633 research outputs found

    Protocol for PIT: a phase III trial of prophylactic irradiation of tracts in patients with malignant pleural mesothelioma following invasive chest wall intervention.

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    INTRODUCTION: Histological diagnosis of malignant mesothelioma requires an invasive procedure such as CT-guided needle biopsy, thoracoscopy, video-assisted thorascopic surgery (VATs) or thoracotomy. These invasive procedures encourage tumour cell seeding at the intervention site and patients can develop tumour nodules within the chest wall. In an effort to prevent nodules developing, it has been widespread practice across Europe to irradiate intervention sites postprocedure--a practice known as prophylactic irradiation of tracts (PIT). To date there has not been a suitably powered randomised trial to determine whether PIT is effective at reducing the risk of chest wall nodule development. METHODS AND ANALYSIS: In this multicentre phase III randomised controlled superiority trial, 374 patients who can receive radiotherapy within 42 days of a chest wall intervention will be randomised to receive PIT or no PIT. Patients will be randomised on a 1:1 basis. Radiotherapy in the PIT arm will be 21 Gy in three fractions. Subsequent chemotherapy is given at the clinicians' discretion. A reduction in the incidence of chest wall nodules from 15% to 5% in favour of radiotherapy 6 months after randomisation would be clinically significant. All patients will be followed up for up to 2 years with monthly telephone contact and at least four outpatient visits in the first year. ETHICS AND DISSEMINATION: PIT was approved by NRES Committee North West-Greater Manchester West (REC reference 12/NW/0249) and recruitment is currently on-going, the last patient is expected to be randomised by the end of 2015. The analysis of the primary end point, incidence of chest wall nodules 6 months after randomisation, is expected to be published in 2016 in a peer reviewed journal and results will also be presented at scientific meetings and summary results published online. A follow-up analysis is expected to be published in 2018. TRIAL REGISTRATION NUMBER: ISRCTN04240319; NCT01604005; Pre-results

    Voltage-gated potassium channels (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

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    The 6TM family of K channels comprises the voltage-gated KV subfamilies, the EAG subfamily (which includes hERG channels), the Ca2+-activated Slo subfamily (actually with 7TM, termed BK) and the Ca2+-activated SK subfamily. These channels possess a pore-forming α subunit that comprise tetramers of identical subunits (homomeric) or of different subunits (heteromeric). Heteromeric channels can only be formed within subfamilies (e.g. Kv1.1 with Kv1.2; Kv7.2 with Kv7.3). The pharmacology largely reflects the subunit composition of the functional channel

    Voltage-gated potassium channels (Kv) in GtoPdb v.2021.3

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    The 6TM family of K channels comprises the voltage-gated KV subfamilies, the EAG subfamily (which includes hERG channels), the Ca2+-activated Slo subfamily (actually with 7TM, termed BK) and the Ca2+-activated SK subfamily. These channels possess a pore-forming α subunit that comprise tetramers of identical subunits (homomeric) or of different subunits (heteromeric). Heteromeric channels can only be formed within subfamilies (e.g. Kv1.1 with Kv1.2; Kv7.2 with Kv7.3). The pharmacology largely reflects the subunit composition of the functional channel

    Tetramethylpyrazine attenuates spinal cord ischemic injury due to aortic cross-clamping in rabbits

