221 research outputs found
The association between isolated oligohydramnios at term and pregnancy outcome and perinatal outcome in case of isolated oligohydramnosis: a retrospective analysis
Background: Current study was carried out to assess the impact of isolated oligohydramnios on perinatal outcomes and mode of delivery.Methods: A retrospective observational cohort study was conducted at term pregnancy with sonographic finding of isolated oligohydramnios (AFI 5-25 cm).Results: When compared to the normal AFI, women with oligohydramnios had significantly lower birth weight babies and were delivered at a significantly earlier gestational age. However there was no difference in the APGAR scores at birth and NICU admissions between the two groups. Reactive NST had more chances of good APGAR score at 1 and 5 minute and that lower the AFI more the probability of nonreactive NST and abnormal Doppler. The number of inductions and caesareans done for foetal reasons were significantly higher in the exposed group.Conclusions: Obstetric and perinatal outcome remains similar in both isolated oligohydramnios with reactive NST as well as in patients with normal amniotic fluid index. Isolated oligohydramnios is not associated with adverse perinatal outcomes. However, it increases the risk for labour induction and caesarean section
Status report on the folded tandem ion accelerator at BARC
The folded tandem ion accelerator (FOTIA) facility set up at BARC has become operational. At present, it is used for elemental analysis studies using the Rutherford backscattering technique. The beams of 1H, 7Li, 12C, 16O and 19F have been accelerated up to terminal voltages of about 3 MV and are available for experiments. The terminal voltage is stable within ±2 kV. In this paper, present status of the FOTIA and future plans are discussed
Rb regulates fate choice and lineage commitment in vivo
February 1, 2011Mutation of the retinoblastoma gene (RB1) tumour suppressor occurs in one-third of all human tumours and is particularly associated with retinoblastoma and osteosarcoma[superscript 1]. Numerous functions have been ascribed to the product of the human RB1 gene, the retinoblastoma protein (pRb). The best known is pRb’s ability to promote cell-cycle exit through inhibition of the E2F transcription factors and the transcriptional repression of genes encoding cell-cycle regulators[superscript 1]. In addition, pRb has been shown in vitro to regulate several transcription factors that are master differentiation inducers[superscript 2]. Depending on the differentiation factor and cellular context, pRb can either suppress or promote their transcriptional activity. For example, pRb binds to Runx2 and potentiates its ability to promote osteogenic differentiation in vitro[superscript 3]. In contrast, pRb acts with E2F to suppress peroxisome proliferator-activated receptor γ subunit (PPAR-γ), the master activator of adipogenesis[superscript 4, 5]. Because osteoblasts and adipocytes can both arise from mesenchymal stem cells, these observations suggest that pRb might play a role in the choice between these two fates. However, so far, there is no evidence for this in vivo. Here we use mouse models to address this hypothesis in mesenchymal tissue development and tumorigenesis. Our data show that Rb status plays a key role in establishing fate choice between bone and brown adipose tissue in vivo.National Cancer Institute (U.S.) (Grant)National Institutes of Health (U.S.) (Grant
Oligomerization of the E. coli Core RNA Polymerase: Formation of (α2ββ'ω)2–DNA Complexes and Regulation of the Oligomerization by Auxiliary Subunits
In this work, using multiple, dissimilar physico-chemical techniques, we demonstrate that the Escherichia coli RNA polymerase core enzyme obtained through a classic purification procedure forms stable (α2ββ'ω)2 complexes in the presence or absence of short DNA probes. Multiple control experiments indicate that this self-association is unlikely to be mediated by RNA polymerase-associated non-protein molecules. We show that the formation of (α2ββ'ω)2 complexes is subject to regulation by known RNA polymerase interactors, such as the auxiliary SWI/SNF subunit of RNA polymerase RapA, as well as NusA and σ70. We also demonstrate that the separation of the core RNA polymerase and RNA polymerase holoenzyme species during Mono Q chromatography is likely due to oligomerization of the core enzyme. We have analyzed the oligomeric state of the polymerase in the presence or absence of DNA, an aspect that was missing from previous studies. Importantly, our work demonstrates that RNA polymerase oligomerization is compatible with DNA binding. Through in vitro transcription and in vivo experiments (utilizing a RapAR599/Q602 mutant lacking transcription-stimulatory function), we demonstrate that the formation of tandem (α2ββ'ω)2–DNA complexes is likely functionally significant and beneficial for the transcriptional activity of the polymerase. Taken together, our findings suggest a novel structural aspect of the E. coli elongation complex. We hypothesize that transcription by tandem RNA polymerase complexes initiated at hypothetical bidirectional “origins of transcription” may explain recurring switches of the direction of transcription in bacterial genomes
Charge transport mechanisms in monovalent doped mixed valent manganites
