Influence of 5-fluorouracil-loaded microsphere formulation on efficient rat glioma radiosensitization

PURPOSE: To determine (i) the efficiency of radiosensitizing 5-FU-loaded microspheres and (ii) the impact of microparticle formulation on response to treatment. METHODS: C6 tumor-bearing rats were stereotactically implanted with microspheres and/or allocated to: control groups (untreated) or treatment (only radiotherapy; fast-release 5-FU microspheres + radiotherapy; slow-release 5-FU microspheres + radiotherapy). The next day, fractionated radiotherapy, limited to the hemibrain, was initiated in all treated animals. The irradiation cycle included 36 Gy, given in 9 sessions for 3 consecutive weeks. Tumor development was assessed by T2-weighted MRI. RESULTS: 5-FU microspheres associated with radiotherapy caused a 47% complete remission rate (9/19) as opposed to the 8% rate (1/12) when radiotherapy alone or 0% in control animals. Drug delivery for 3 weeks produced better survival results (57%) compared to one-week sustained release (41%). MR images showed exponentially increasing tumor volumes during the first half of the radiotherapy cycle, followed by a decrease, and the disappearance of the tumor if survival exceeded 120 days. CONCLUSIONS: 5-FU controlled delivery is a promising strategy for radiosensitizing gliomas. Drug delivery system formulation is unambiguously implicated in both the response to treatment and the limitation of toxic side effects

Elastic properties of grafted microtubules

We use single-particle tracking to study the elastic properties of single microtubules grafted to a substrate. Thermal fluctuations of the free microtubule's end are recorded, in order to measure position distribution functions from which we calculate the persistence length of microtubules with contour lengths between 2.6 and 48 micrometers. We find the persistence length to vary by more than a factor of 20 over the total range of contour lengths. Our results support the hypothesis that shearing between protofilaments contributes significantly to the mechanics of microtubules.Comment: 9 pages, 3 figure

Analysis of salinity tolerance of Vitis vinifera 'Thompson Seedless' transformed with AtNHX1

Several transgenic plant species expressing AtNHX1, coding for a vacuolar Na+/H+ antiporter from Arabidopsis thaliana, have shown their ability to cope with salinity. The aim of this study was to analyze the response of Vitis vinifera cv. 'Thompson Seedless' transformed with AtNHX1 to salt stress, using soil substrate or hydroponic media, and to compare the response with untransformed 'Thompson Seedless' and allegedly tolerant 'Criolla' cultivars: 'Pedro Giménez' and 'Criolla Chica'. 'Thompson Seedless' embryogenic calli were transformed with Agrobacterium tumefaciens carrying AtNHX1 under the control of CaMV 35S promoter. Transgenic and untransformed plants were grown in a greenhouse under hydroponics or in pots with soil, and were subjected to increasing concentrations of sodium chloride (NaCl) up to 150 mM for a period of 7 weeks. Growth and toxicity symptoms were less affected in transgenics as compared to the untransformed grapevines, and transgenic lines had higher shoot length, leaf area and dry weights at the end of the experiment. Root concentrations of Na in transgenics were similar or lower than that observed in untransformed genotypes. Growth impairment and toxicity symptoms were observed in all genotypes under both conditions, but effects were more severe in plants growing with hydroponic culture. Potassium content and shoot to root dry weight ratio decreased with NaCl in hydroponics but not in pots. 'Criolla' cultivars grew less than the other genotypes, although 'Pedro Giménez' always exhibited highest shoot/root ratios

Micronutrients attenuate progression of prostate cancer by elevating the endogenous inhibitor of angiogenesis, Platelet Factor-4

<p>Abstract</p> <p>Background</p> <p>Longstanding evidence implicates an inadequate diet as a key factor in the onset and progression of prostate cancer. The purpose herein was to discover, validate and characterize functional biomarkers of dietary supplementation capable of suppressing the course of prostate cancer <it>in vivo</it>.</p> <p>Methods</p> <p>The <it>Lady </it>transgenic mouse model that spontaneously develops prostate cancer received a diet supplemented with a micronutrient cocktail of vitamin E, selenium and lycopene ad libitum. A proteomic analysis was conducted to screen for serum biomarkers of this dietary supplementation. Candidate peptides were validated and identified by sequencing and analyzed for their presence within the prostates of all mice by immunohistochemistry.</p> <p>Results</p> <p>Dietary supplementation with the combined micronutrients significantly induced the expression of the megakaryocyte-specific inhibitor of angiogenesis, platelet factor-4 (P = 0.0025). This observation was made predominantly in mice lacking tumors and any manifestations associated with progressive disease beyond 37 weeks of life, at which time no survivors remained in the control group (P < 0.0001). While prostates of mice receiving standard chow were enlarged and burdened with poorly differentiated carcinoma, those of mice on the supplemented diet appeared normal. Immunohistochemical analysis revealed marked amplifications of both platelet binding and platelet factor-4 within the blood vessels of prostates from mice receiving micronutrients only.</p> <p>Conclusion</p> <p>We present unprecedented data whereby these combined micronutrients effectively promotes tumor dormancy in early prostate cancer, following initiation mutations that may drive the angiogenesis-dependent response of the tumor, by inducing platelet factor-4 expression and concentrating it at the tumor endothelium through enhanced platelet binding.</p