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    BACKGROUND: Lower limb paralysis occurs in 11% of patients after surgical procedure of thoracic or thoracoabdominal aneurysms and is an unpredictable and distressful complication. The aim of this study was to investigate the effects of tetramethylpyrazine (TMP), an intravenous drug made from traditional Chinese herbs, on the neurologic outcome and hisotpathology after transient spinal cord ischemia in rabbits. METHODS: Forty-five male New Zealand white rabbits were anesthetized with isoflurane and spinal cord ischemia was induced for 20 min by infrarenal aortic occlusion. Animals were randomly allocated to one of five groups (n = 8 each). Group C received no pharmacologic intervention. Group P received intravenous infusion of 30 mg·kg(-1) TMP within 30 min before aortic occlusion. Group T(1), Group T(2) and Group T(3) received intravenous infusion of 15, 30 and 60 mg·kg(-1) TMP respectively within 30 min after reperfusion. In the sham group (n = 5), the animals underwent the same procedures as the control group except infrarental aortic unocclusion. Neurologic status was scored by using the Tarlov criteria (in which 4 is normal and 0 is paraplegia) at 4 h, 8 h, 12 h, 24 h, and 48 h after reperfusion. All animals were sacrificed at 48 h after reperfusion and the spinal cords (L(5)) were removed immediately for histopathologic study. RESULTS: All animals in the control group became paraplegic. Neurologic status and histopathology (48 h) in the Groups P, T(2) and T(3) were significantly better than those in the control group (P < 0.05). There was a strong correlation between the final neurologic scores and the number of normal neurons in the anterior spinal cord (r = 0.776, P < 0.01). CONCLUSION: Tetramethylpyrazine significantly reduces neurologic injury related to spinal cord ischemia and reperfusion after aortic occlusion within a certain range of dose

    A Human TREK-1/HEK Cell Line: A Highly Efficient Screening Tool for Drug Development in Neurological Diseases

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    TREK-1 potassium channels are involved in a number of physiopathological processes such as neuroprotection, pain and depression. Molecules able to open or to block these channels can be clinically important. Having a cell model for screening such molecules is of particular interest. Here, we describe the development of the first available cell line that constituvely expresses the TREK-1 channel. The TREK-1 channel expressed by the h-TREK-1/HEK cell line has conserved all its modulation properties. It is opened by stretch, pH, polyunsaturated fatty acids and by the neuroprotective molecule, riluzole and it is blocked by spadin or fluoxetine. We also demonstrate that the h-TREK-1/HEK cell line is protected against ischemia by using the oxygen-glucose deprivation model

    Bronchogenic cyst associated with pericardial defect: Case report and review of the literature

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    Partial defect of the pericardium combined with bronchogenic cyst is a very rare congenital anomaly. We describe the case of a 32-year-old man with a partial defect of the left pericardium and a bronchogenic cyst arising from the border of the pericardial defect. The cyst was successfully resected with the harmonic scalpel by three-port videothoracoscopic approach

    On the Role of the Difference in Surface Tensions Involved in the Allosteric Regulation of NHE-1 Induced by Low to Mild Osmotic Pressure, Membrane Tension and Lipid Asymmetry

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    The sodium-proton exchanger 1 (NHE-1) is a membrane transporter that exchanges Na+ for H+ ion across the membrane of eukaryotic cells. It is cooperatively activated by intracellular protons, and this allosteric regulation is modulated by the biophysical properties of the plasma membrane and related lipid environment. Consequently, NHE-1 is a mechanosensitive transporter that responds to osmotic pressure, and changes in membrane composition. The purpose of this study was to develop the relationship between membrane surface tension, and the allosteric balance of a mechanosensitive transporter such as NHE-1. In eukaryotes, the asymmetric composition of membrane leaflets results in a difference in surface tensions that is involved in the creation of a reservoir of intracellular vesicles and membrane buds contributing to buffer mechanical constraints. Therefore, we took this phenomenon into account in this study and developed a set of relations between the mean surface tension, membrane asymmetry, fluid phase endocytosis and the allosteric equilibrium constant of the transporter. We then used the experimental data published on the effects of osmotic pressure and membrane modification on the NHE-1 allosteric constant to fit these equations. We show here that NHE-1 mechanosensitivity is more based on its high sensitivity towards the asymmetry between the bilayer leaflets compared to mean global membrane tension. This compliance to membrane asymmetry is physiologically relevant as with their slower transport rates than ion channels, transporters cannot respond as high pressure-high conductance fast-gating emergency valves

