65 research outputs found

    Severe gastric variceal haemorrhage due to splenic artery thrombosis and consecutive arterial bypass

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    <p>Abstract</p> <p>Background</p> <p>Upper gastrointestinal haemorrhage is mainly caused by ulcers. Gastric varicosis due to portal hypertension can also be held responsible for upper gastrointestinal bleeding. Portal hypertension causes the development of a collateral circulation from the portal to the caval venous system resulting in development of oesophageal and gastric fundus varices. Those may also be held responsible for upper gastrointestinal haemorrhage.</p> <p>Case presentation</p> <p>In this study, we describe the case of a 69-year-old male with recurrent severe upper gastrointestinal bleeding caused by arterial submucosal collaterals due to idiopathic splenic artery thrombosis. The diagnosis was secured using endoscopic duplex ultrasound and angiography. The patient was successfully treated with a laparoscopic splenectomy and complete dissection of the short gastric arteries, resulting in the collapse of the submucosal arteries in the gastric wall. Follow-up gastroscopy was performed on the 12<sup>th </sup>postoperative week and showed no signs of bleeding and a significant reduction in the arterial blood flow within the gastric wall. Subsequent follow-up after 6 months also showed no further gastrointestinal bleeding as well as subjective good quality of life for the patient.</p> <p>Conclusion</p> <p>Submucosal arterial collaterals must be excluded by endosonography via endoscopy in case of recurrent upper gastrointestinal bleeding. Laparoscopic splenectomy provides adequate treatment in preventing any recurrent bleeding, if gastric arterial collaterals are caused by splenic artery thrombosis.</p

    Sensitivity of Global Translation to mTOR Inhibition in REN Cells Depends on the Equilibrium between eIF4E and 4E-BP1

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    Initiation is the rate-limiting phase of protein synthesis, controlled by signaling pathways regulating the phosphorylation of translation factors. Initiation has three steps, 43S, 48S and 80S formation. 43S formation is repressed by eIF2α phosphorylation. The subsequent steps, 48S and 80S formation are enabled by growth factors. 48S relies on eIF4E-mediated assembly of eIF4F complex; 4E-BPs competitively displace eIF4E from eIF4F. Two pathways control eIF4F: 1) mTORc1 phosphorylates and inactivates 4E-BPs, leading to eIF4F formation; 2) the Ras-Mnk cascade phosphorylates eIF4E. We show that REN and NCI-H28 mesothelioma cells have constitutive activation of both pathways and maximal translation rate, in the absence of exogenous growth factors. Translation is rapidly abrogated by phosphorylation of eIF2α. Surprisingly, pharmacological inhibition of mTORc1 leads to the complete dephosphorylation of downstream targets, without changes in methionine incorporation. In addition, the combined administration of mTORc1 and MAPK/Mnk inhibitors has no additive effect. The inhibition of both mTORc1 and mTORc2 does not affect the metabolic rate. In spite of this, mTORc1 inhibition reduces eIF4F complex formation, and depresses translocation of TOP mRNAs on polysomes. Downregulation of eIF4E and overexpression of 4E-BP1 induce rapamycin sensitivity, suggesting that disruption of eIF4F complex, due to eIF4E modulation, competes with its recycling to ribosomes. These data suggest the existence of a dynamic equilibrium in which eIF4F is not essential for all mRNAs and is not displaced from translated mRNAs, before recycling to the next

    Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

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    Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

    Complications of central venous catheterization in critically ill children

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    WOS: 000249493400009PubMed ID: 17875082Background: Placement of central venous catheter is essential in the management of critically ill children. The purpose of the present paper was to evaluate the success rate, mechanical and thrombotic complications and risk factors associated with these complications from different central venous access sites in critically ill children. Methods: A prospective study was undertaken from February 2000 to March 2005 of 369 central venous catheterizations in children in a pediatric intensive care unit. Results: The veins most frequently used were femoral vein (45%), subclavian vein (32.2%), and internal jugular vein (22.8%). Mean +/- SD duration of catheterization was 9.5 +/- 6.5 days. The procedure was performed under emergency conditions in 18% of patients with an overall success rate of 92.4%. The success rate was significantly lower in younger patients with subclavian catheterization. Insertion-related complications were noted, including 33 arterial punctures (8.9%), 27 cases of malposition (7.3%), 19 hematomas (5.2%), 12 cases of minor bleeding (3.3%), and three cases of pneumothorax (0.8%), and they were more common in the subclavian vein than in the internal jugular and femoral vein. Multiple attempts and failed attempts significantly correlated with higher incidence of complications. Maintenance-related complications included obstruction (n = 26; 7%), accidental removal (n = 14; 3.8%), central venous thrombosis (n = 8; 2.2%), subcutaneous extravasation (n = 14; 3.8%), dislodgment (n = 1; 0.25%), and extravascular infusion (n = 1; 0.25%). The frequency of catheter maintenance-related complications was significantly higher in femoral catheterizations and increased significantly with an increase in the duration of catheterization. A total of five serious complications were seen (pneumothorax in three, dislodgment in one and extravascular infusion in one) in the present series. Conclusions: Central venous catheterization in critically ill children is a relatively safe procedure, with a 1.3% rate of serious complications and no mortality. It seems safer to choose initially the femoral or internal jugular vein instead of the subclavian vein because of high success rate without serious insertion-related complications
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