856 research outputs found

    The development of Wasabia Japonica (MIQ.) Matsumura in vitro

    Full text link
    University of Technology Sydney. Faculty of Science.The aim of this project was to investigate the feasibility of the development of in vitro methods for assisting in the plant breeding of the important culinary and medicinal plant, Wasabia japonica Matsumura, through rapid plantlet production and improved plant quality, by the application of micro-propagation and induced mutation techniques. The synthesis and accumulation of a key valuable chemical component was also examined, through callus culture, tissue culture, and induced mutation. In vitro propagation systems by means of gelled and liquid culture were developed for W. japonica. In vivo dormant buds were used as a primary source of explants, following disinfection in alcohol, NaOCl and detergent. Explants were successfully initiated in culture followed by a rapid shoot multiplication on gelled basal media containing nutrient salts of Murashige and Skoog (MS), vitamins, sucrose and growth regulators. Amongst various cytokinins used (BA, TDZ, kinetin and zeatin) BA proved to be the most effective, with the best concentration at 5 µM. Combinations among growth regulators enhanced shoot proliferation. In order to establish a simple and efficient in vitro propagation protocol, ½MS liquid culture medium with 5°μM BA was used for effective shoot multiplication of W. japonica with reduced labour and cost. The best rooting occurred in shoots cultured on gelled ½MS basal medium supplemented with 10°μM IBA. Over ninety per cent of plantlets were successfully acclimatised to in vivo conditions, exhibiting normal development. The effects of in vitro mutation induction by physical and chemical mutagens on wasabi shoot tips were also investigated. Gamma rays and X-rays as physical mutagens in the range of 10 to 40 Gy, reduced the allyl isothiocyanate content of in vitro explants, to a greater extent as doses increased. X-ionising irradiation had a more detrimental influence on survival and growth of wasabi tissues than gamma-ionising irradiation. Colchicine and oryzalin as chemical mutagens, however, did not reduce the content of this compound. Oryzalin appeared to be more phytotoxic than colchicine, with a concentration of 15 μM affecting explant growth. Conversely, a low concentration of colchicine at 25 μM appeared to be favourable for the growth and development in vitro. Leaf morphology appeared to be altered in several greenhouse-grown plants treated with chemical mutagens, exhibiting typical characteristics of polyploids. Further studies of morphological effects and assessments of the alteration of allyl isothiocyanate need to be undertaken on in vivo-grown plants. The yield of allyl isothiocyanate was investigated in calluses, in vitro mutated- and non-mutated explants, and in vivo plants. Light conditions and leaf tissues proved to be more effective than dark conditions and petiole tissues, respectively, for the accumulation of this component in callus cultures. Shoot bases accumulated higher yield than leaves and petioles in the in vitro explants over three months in culture. Similarly, roots and rhizomes produced higher yields than leaves and petioles of in vivo plants over a period of 12 months. Leaves accumulated greater amounts of allyl isothiocyanate than petioles in vitro, but lower amounts than petioles in vivo. Thus it appears that he harvest of allyl isothiocyanate in plant leaves and petioles in vivo could be most effectively commenced after growth for nine months. These results lay a scientific foundation on which a more elaborated and effective system of in vitro propagation and improvement for W. japonica can be achieved. Further studies on the analysis of chemical components need to be conducted for the pharmacautical uses of this plant

    Fermion Masses in Emergent Electroweak Symmetry Breaking

    Full text link
    We consider the generation of fermion masses in an emergent model of electroweak symmetry breaking with composite W,ZW,Z gauge bosons. A universal bulk fermion profile in a warped extra dimension is used for all fermion flavors. Electroweak symmetry is broken at the UV (or Planck) scale where boundary mass terms are added to generate the fermion flavor structure. This leads to flavor-dependent nonuniversality in the gauge couplings. The effects are suppressed for the light fermion generations but are enhanced for the top quark where the ZttˉZt{\bar t} and WtbˉWt{\bar b} couplings can deviate at the 102010-20% level in the minimal setup. By the AdS/CFT correspondence our model implies that electroweak symmetry is not a fundamental gauge symmetry. Instead the Standard Model with massive fermions and W,ZW,Z gauge bosons is an effective chiral Lagrangian for some underlying confining strong dynamics at the TeV scale, where mass is generated without a Higgs mechanism.Comment: modified discussion in Sec 3.1, version published in JHE

    The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.

    Get PDF
    Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex

    Feasibility of Image-Guided Radiotherapy for Elderly Patients with Locally Advanced Rectal Cancer

    Get PDF
    PURPOSE: The study aims to assess the tolerance of elderly patients (70 years or older) with locally advanced rectal cancers to image-guided radiotherapy (IGRT). A retrospective review of 13 elderly patients with locally advanced rectal cancer who underwent preoperative chemoradiation using IGRT was performed. Grade 3-4 acute toxicities, survival, and long-term complications were compared to 17 younger patients (<70 years) with the same disease stage. RESULTS: Grade 3-4 hematologic toxicities occurred in 7.6% and 0% (p = 0.4) and gastrointestinal toxicities, and, in 15.2% and 5% (p = 0.5), of elderly and younger patients, respectively. Surgery was aborted in three patients, two in the elderly group and one in the younger group. One patient in the elderly group died after surgery from cardiac arrhythmia. After a median follow-up of 34 months, five patients had died, two in the elderly and three in the younger group. The 3-year survival was 90.9% and 87.5% (p = 0.7) for the elderly and younger group respectively. Two patients in the younger group developed ischemic colitis and fecal incontinence. There was no statistically significant difference in acute and late toxicities as well as survival between the two groups. CONCLUSIONS AND CLINICAL RELEVANCE: Elderly patients with locally advanced rectal cancers may tolerate preoperative chemoradiation with IGRT as well as younger patients. Further prospective studies should be performed to investigate the potential of IGRT for possible cure in elderly patients with locally advanced rectal cancer

