325 research outputs found

    Spectral analysis of Gene co-expression network of Zebrafish

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    We analyze the gene expression data of Zebrafish under the combined framework of complex networks and random matrix theory. The nearest neighbor spacing distribution of the corresponding matrix spectra follows random matrix predictions of Gaussian orthogonal statistics. Based on the eigenvector analysis we can divide the spectra into two parts, first part for which the eigenvector localization properties match with the random matrix theory predictions, and the second part for which they show deviation from the theory and hence are useful to understand the system dependent properties. Spectra with the localized eigenvectors can be characterized into three groups based on the eigenvalues. We explore the position of localized nodes from these different categories. Using an overlap measure, we find that the top contributing nodes in the different groups carry distinguished structural features. Furthermore, the top contributing nodes of the different localized eigenvectors corresponding to the lower eigenvalue regime form different densely connected structure well separated from each other. Preliminary biological interpretation of the genes, associated with the top contributing nodes in the localized eigenvectors, suggests that the genes corresponding to same vector share common features.Comment: 6 pages, four figures (accepted in EPL

    Phase I/Phase II study of blinatumomab in pediatric patients with relapsed/refractory acute lymphoblastic leukemia

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    Purpose Blinatumomab is a bispecific T-cell engager antibody construct targeting CD19 on B-cell lymphoblasts. Weevaluated the safety, pharmacokinetics, recommended dosage, and potential for efficacy of blinatumomab in children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Methods This open-label study enrolled children , 18 years old with relapsed/refractory BCP-ALL in a phase I dosage-escalation part and a phase II part, using 6-week treatment cycles. Primary end points were maximum-tolerated dosage (phase I) and complete remission rate within the first two cycles (phase II). Results We treated 49 patients in phase I and 44 patients in phase II. Four patients had dose-limiting toxicities in cycle 1 (phase I). Three experienced grade 4 cytokine-release syndrome (one attributed to grade 5 cardiac failure); one had fatal respiratory failure. The maximum-tolerated dosage was 15 mg/m2d. Blinatumomab pharmacokinetics was linear across dosage levels and consistent among age groups. On the basis of the phase I data, the recommended blinatumomab dosage for children with relapsed/refractory ALL was 5 mg/m2d for the first 7 days, followed by 15 mg/m2d thereafter. Among the 70 patients who received the recommended dosage, 27 (39%; 95% CI, 27% to 51%) achieved complete remission within the first two cycles, 14 (52%) of whom achieved complete minimal residual disease response. The most frequent grade $ 3 adverse events were anemia (36%), thrombocytopenia (21%), and hypokalemia (17%). Three patients (4%) and one patient (1%) had cytokine-release syndrome of grade 3 and 4, respectively. Two patients (3%) interrupted treatment after grade 2 seizures. Conclusion This trial, which to the best of our knowledge was the first such trial in pediatrics, demonstrated antileukemic activity of single-agent blinatumomab with complete minimal residual disease response in children with relapsed/refractory BCP-ALL. Blinatumomab may represent an important new treatment option in this setting, requiring further investigation in curative indications

    The dual-acting chemotherapeutic agent Alchemix induces cell death independently of ATM and p53

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    YesTopoisomerase inhibitors are in common use as chemotherapeutic agents although they can display reduced efficacy in chemotherapy-resistant tumours, which have inactivated DNA damage response (DDR) genes, such as ATM and TP53. Here, we characterise the cellular response to the dual-acting agent, Alchemix (ALX), which is a modified anthraquinone that functions as a topoisomerase inhibitor as well as an alkylating agent. We show that ALX induces a robust DDR at nano-molar concentrations and this is mediated primarily through ATR- and DNA-PK- but not ATM-dependent pathways, despite DNA double strand breaks being generated after prolonged exposure to the drug. Interestingly, exposure of epithelial tumour cell lines to ALX in vitro resulted in potent activation of the G2/M checkpoint, which after a prolonged arrest, was bypassed allowing cells to progress into mitosis where they ultimately died by mitotic catastrophe. We also observed effective killing of lymphoid tumour cell lines in vitro following exposure to ALX, although, in contrast, this tended to occur via activation of a p53-independent apoptotic pathway. Lastly, we validate the effectiveness of ALX as a chemotherapeutic agent in vivo by demonstrating its ability to cause a significant reduction in tumour cell growth, irrespective of TP53 status, using a mouse leukaemia xenograft model. Taken together, these data demonstrate that ALX, through its dual action as an alkylating agent and topoisomerase inhibitor, represents a novel anti-cancer agent that could be potentially used clinically to treat refractory or relapsed tumours, particularly those harbouring mutations in DDR genes

    Do teashirt family genes specify trunk identity? Insights from the single tiptop/teashirt homolog of Tribolium castaneum

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    The Drosophila teashirt gene acts in concert with the homeotic selector (Hox) genes to specify trunk (thorax and abdomen) identity. There has been speculation that this trunk-specifying function might be very ancient, dating back to the common ancestor of insects and vertebrates. However, other evidence suggests that the role of teashirt in trunk identity is not well conserved even within the Insecta. To address this issue, we have analyzed the function of Tc-tiotsh, the lone teashirt family member in the red flour beetle, Tribolium castaneum. Although Tc-tiotsh is important for aspects of both embryonic and imaginal development including some trunk features, we find no evidence that it acts as a trunk identity gene. We discuss this finding in the context of recent insights into the evolution and function of the Drosophila teashirt family genes