Bayesian inference on compact binary inspiral gravitational radiation signals in interferometric data

Presented is a description of a Markov chain Monte Carlo (MCMC) parameter estimation routine for use with interferometric gravitational radiational data in searches for binary neutron star inspiral signals. Five parameters associated with the inspiral can be estimated, and summary statistics are produced. Advanced MCMC methods were implemented, including importance resampling and prior distributions based on detection probability, in order to increase the efficiency of the code. An example is presented from an application using realistic, albeit fictitious, data.Comment: submitted to Classical and Quantum Gravity. 14 pages, 5 figure

A

Abstract:&nbsp; The estrogenic action on pituitary cell growth is widely known. We have previously demonstrated the activation of the antioxidant pathway of phosphorylated erythroid 2-derived nuclear factor 2 (p-Nrf2) in response to DNA damage by 17β-estradiol (E2). In this study we analyzed the impact of E2 on the tumoral suppressor p53 and cell cycle regulator p21 activation, as well as the damage response in pituitary cells in vitro. Pituitary tumour development was induced in adult male Wistar rats by subcutaneous implantation of silastic capsules containing estradiol benzoate (30mg) for 10 days (E10; n = 5). The control group was implanted with empty capsules (n=5). Subsequently, pituitary glands were collected, with cells being cultured and exposed to E2 (1-10-100nM) for 15, 30 and 60 min. The p53 and p21 protein levels were determined by western blot. By immunofluorescence, the co-expression of prolactin (PRL)/p-Nrf2 and growth hormone (GH)/p-Nrf2 was evaluated to determinate the cell type involved in the activation of the oxidative damage response. Statistical analysis: ANOVA-Fischer (p &lt;0.05). Under tumoral contexts, a significant increase in p53 protein at the cytoplasmic level was detected after 15 and 30 min of treatment with E2 (1nM). After supraphysiological concentrations (10-100nM), this response was observed after 30 and 60 min. At nuclear level, we only detected an increase in p53 at 15 min, regardless of the dose. The p2 expression showed a similar profile in both subcellular compartments, with significant increases after 15 and 30 min of exposure with 1nM E2 and 30 and 60 min with supraphysiological doses. In normal cells cultures we did not observe significant changes in the expression of both markers. The number of lactotroph tumoral cells co-expressing PRL/p-Nrf2 increased significantly at 30 min compared to supraphysiological doses of E2. No changes were detected in the expression of GH/p-Nrf2 in GH cells. In tumoral pituitary cells, the pro-oxidant action induced by E2 triggers the activation of p53 and p21 in order to repair DNA damage, through the stabilization of Nrf2. This response would mainly have an impact on PRL tumoral cells. These mechanisms could guarantee the cell viability, thus regulating pituitary tumor development.Resumen:&nbsp; Es ampliamente conocida la acción estrogénica sobre el crecimiento celular hipofisario. Previamente demostramos la activación de la vía antioxidante del factor nuclear 2 derivado del eritroide 2 fosforilado (Nrf2-p) en respuesta al daño del ADN por 17β-estradiol (E2). Analizamos entonces, el impacto del E2 sobre la activación del supresor tumoral p53 y el regulador del ciclo celular p21, y la respuesta al daño en células hipofisarias in vitro. Indujimos el desarrollo tumoral hipofisario en ratas Wistar macho adultas mediante la implantación subcutánea de cápsulas de silástico conteniendo benzoato de estradiol (30 mg) durante 10 días (E10; n=5). El grupo control fue implantado con cápsulas vacía (n=5). Posteriormente, extrajimos las adenohipófisis, cultivamos sus células y fueron expuestas a E2 (1-10-100nM) por 15, 30 y 60min. Determinamos los niveles proteicos de p53 y p21 por western blot. Por inmunofluorescencia, evaluamos la co-expresión de Prolactina (PRL)/Nrf2-p y hormona de crecimiento (GH)/Nrf2-p para determinar el tipo celular involucrado con activación de respuesta al daño oxidativo. Análisis estadístico: ANOVA-Fischer (p &lt;0,05). En contextos tumorales, detectamos un aumento significativo de la proteína p53 a nivel citoplasmático luego de 15 y 30 min de tratamiento con E2 (1nM); frente a concentraciones suprafisiológicas (10-100nM) esta respuesta se observó luego de 30 y 60 min. A nivel nuclear, detectamos un aumento de p53 solo a los 15 min, de manera independiente de la dosis. La expresión de p21 mostró un perfil similar en ambos compartimientos subcelulares con incrementos significativos luego de 15 y 30 min de exposición con E2 1nM y 30 y 60 min con dosis suprafisiológicas. En cultivos normales no observamos cambios significativos en la expresión de ambos marcadores. El número de células lactotropas tumorales que co-expresaron PRL/Nrf2-p aumentó significativamente a los 30 min frente a dosis suprafisiológicas de E2; sin detectarse modificaciones en la expresión de GH/Nrf2-p en células somatotropas. En células hipofisarias tumorales, la acción pro-oxidante inducida por E2 desencadena la activación de p53 y de p21 a fin de reparar el daño del ADN, vía estabilización de Nrf2. Esta respuesta impactaría principalmente sobre células lactotropas tumorales. Mediante estos mecanismos se garantizaría la viabilidad celular, regulando el desarrollo tumoral hipofisario.

