594 research outputs found
Gastric cancer surgery: Billroth I or Billroth II for distal gastrectomy?
<p>Abstract</p> <p>Background</p> <p>The selection of an anastomosis method after a distal gastrectomy is a highly debatable topic; however, the available documentation lacks the necessary research based on a comparison of early postoperative complications. This study was conducted to investigate the difference of early postoperative complications between Billroth I and Billroth II types of anastomosis for distal gastrectomies.</p> <p>Methods</p> <p>A total of 809 patients who underwent distal gastrectomies for gastric cancer during four years were included in the study. The only study endpoint was analysis of in-patients' postoperative complications. The risk adjusted complication rate was compared by POSSUM (Physiological and operative severity score for enumeration of morbidity and mortality) and the severity of complications was compared by Rui Jin Hospital classification of complication.</p> <p>Results</p> <p>Complication rate of Billroth II type of anastomosis was almost double of that in Billroth I (P = 0.000). Similarly, the risk adjusted complication rate was also higher in Billroth II group. More severe complications were observed and the postoperative duration was significantly longer in Billroth II type (P = 0.000). Overall expenditure was significantly higher in Billroth II type (P = 0.000).</p> <p>Conclusion</p> <p>Billroth II method of anastomosis was associated with higher rate of early postoperative complications. Therefore, we conclude that the Billroth I method should be the first choice after a distal gastrectomy as long as the anatomic and oncological environment of an individual patient allows us to perform it. However more prospective studies should be designed to compare the overall surgical outcomes of both anastomosis methods.</p
Inhibition of NOS- like activity in maize alters the expression of genes involved in H2O2 scavenging and glycine betaine biosynthesis
Nitric oxide synthase-like activity contributes to the production of nitric oxide in plants, which controls
plant responses to stress. This study investigates if changes in ascorbate peroxidase enzymatic
activity and glycine betaine content in response to inhibition of nitric oxide synthase-like activity are
associated with transcriptional regulation by analyzing transcript levels of genes (betaine aldehyde
dehydrogenase) involved in glycine betaine biosynthesis and those encoding antioxidant enzymes
(ascorbate peroxidase and catalase) in leaves of maize seedlings treated with an inhibitor of nitric
oxide synthase-like activity. In seedlings treated with a nitric oxide synthase inhibitor, transcript levels
of betaine aldehyde dehydrogenase were decreased. In plants treated with the nitric oxide synthase
inhibitor, the transcript levels of ascorbate peroxidase-encoding genes were down-regulated. We thus
conclude that inhibition of nitric oxide synthase-like activity suppresses the expression of ascorbate
peroxidase and betaine aldehyde dehydrogenase genes in maize leaves. Furthermore, catalase activity
was suppressed in leaves of plants treated with nitric oxide synthase inhibitor; and this corresponded
with the suppression of the expression of catalase genes. We further conclude that inhibition of nitric
oxide synthase-like activity, which suppresses ascorbate peroxidase and catalase enzymatic activities,
results in increased H2O2 content
Carrageenan-based hydrogels for the controlled delivery of PDGF-BB in bone tissue engineering applications
One of the major drawbacks found in most bone tissue engineering approaches developed so far consists in the
lack of strategies to promote vascularisation. Some studies have addressed different issues that may enhance
vascularisation in tissue engineered constructs, most of them involving the use of growth factors (GFs) that are
involved in the restitution of the vascularity in a damaged zone. The use of sustained delivery systems might also
play an important role in the re-establishment of angiogenesis. In this study, !-carrageenan, a naturally occurring
polymer, was used to develop hydrogel beads with the ability to incorporate GFs with the purpose of establishing
an effective angiogenesis mechanism. Some processing parameters were studied and their influence on the final
bead properties was evaluated. Platelet derived growth factor (PDGF-BB) was selected as the angiogenic factor
to incorporate in the developed beads, and the results demonstrate the achievement of an efficient encapsulation
and controlled release profile matching those usually required for the development of a fully functional vascular
network. In general, the obtained results demonstrate the potential of these systems for bone tissue engineering
applications.This work was supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283), the European STREP HIPPOCRATES (NMP3-CT-2003-505758), and by the Portuguese Foundation for Science and Technology (FCT) through the project PTDC/FIS/68517/2006 and through the V. Espirito Santo's Ph.D. grant (SFRH/BD/39486/2007)
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
Targeting Several CAG Expansion Diseases by a Single Antisense Oligonucleotide
To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion in the HTT gene, which results in an expansion of a glutamine stretch at the N-terminal end of the huntingtin protein. This polyglutamine expansion plays a central role in the disease and results in the accumulation of cytoplasmic and nuclear aggregates. Here, we make use of modified 2′-O-methyl phosphorothioate (CUG)n triplet-repeat antisense oligonucleotides to effectively reduce mutant huntingtin transcript and protein levels in patient-derived Huntington's disease fibroblasts and lymphoblasts. The most effective antisense oligonucleotide, (CUG)7, also reduced mutant ataxin-1 and ataxin-3 mRNA levels in spinocerebellar ataxia 1 and 3, respectively, and atrophin-1 in dentatorubral-pallidoluysian atrophy patient derived fibroblasts. This antisense oligonucleotide is not only a promising therapeutic tool to reduce mutant huntingtin levels in Huntington's disease but our results in spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy cells suggest that this could also be applicable to other polyglutamine expansion disorders as well
Desynchronization of Neocortical Networks by Asynchronous Release of GABA at Autaptic and Synaptic Contacts from Fast-Spiking Interneurons
An activity-dependent long-lasting asynchronous release of GABA from identified fast-spiking inhibitory neurons in the neocortex can impair the reliability and temporal precision of activity in a cortical network
p53 Regulates Cell Cycle and MicroRNAs to Promote Differentiation of Human Embryonic Stem Cells
Multiple studies show that tumor suppressor p53 is a barrier to dedifferentiation; whether this is strictly due to repression of proliferation remains a subject of debate. Here, we show that p53 plays an active role in promoting differentiation of human embryonic stem cells (hESCs) and opposing self-renewal by regulation of specific target genes and microRNAs. In contrast to mouse embryonic stem cells, p53 in hESCs is maintained at low levels in the nucleus, albeit in a deacetylated, inactive state. In response to retinoic acid, CBP/p300 acetylates p53 at lysine 373, which leads to dissociation from E3-ubiquitin ligases HDM2 and TRIM24. Stabilized p53 binds CDKN1A to establish a G1 phase of cell cycle without activation of cell death pathways. In parallel, p53 activates expression of miR-34a and miR-145, which in turn repress stem cell factors OCT4, KLF4, LIN28A, and SOX2 and prevent backsliding to pluripotency. Induction of p53 levels is a key step: RNA-interference-mediated knockdown of p53 delays differentiation, whereas depletion of negative regulators of p53 or ectopic expression of p53 yields spontaneous differentiation of hESCs, independently of retinoic acid. Ectopic expression of p53R175H, a mutated form of p53 that does not bind DNA or regulate transcription, failed to induce differentiation. These studies underscore the importance of a p53-regulated network in determining the human stem cell state
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