    Measures of satisfaction with care during labour and birth: a comparative review

    Get PDF
    Background Satisfaction is the one of the most frequently reported outcome measures for quality of care. Assessment of satisfaction with maternity services is crucial, and psychometrically sound measures are needed if this is to inform health practices. This paper comparatively reviews current measures of satisfaction with care during labour and birth. Methods A review of the literature was conducted. Studies were located through computerised databases and hand searching references of identified articles and reviews. Inclusion criteria were that the questionnaire was a multi-item scale of satisfaction with care during labour and birth, and some form of psychometric information (either information about questionnaire construction, or reliability, or validity) had to be reported. Results Nine questionnaires of satisfaction with care during labour and birth were identified. Instruments varied in psychometric properties and dimensions. Most described questionnaire construction and tested some form of reliability and validity. Measures were generally not based on the main theoretical models of satisfaction and varied in scope and application to different types of samples (e.g. satisfaction following caesarean section). For an in-depth measure of satisfaction with intrapartum care, the Intrapartal-Specific Quality from the Patient’s Perspective questionnaire (QPP-I) is recommended. Brief measures with good reliability and validity are provided by the Six Simple Questions (SSQ) or Perceptions of Care Adjective Checklist (PCACL-R). Conclusions Despite the interest in measures of satisfaction there are only a small number of validated measures of satisfaction with care during labour and birth. It is important that brief, reliable and valid measures are available for use in general and specific populations in order to assist research and inform practice

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

    Get PDF
    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Competitive and Cooperative Interactions Mediate RNA Transfer from Herpesvirus Saimiri ORF57 to the Mammalian Export Adaptor ALYREF

    Get PDF
    The essential herpesvirus adaptor protein HVS ORF57, which has homologs in all other herpesviruses, promotes viral mRNA export by utilizing the cellular mRNA export machinery. ORF57 protein specifically recognizes viral mRNA transcripts, and binds to proteins of the cellular transcription-export (TREX) complex, in particular ALYREF. This interaction introduces viral mRNA to the NXF1 pathway, subsequently directing it to the nuclear pore for export to the cytoplasm. Here we have used a range of techniques to reveal the sites for direct contact between RNA and ORF57 in the absence and presence of ALYREF. A binding site within ORF57 was characterized which recognizes specific viral mRNA motifs. When ALYREF is present, part of this ORF57 RNA binding site, composed of an a-helix, binds preferentially to ALYREF. This competitively displaces viral RNA from the a-helix, but contact with RNA is still maintained by a flanking region. At the same time, the flexible N-terminal domain of ALYREF comes into contact with the viral RNA, which becomes engaged in an extensive network of synergistic interactions with both ALYREF and ORF57. Transfer of RNA to ALYREF in the ternary complex, and involvement of individual ORF57 residues in RNA recognition, were confirmed by UV cross-linking and mutagenesis. The atomic-resolution structure of the ORF57-ALYREF interface was determined, which noticeably differed from the homologous ICP27-ALYREF structure. Together, the data provides the first site-specific description of how viral mRNA is locked by a herpes viral adaptor protein in complex with cellular ALYREF, giving herpesvirus access to the cellular mRNA export machinery. The NMR strategy used may be more generally applicable to the study of fuzzy protein-protein-RNA complexes which involve flexible polypeptide regions

    Differential expression of centrosomal proteins at different stages of human glioma

    Get PDF
    BACKGROUND: High-grade gliomas have poor prognosis, requiring aggressive treatment. The aim of this study is to explore mitotic and centrosomal dysregulation in gliomas, which may provide novel targets for treatment. METHODS: A case-control study was performed using 34 resected gliomas, which were separated into low- and high-grade groups. Normal human brain tissue was used as a control. Using immunohistochemical analysis, immunofluorescent microscopy, and RT-PCR, detection of centrins 1 and 2, γ-tubulin, hNinein, Aurora A, and Aurora B, expression was performed. Analysis of the GBM8401 glioma cell line was also undertaken to complement the in vivo studies. RESULTS: In high-grade gliomas, the cells had greater than two very brightly staining centrioles within large, atypical nuclei, and moderate-to-strong Aurora A staining. Comparing with normal human brain tissue, most of the mRNAs expression in gliomas for centrosomal structural proteins, including centrin 3, γ-tubulin, and hNinein isoforms 1, 2, 5 and 6, Aurora A and Aurora B were elevated. The significant different expression was observed between high- and low-grade glioma in both γ-tubulin and Aurora A mRNA s. In the high-grade glioma group, 78.6% of the samples had higher than normal expression of γ-tubulin mRNA, which was significantly higher than in the low-grade glioma group (18.2%, p < 0.05). CONCLUSIONS: Markers for mitotic dysregulation, such as supernumerary centrosomes and altered expression of centrosome-related mRNA and proteins were more frequently detected in higher grade gliomas. Therefore, these results are clinically useful for glioma staging as well as the development of novel treatments strategies

    Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders

    Get PDF
    Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively
    corecore