High-throughput sequencing and analysis of the gill tissue transcriptome from the deep-sea hydrothermal vent mussel Bathymodiolus azoricus

© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in BMC Genomics 11 (2010): 559, doi:10.1186/1471-2164-11-559.Bathymodiolus azoricus is a deep-sea hydrothermal vent mussel found in association with large faunal communities living in chemosynthetic environments at the bottom of the sea floor near the Azores Islands. Investigation of the exceptional physiological reactions that vent mussels have adopted in their habitat, including responses to environmental microbes, remains a difficult challenge for deep-sea biologists. In an attempt to reveal genes potentially involved in the deep-sea mussel innate immunity we carried out a high-throughput sequence analysis of freshly collected B. azoricus transcriptome using gills tissues as the primary source of immune transcripts given its strategic role in filtering the surrounding waterborne potentially infectious microorganisms. Additionally, a substantial EST data set was produced and from which a comprehensive collection of genes coding for putative proteins was organized in a dedicated database, "DeepSeaVent" the first deep-sea vent animal transcriptome database based on the 454 pyrosequencing technology. A normalized cDNA library from gills tissue was sequenced in a full 454 GS-FLX run, producing 778,996 sequencing reads. Assembly of the high quality reads resulted in 75,407 contigs of which 3,071 were singletons. A total of 39,425 transcripts were conceptually translated into amino-sequences of which 22,023 matched known proteins in the NCBI non-redundant protein database, 15,839 revealed conserved protein domains through InterPro functional classification and 9,584 were assigned with Gene Ontology terms. Queries conducted within the database enabled the identification of genes putatively involved in immune and inflammatory reactions which had not been previously evidenced in the vent mussel. Their physical counterpart was confirmed by semi-quantitative quantitative Reverse-Transcription-Polymerase Chain Reactions (RT-PCR) and their RNA transcription level by quantitative PCR (qPCR) experiments. We have established the first tissue transcriptional analysis of a deep-sea hydrothermal vent animal and generated a searchable catalog of genes that provides a direct method of identifying and retrieving vast numbers of novel coding sequences which can be applied in gene expression profiling experiments from a non-conventional model organism. This provides the most comprehensive sequence resource for identifying novel genes currently available for a deep-sea vent organism, in particular, genes putatively involved in immune and inflammatory reactions in vent mussels. The characterization of the B. azoricus transcriptome will facilitate research into biological processes underlying physiological adaptations to hydrothermal vent environments and will provide a basis for expanding our understanding of genes putatively involved in adaptations processes during post-capture long term acclimatization experiments, at "sea-level" conditions, using B. azoricus as a model organism.We acknowledge the Portuguese Foundation for Science and Technology, FCT-Lisbon and the Regional Azorean Directorate for Science and Technology, DRCT-Azores, for pluri-annual and programmatic PIDDAC and FEDER funding to IMAR/DOP Research Unit #531 and the Associated Laboratory #9 (ISR-Lisboa); the Luso-American Foundation FLAD (Project L-V- 173/2006); the Biotechnology and Biomedicine Institute of the Azores (IBBA), project M.2.1.2/I/029/2008-BIODEEPSEA and the project n° FCOMP-01-0124- FEDER-007376 (ref: FCT PTDC/MAR/65991/2006-IMUNOVENT; coordinated by RB) under the auspices of the COMPETE program