1,720,966 research outputs found
INTRACELLULAR DNA DELIVERY USING POLYMERIC NANOPARTICLES FOR LYSOSOMAL STORAGE DISORDERS GENE THERAPY
No full textINTRODUCTION: Gene therapy can be currently performed by viral or non-viral vectors. Although viral ones have already come to a clinical translation, concerns remain about both safety and the industrial applicability of this system.
We therefore started the study of a transposon-based gene transfer system. We used nanoparticles (NPs) as vector to carry the transposon within the blood stream, then in cells. These had to be able to hold large plasmids, such as transposon. The NPs must then be able to reach the tissue most affected by the genetic disorder. Coating the NPs with specific peptides, they acquire the ability to accumulate in the target tissue, in our case the Central Nervous System (CNS) penetrating the blood-brain barrier (BBB). We started to develop a non-viral gene therapy approach in order to treat a neurological disease, globoid cell leukodystrophy in (GLD), an inherited, rapidly fatal disorder affecting myelin.
METHODS: We tested the ability of a transposon-based system called Sleeping Beauty (SB), to convey the luciferase marker gene in the control cells.
We then verified the ability of NPS of chitosan to contain large plasmids. We then verified the quality (size, shape) of the NPS obtained and their ability to integrate the gene of interest (GALC) within the cellular genome.
Lastly, we verified the ability of a heptameric synthetic glycopeptide, of opioid origin, g7, to convey inside the CNS NPs of Poly Lactic-Co-Glycolic Acid (PLGA). We injected PLGA NPs coated with g7 in tail vein’s Balb/c mice and followed through fluorescence spectroscopy their distribution.
RESULTS: We verified the high SB transduction efficiency on control cells by their expression of luciferase marker gene. We then assessed the copies number of the integrated gene.
We demonstrated the high transduction efficiency of the transgene within the genome of fibroblasts grown from biopsies of patients with GLD.
We assessed the quality and features of chitosan-SB NPs.
We could observe that g7 coated PLGA NPs accumulate in the CNS 10 minutes after infusion, with accumulation even and up to 2 hours.
DISCUSSION: SB demonstrated high efficiency in stable transduction of control cells. So we thought to encapsulate SB in chitosan NPs. These have proven to be highly efficient in stably transducing deficient fibroblasts. We can confirm that g7 is today the best way to address the NPs to the CNS.
CONCLUSIONS: Future studies will test the ability of g7 to coat the NPs of chitosan, verify its efficiency in conveying the chitosan NPs to the CNS as well as they did for PLGA NPs. Finally, by cloning into SB the gene whose mutation causes GLD, can be assessed the therapeutic efficacy of the system in the mouse model of the disease
PMM2-CDG: Phenotype and genotype in four affected family members
No full textAbstract
Congenital disorders of glycosylation (CDG) are genetic defects in protein and lipid glycosylation. PMM2-CDG is the most prevalent protein N-glycosylation disorder with more than 700 reported patients. Here we report on a large Italian family with four affected members and three mutations. Two young sisters are compound heterozygous for mutations p.Leu32Arg and p.Arg141His, while two paternal great-aunts are compound heterozygosity for p.Leu32Arg and p.Thr237Met. The latter association has not been reported before. The most severely affected member had in addition an ALG6 mutation known to exacerbate the phenotype of patients with PMM2-CDG.
Abbreviations
CDG, Congenital disorders of glycosylation; PMM2, phosphomannomutase 2; ALG6, alpha-1,3-glucosyltransferase; CDT, carbohydrate-deficient transferri
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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