    Targeting survivin and p53 in pediatric acute lymphoblastic leukemia

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    Despite advances in treatment and outcomes for patients with pediatric acute lymphoblastic leukemia (ALL), there continue to be subsets of patients who are refractory to standard chemotherapy and hematopoietic stem cell transplant. Therefore, novel gene targets for therapy are needed to further advance treatment for this disease. RNA interference technology has identified survivin as a potential therapeutic target. Survivin, a member of the inhibitor of apoptosis (IAP) proteins and chromosome passenger complex, is expressed in hematologic malignancies and overexpressed in relapsed pediatric ALL. Our studies show that survivin is uniformly expressed at high levels in multiple pediatric ALL cell lines. Furthermore, silencing of survivin expression in pediatric ALL cell lines as well as primary leukemic blasts reduces viability of these cells. This includes cell lines derived from patients with relapsed disease featuring cytogenetic anomalies such as t(12;21), Philadelphia chromosome t(9;22), t(1;19) as well as a cell line carrying t(17;19) from a patient with de novo ALL. Furthermore, inhibition of survivin increases p53-dependent apoptosis that can be rescued by inhibition of p53. Finally, a screen of randomly selected primary patient samples confirms that survivin-specific small interfering RNA and survivin-targeted drug, YM155, effectively reduce viability of leukemic blasts

    Plant cell culture technology in the cosmetics and food industries : current state and future trends

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    The production of drugs, cosmetics, and food which are derived from plant cell and tissue cultures has a long tradition. The emerging trend of manufacturing cosmetics and food products in a natural and sustainable manner has brought a new wave in plant cell culture technology over the past 10 years. More than 50 products based on extracts from plant cell cultures have made their way into the cosmetics industry during this time, whereby the majority is produced with plant cell suspension cultures. In addition, the first plant cell culture-based food supplement ingredients, such as Echigena Plus and Teoside 10, are now produced at production scale. In this mini review, we discuss the reasons for and the characteristics as well as the challenges of plant cell culture-based productions for the cosmetics and food industries. It focuses on the current state of the art in this field. In addition, two examples of the latest developments in plant cell culture-based food production are presented, that is, superfood which boosts health and food that can be produced in the lab or at home

    Proteomics-Based Systems Biology Modeling of Bovine Germinal Vesicle Stage Oocyte and Cumulus Cell Interaction

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    BACKGROUND: Oocytes are the female gametes which establish the program of life after fertilization. Interactions between oocyte and the surrounding cumulus cells at germinal vesicle (GV) stage are considered essential for proper maturation or 'programming' of oocytes, which is crucial for normal fertilization and embryonic development. However, despite its importance, little is known about the molecular events and pathways involved in this bidirectional communication. METHODOLOGY/PRINCIPAL FINDINGS: We used differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) on bovine GV oocyte and cumulus cells and identified 811 and 1247 proteins in GV oocyte and cumulus cells, respectively; 371 proteins were significantly differentially expressed between each cell type. Systems biology modeling, which included Gene Ontology (GO) and canonical genetic pathway analysis, showed that cumulus cells have higher expression of proteins involved in cell communication, generation of precursor metabolites and energy, as well as transport than GV oocytes. Our data also suggests a hypothesis that oocytes may depend on the presence of cumulus cells to generate specific cellular signals to coordinate their growth and maturation. CONCLUSIONS/SIGNIFICANCE: Systems biology modeling of bovine oocytes and cumulus cells in the context of GO and protein interaction networks identified the signaling pathways associated with the proteins involved in cell-to-cell signaling biological process that may have implications in oocyte competence and maturation. This first comprehensive systems biology modeling of bovine oocytes and cumulus cell proteomes not only provides a foundation for signaling and cell physiology at the GV stage of oocyte development, but are also valuable for comparative studies of other stages of oocyte development at the molecular level

    Low-dose aspirin does not improve ovarian stimulation, endometrial response, or pregnancy rates for in vitro fertilization

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    BACKGROUND: The purpose of this study is to determine if low-dose aspirin improved ovarian stimulation, endometrial response, or IVF pregnancy rates in our program. METHODS: Retrospective analysis of 316 consecutive IVF cycles from 1995 through 2001. Aspirin 80 mg daily was initiated at the start of luteal leuprolide in 72 cycles. The 244 controls received no aspirin during treatment. RESULTS: The live birth rate in aspirin users was 29%, slightly lower compared to 41% in the no aspirin control group (p = 0.07). Implantation rates were 21% with aspirin and 30% in the control population (p = 0.01). There was no difference in the maximal endometrial thickness between aspirin and non-aspirin groups. The two groups were similar regarding age, gonadotropin ampules, embryos, number of embryos transferred, prior parity, diagnosis, use of intracytoplasmic sperm injection, and stimulation protocol. CONCLUSION: Low-dose aspirin was not beneficial to IVF patients in our program. Aspirin does not enhance endometrial thickness, augment the ovarian response, or improve pregnancy rates
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