite similar to that of some living tissues, such as the skin. The cell cultures indicated that the materials, especially that with a 6 : 10 ADA-to-GE ratio, were very able to promote cellular adhesion and proliferation. In conclusion, the GE–ADA crosslinked blends appeared very suitable for a use as biomaterials; in particular, the cell cultures indicated that they might be useful as scaffolds for tissue reconstruction
Diagnosis and Management of Autoimmune Hemolytic Anemia in Patients with Liver and Bowel Disorders
No full textAnemia is a common feature of liver and bowel diseases. Although the main causes of anemia in these conditions are represented by gastrointestinal bleeding and iron deficiency, autoimmune hemolytic anemia should be considered in the differential diagnosis. Due to the epidemiological association, autoimmune hemolytic anemia should particularly be suspected in patients affected by inflammatory and autoimmune diseases, such as autoimmune or acute viral hepatitis, primary biliary cholangitis, and inflammatory bowel disease. In the presence of biochemical indices of hemolysis, the direct antiglobulin test can detect the presence of warm or cold reacting antibodies, allowing for a prompt treatment. Drug-induced, immune-mediated hemolytic anemia should be ruled out. On the other hand, the choice of treatment should consider possible adverse events related to the underlying conditions. Given the adverse impact of anemia on clinical outcomes, maintaining a high clinical suspicion to reach a prompt diagnosis is the key to establishing an adequate treatment
Il commento di Benvenuto da Imola alla Pharsalia di Lucano: nuove testimonianze e una proposta per gli autografi di Coluccio Salutati
No full textDopo una panoramica sulla fortuna della «Pharsalia» di Lucano e sulle tappe più significative della sua storia esegetica, il saggio descrive la tradizione manoscritta del commento di Benvenuto da Imola al poema lucaneo, di cui si rendono note e si analizzano diverse nuove testimonianze manoscritte, una delle quali attribuibile alla mano di Coluccio Salutati
Determinants of outcomes of transmural EUS-guided gallbladder drainage: systematic review with proportion meta-analysis and meta-regression
No full textBackground and aims: Transmural EUS-guided gallbladder drainage (EUS-GBD) has been increasingly used in the treatment of gallbladder diseases. Aims of the study were to provide a comprehensive meta-analysis and meta-regression of features and outcomes of this procedure. Methods: MEDLINE, Scopus, Web of science, and Cochrane databases were searched for literature pertinent to transmural EUS-GBD up to May 2021. Random-effect meta-analysis of proportions and meta-regression of potential modifiers of outcome measures considered were applied. Outcome measures were technical success rate, overall clinical success, and procedure-related adverse events (AEs). Results: Twenty-seven articles were identified including 1004 patients enrolled between February 2009 and February 2020. Acute cholecystitis was present in 98.7% of cases. Pooled technical success was 98.0% (95% CI 96.3, 99.3; heterogeneity: 23.6%), the overall clinical success was 95.4% (95% CI 92.8, 97.5; heterogeneity: 35.3%), and procedure-related AEs occurred in 14.8% (95% CI 8.8, 21.8; heterogeneity: 82.4%), being stent malfunction/dislodgement the most frequent (3.5%). Procedural-related mortality was 1‰. Meta-regression showed that center experience proxied to > 10 cases/year increased the technical success rate (odds ratio [OR]: 2.84; 95% CI 1.06, 7.59) and the overall clinical success (OR: 3.52; 95% CI 1.33, 9.33). The use of anti-migrating devices also increased the overall clinical success (OR: 2.16; 95% CI 1.07, 4.36) while reducing procedure-related AEs (OR: 0.36; 95% CI 0.14, 0.98). Conclusion: Physicians’ experience and anti-migrating devices are the main determinants of main clinical outcomes after EUS-GBD, suggesting that treatment in expert centers would optimize results
The other side of malnutrition in inflammatory bowel disease (Ibd): Non-alcoholic fatty liver disease
No full textSteatohepatitis and hepatobiliary manifestations constitute some of the most common extraintestinal manifestations of Inflammatory Bowel Disease (IBD). On the other hand, non-alcoholic fatty liver disease (NAFLD) affects around 25% of the world’s population and is attracting ever more attention in liver transplant programs. To outline the specific pathways linking these two conditions is a pressing task for 21st-century researchers. We are accustomed to expecting the occurrence of fatty liver disease in obese people, but current evidence suggests that there are several different pathways also occurring in underweight patients. Genetic factors, inflammatory signals and microbiota are key players that could help in understanding the entire pathogenesis of NAFLD, with the aim of defining the multiple expressions of malnutrition. In the current review, we summarize the most recent literature regarding the epidemiology, pathogenesis and future directions for the management of NAFLD in patients affected by IBD
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Surface modification of poly(ethylene-co-vinyl alcohol) membranes by molecular imprinting technique for biomedical application
No full textPoly(ethylene-co-vinyl alcohol) Membranes with Specific Adsorption Properties for Potential Clinical Application
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