505 research outputs found

    Production of callus from protoplasts of cultured grape pericarp

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    Protoplasts were isolated from callus cultures of grape vine pericarp after an overnight incubation at 26 °c in 2% Cellulase Onozuka SS plus 1 % Macerozyme dissolved in a mixture of 0.14 molal KCl and 0.10 molal CaCl2 at pH 5.5. When cultured in a liquid medium with either 0.24 M sorbitol or 0.23 M sucrose as osmotic stabilizer, new cell walls were regenerated within the first few days. Cell division commenced by the sixth day of culture, and approximately 0.5% of the population continued dividing. Eventual transfer of the culture to the surface of medium solidified with agar resulted in callus formation.Kallusbildung aus Protoplasten von kultiviertem TraubenperikarpEine Nährlösung wird beschrieben, in der Protoplasten, die aus Kalluskulturen von Traubenperikarp isoliert worden waren, neue Zellwände bildeten und Zellteilungen eingingen. Spätere Übertragung auf einen festen Nährboden ergab aktives Kalluswachstum

    In vitro propagation of grapevine (Vitis vinifera L.) from fragmented shoot apices

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    A method is described for the in vitro propagation of grapevine from fragmented shoot apices, which has the potential to produce approximately 8000 plantlets from a single apex within 4 months. Apical cell clumps were grown in a liquid culture medium with cytokinin but in the absence of auxin. Transfer of the differentiated cell clumps to the same medium gelled with agar resulted in shoot masses which could be repeatedly subcultured. Excised shoots rooted readily on a hormone-free basal medium, and were successfully transferred to glasshouse conditions. This method has potential value in commercial clonal grapevine propagation.In-vitro-Vermehrung der Rebe (Vitis vinifera L.) aus zerstĂĽckelten TriebspitzenEine Methode fĂĽr die in-vitro-Vermehrung der Rebe aus zerstĂĽckelten Triebspitzen wird beschrieben. Zellklumpen der Triebspitze wurden auf einem flĂĽssigen Medium, das Cytokinin, aber kein Auxin enthielt, kultiviert. Nach Ăśbertragung der differenzierten Zellklumpen auf ein mit Agar verfestigtes, aber sonst gleich zusammengesetztes Medium entstanden BĂĽschel von Trieben, die zerteilt und weiter vermehrt werden konnten. Explantierte Einzeltriebe bewurzelten sich auf einem hormonfreien Grundmedium rasch

    Ploidy stability in grapevines following long term storage in vitro

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    A modified method to prepare root tip squashes was used for the routine examination of chromosomes of grapevines developed from in vitro shoot cultures. The results established that adventitious buds obtained by culture of fragmented shoot apices were diploid, and that storage at 9.5 °C of multiple shoot cultures of eight Vitis genotypes for periods up to 12 months did not affect the ploidy level of plants regenerated from them

    Partial characterization of Agrobacterium vitis strains

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    Seventeen strains of Agrobacterium vitis (formerly classified A. tumefaciens biovar 3) were characterized using part of the T-DNA and virA regions of the Ti plasmid as probes. All strains except one were of the wide host range (WHR) strains and were classified into two groups depending on their ability to utilize octopine or nopaline. These WHR type oncogenic strains had homology with the limited host range type (LHR) virA gen of A. vitis but not with the WHR virA gene of A. tumefaciens. The frequency of T-DNA excision in some Agrobacterium strains was estimated with the plasmid pTMA which mimics T-DNA excision from Ti plasmid DNA. In an A. vitis strain isolated from grapevine, T-DNA excision occurred after co-cultivation with grapevine tissues, but not with acetosyringone. In contrast, in A. tumefaciens, T-DNA excision occurred after co-cultivation with acetosyringone, but not with grapevine tissue

    Effect of Root Temperature on Cytokinin Activity in Root Exudate of Vitis vinifera

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    An integrated analysis and comparison of serum, saliva and sebum for COVID-19 metabolomics.

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    The majority of metabolomics studies to date have utilised blood serum or plasma, biofluids that do not necessarily address the full range of patient pathologies. Here, correlations between serum metabolites, salivary metabolites and sebum lipids are studied for the first time. 83 COVID-19 positive and negative hospitalised participants provided blood serum alongside saliva and sebum samples for analysis by liquid chromatography mass spectrometry. Widespread alterations to serum-sebum lipid relationships were observed in COVID-19 positive participants versus negative controls. There was also a marked correlation between sebum lipids and the immunostimulatory hormone dehydroepiandrosterone sulphate in the COVID-19 positive cohort. The biofluids analysed herein were also compared in terms of their ability to differentiate COVID-19 positive participants from controls; serum performed best by multivariate analysis (sensitivity and specificity of 0.97), with the dominant changes in triglyceride and bile acid levels, concordant with other studies identifying dyslipidemia as a hallmark of COVID-19 infection. Sebum performed well (sensitivity 0.92; specificity 0.84), with saliva performing worst (sensitivity 0.78; specificity 0.83). These findings show that alterations to skin lipid profiles coincide with dyslipidaemia in serum. The work also signposts the potential for integrated biofluid analyses to provide insight into the whole-body atlas of pathophysiological conditions

    Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

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    “The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

    Posthumous Medical Data Donation: The Case for a Legal Framework

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    This article explores the options for establishing a legal framework for posthumous medical data donation (PMDD). This concept has not been discussed in legal scholarship to date at all. The paper is, therefore, a first legal study of PMDD, aiming to address the gap and shed light on the most significant legal issues that could affect this concept. The paper starts by looking at the protection of the deceased’s health records and medical data, finding that this protection in law is more extensive than the general protection of the deceased’s personal data, or the protection of post-mortem privacy as a concept. The paper then investigates key issues around ownership and succession of personal data, including medical and health-related data, and how these could affect PMDD and its legal framework. The author then goes on to explore some parallels with organ donation to determine whether there are some lessons to be learned from this comparable regulatory framework. The paper concludes with the discussion around the need for a Code for posthumous medical data donation developed by the Digital Ethics Lab at the Oxford Internet Institute, and a more formal regime that would enable and facilitate this practice. Here, the author proposes key law reforms in the area of data protection and governance related to PMDD. These reforms would include amendments to the general data protection ideally, to ensure harmonisation and consistency across the EU, as well as between the general and sector-specific data protection laws and policies. These changes would contribute to legal and regulatory clarity and would help implement this important and valuable practice, which aims to facilitate research and advances in medical treatments and care
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