958 research outputs found

    Tissue distribution and biochemical properties of an interspecific tumour-associated gamma foetal antigen.

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    A late-gestation neonatal antigen (gamma foetal antigen; gamma-FA) immunologically and biochemically unrelated to murine alpha-foetoprotein, was identified in several spontaneous and carcinogen-induced sarcomas and hepatic carcinomas of the mouse and rat. An approximate mol. wt of 35,000 for gamma-FA from both foetus and tumour was obtained by molecular-sieve chromatography and sucrose-gradient centrifugation. Radial immunodiffusion analyses of organ extracts indicated that gamma-FA could be found in several neonatal tissues, the highest concentration occurring in the spleen. In the 2-month-old mouse, only splenic tissue contained gamma-FA and at much lower levels than in the organ of the newborn mouse

    The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)

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    We report a chip-scale lensless wide-field-of-view microscopy imaging technique, subpixel perspective sweeping microscopy, which can render microscopy images of growing or confluent cell cultures autonomously. We demonstrate that this technology can be used to build smart Petri dish platforms, termed ePetri, for cell culture experiments. This technique leverages the recent broad and cheap availability of high performance image sensor chips to provide a low-cost and automated microscopy solution. Unlike the two major classes of lensless microscopy methods, optofluidic microscopy and digital in-line holography microscopy, this new approach is fully capable of working with cell cultures or any samples in which cells may be contiguously connected. With our prototype, we demonstrate the ability to image samples of area 6 mm × 4 mm at 660-nm resolution. As a further demonstration, we showed that the method can be applied to image color stained cell culture sample and to image and track cell culture growth directly within an incubator. Finally, we showed that this method can track embryonic stem cell differentiations over the entire sensor surface. Smart Petri dish based on this technology can significantly streamline and improve cell culture experiments by cutting down on human labor and contamination risks

    Functionalization of wool with L-cysteine : process characterization and assessment of antimicrobial activity and cytotoxicity

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    This investigation reports a new biotechnological process that uses L-cysteine (L-Cys) which provides a permanent, nontoxic and effective antimicrobial effect over wool-based materials. This process is simple and carried out via idespread exhausting methods. Typically, wool fabrics are incubated with L-Cys for 50 min at 60°C in a pH 4.8 acetate buffer solution 25 mM, under mild agitation to give a good absorption rate. The minimal inhibitory concentration (MIC) of L-Cys was evaluated by the NCCLS M07-A6 standard method, and the results showed a good antibacterial activity against S. aureus and K. pneumoniae within the range of 6.0 × 10−3 − 4.8 × 10−2 g/mL [MIC 0.6% (w/v)] and 6.0 × 10−3 − 4.8 × 10−2 g/mL [MIC 0.6% (w/v)], respectively. In addition, the antimicrobial activity of the functionalized wool was assessed by the international standard JIS 1902-2002 showing a good inhibition of bacterial growth for an L-Cys concentration of 1% over the weight of fabric, both against Staphylococcus aureus and Klebsiella pneumoniae. Moreover, the biocidal mechanism was found to be related with the increase of sulfhydryl's groups onto wool fibers, which were quantified by the Ellman's reagent (5,5′-Dithio-bis(2-nitrobenzoic acid) method. The new process is easy to perform, non toxic, preserve wool quality and is a novel biomimetic approach that uses antimicrobial amino acids and may open new avenues for the design of biomedical textiles with a broad range of applications in healthcare.Contract grant sponsor: FCT; contract grant number: PTDC/EBB-BIO/113671/2009.Contract grant sponsor: R and D Unit of Textile and Paper Materials, Faculty of Engineering, University of Beira Interior

    Enhancing in vitro biocompatibility and corrosion protection of organic-inorganic hybrid sol-gel films with nanocrystalline hydroxyapatite

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    Application of novel organic-inorganic hybrid sol-gel coatings containing dispersed hydroxyapatite (HAp) particles improves the biocompatibility, normal human osteoblast (NHOst) response in terms of osteoblast viability and adhesion of a Ti6Al4V alloy routinely used in medical implants. The incorporation of HAp particles additionally results in more effective barrier proprieties and improved corrosion protection of the Ti6Al4V alloy through higher degree of cross-linking in the organopolysiloxane matrix and enhanced film thickness

    Isolation of a New Natural Product and Cytotoxic and Antimicrobial Activities of Extracts from Fungi of Indonesian Marine Habitats

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    In the search for bioactive compounds, 11 fungal strains were isolated from Indonesian marine habitats. Ethyl acetate extracts of their culture broth were tested for cytotoxic activity against a urinary bladder carcinoma cell line and for antifungal and antibacterial activities against fish and human pathogenic bacteria as well as against plant and human pathogenic fungi. The crude extract of a sterile algicolous fungus (KT31), isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex P.C. Silva exhibited potent cytotoxic activity with an IC50 value of 1.5 μg/mL. Another fungal strain (KT29) displayed fungicidal properties against the plant pathogenic fungus Cladosporium cucumerinum Ell. et Arth. at 50 μg/spot. 2-Carboxy-8-methoxy-naphthalene-1-ol (1) could be isolated as a new natural product
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