Abstract In this communication, we report the results of the studies on structural and transport properties of monovalent Na + doped La 1-x Na x MnO 3 (LNMO; x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) manganites synthesized by conventional ceramic method. X-ray diffraction (XRD) and Rietveld refinements reveal the single phasic nature of LNMO manganites without any detectable impurity within the measurement range. Temperature dependent resistivity, under different applied magnetic fields, has been performed on LNMO samples. Samples understudy exhibit metal to insulator (semiconductor) transition at temperature T P which is strongly influenced by the substitution of Na + at La 3+ site. -T plots also exhibit resistivity upturn behavior at low temperature well below 40K under all the applied fields. Variation in T P and resistivity has been discussed in the context of the competition between the transport favoring tolerance factor and zener double exchange (ZDE) mechanism and transport degrading Jahn-Teller (JT) and size variance effects. In order to understand the mechanisms responsible for the charge transport in metallic and semiconducting regions and to explore the possible electronic processes responsible for the observed low temperature resistivity minima in all the presently studied LNMO manganites, various models have been employed. It has been found that VRH mechanism gets successfully fitted to the resistivity data in the semiconducting region while ZDE polynomial law is responsible for the charge conduction in metallic region for all the presently studied LNMO samples. A strong dependence of activation energy on the Na + -content as well as applied magnetic field has been discussed in the context of variation and interrelations between the structural parameters. Charge conduction in metallic region has been discussed in the light of electron-phonon interactions which is influenced by the Na + -content and applied magnetic field. Electrostatic blockade model has been employed to understand the low temperature resistivity minima behavior. Blocking energy for the charge carriers shows a dependence on the magnetic energy provided to the charge carriers. Present study can be useful to understand and to control the charge conduction in the manganites and hence to design the manganite based thin film devices for various spintronic applications
Molecular alterations as target for therapy in metastatic osteosarcoma: a review of literature
Treating metastatic osteosarcoma (OS) remains a challenge in oncology. Current treatment strategies target the primary tumour rather than metastases and have a limited efficacy in the treatment of metastatic disease. Metastatic cells have specific features that render them less sensitive to therapy and targeting these features might enhance the efficacy of current treatment. A detailed study of the biological characteristics and behaviour of metastatic OS cells may provide a rational basis for innovative treatment strategies. The aim of this review is to give an overview of the biological changes in metastatic OS cells and the preclinical and clinical efforts targeting the different steps in OS metastases and how these contribute to designing a metastasis directed treatment for OS
Detection and Characterization of CD133+ Cancer Stem Cells in Human Solid Tumours
Osteosarcoma is the most common primary tumour of bone. Solid tumours are made of heterogeneous cell populations, which display different goals and roles in tumour economy. A rather small cell subset can hold or acquire stem potentials, gaining aggressiveness and increasing expectancy of recurrence. The CD133 antigen is a pentaspan membrane glycoprotein, which has been proposed as a cancer stem cell marker, since it has been previously demonstrated to be capable of identifying a cancer initiating subpopulation in brain, colon, melanoma and other solid tumours. Therefore, our aim was to observe the possible presence of cells expressing the CD133 antigen within solid tumour cell lines of osteosarcoma and, then, understand their biological characteristics and performances.In this study, using SAOS2, MG63 and U2OS, three human sarcoma cell lines isolated from young Caucasian subjects, we were able to identify and characterize, among them, CD133+ cells showing the following features: high proliferation rate, cell cycle detection in a G2\M phase, positivity for Ki-67, and expression of ABCG2 transporters. In addition, at the FACS, we were able to observe the CD133+ cell fraction showing side population profile and forming sphere-clusters in serum-free medium with a high clonogenic efficiency.Taken together, our findings lead to the thought that we can assume that we have identified, for the first time, CD133+ cells within osteosarcoma cell lines, showing many features of cancer stem cells. This can be of rather interest in order to design new therapies against the bone cancer
A comprehensive candidate gene approach identifies genetic variation associated with osteosarcoma
<p>Abstract</p> <p>Background</p> <p>Osteosarcoma (OS) is a bone malignancy which occurs primarily in adolescents. Since it occurs during a period of rapid growth, genes important in bone formation and growth are plausible modifiers of risk. Genes involved in DNA repair and ribosomal function may contribute to OS pathogenesis, because they maintain the integrity of critical cellular processes. We evaluated these hypotheses in an OS association study of genes from growth/hormone, bone formation, DNA repair, and ribosomal pathways.</p> <p>Methods</p> <p>We evaluated 4836 tag-SNPs across 255 candidate genes in 96 OS cases and 1426 controls. Logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI).</p> <p>Results</p> <p>Twelve SNPs in growth or DNA repair genes were significantly associated with OS after Bonferroni correction. Four SNPs in the DNA repair gene <it>FANCM </it>(ORs 1.9-2.0, <it>P </it>= 0.003-0.004) and 2 SNPs downstream of the growth hormone gene <it>GH1 </it>(OR 1.6, <it>P </it>= 0.002; OR 0.5, <it>P </it>= 0.0009) were significantly associated with OS. One SNP in the region of each of the following genes was significant: <it>MDM2</it>, <it>MPG</it>, <it>FGF2</it>, <it>FGFR3</it>, <it>GNRH2</it>, and <it>IGF1</it>.</p> <p>Conclusions</p> <p>Our results suggest that several SNPs in biologically plausible pathways are associated with OS. Larger studies are required to confirm our findings.</p
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