    Tumours of the thymus: a cohort study of prognostic factors from the European Society of Thoracic Surgeons database

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    OBJECTIVES A retrospective database was developed by the European Society of Thoracic Surgeons, collecting patients submitted to surgery for thymic tumours to analyse clinico-pathological prognostic predictors. METHODS A total of 2151 incident cases from 35 institutions were collected from 1990 to 2010. Clinical-pathological characteristics were analysed, including age, gender, associated myasthenia gravis stage (Masaoka), World Health Organization histology, type of thymic tumour [thymoma, thymic carcinoma (TC), neuroendocrine thymic tumour (NETT)], type of resection (complete/incomplete), tumour size, adjuvant therapy and recurrence. Primary outcome was overall survival (OS); secondary outcomes were the proportion of incomplete resections, disease-free survival and the cumulative incidence of recurrence (CIR). RESULTS A total of 2030 patients were analysed for OS (1798 thymomas, 191 TCs and 41 NETTs). Ten-year OS was 0.73 (95% confidence interval 0.69-0.75). Complete resection (R0) was achieved in 88% of the patients. Ten-year CIR was 0.12 (0.10-0.15). Predictors of shorter OS were increased age (P < 0-001), stage [III vs I HR 2.66, 1.80-3.92; IV vs I hazard ratio (HR) 4.41, 2.67-7.26], TC (HR 2.39, 1.68-3.40) and NETT (HR 2.59, 1.35-4.99) vs thymomas and incomplete resection (HR 1.74, 1.18-2.57). Risk of recurrence increased with tumour size (P = 0.003), stage (III vs I HR 5.67, 2.80-11.45; IV vs I HR 13.08, 5.70-30.03) and NETT (HR 7.18, 3.48-14.82). Analysis using a propensity score indicates that the administration of adjuvant therapy was beneficial in increasing OS (HR 0.69, 0.49-0.97) in R0 resections. CONCLUSIONS Masaoka stages III-IV, incomplete resection and non-thymoma histology showed a significant impact in increasing recurrence and in worsening survival. The administration of adjuvant therapy after complete resection is associated with improved surviva

    The IASLC/ITMIG thymic epithelial tumors staging project: Proposals for the T component for the forthcoming (8th) edition of the TNM classification of malignant tumors

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    Despite longstanding recognition of thymic epithelial neoplasms, there is no official American Joint Committee on Cancer/ Union for International Cancer Control stage classification. This article summarizes proposals for classification of the T component of stage classification for use in the 8th edition of the tumor, node, metastasis classification for malignant tumors. This represents the output of the International Association for the Study of Lung Cancer and the International Thymic Malignancies Interest Group Staging and Prognostics Factor Committee, which assembled and analyzed a worldwide database of 10,808 patients with thymic malignancies from 105 sites. The committee proposes division of the T component into four categories, representing levels of invasion. T1 includes tumors localized to the thymus and anterior mediastinal fat, regardless of capsular invasion, up to and including infiltration through the mediastinal pleura. Invasion of the pericardium is designated as T2. T3 includes tumors with direct involvement of a group of mediastinal structures either singly or in combination: lung, brachiocephalic vein, superior vena cava, chest wall, and phrenic nerve. Invasion of more central structures constitutes T4: aorta and arch vessels, intrapericardial pulmonary artery, myocardium, trachea, and esophagus. Size did not emerge as a useful descriptor for stage classification. This classification of T categories, combined with a classification of N and M categories, provides a basis for a robust tumor, node, metastasis classification system for the 8th edition of American Joint Committee on Cancer/Union for International Cancer Control stage classification

    A Novel Extracytoplasmic Function (ECF) Sigma Factor Regulates Virulence in Pseudomonas aeruginosa

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    Next to the two-component and quorum sensing systems, cell-surface signaling (CSS) has been recently identified as an important regulatory system in Pseudomonas aeruginosa. CSS systems sense signals from outside the cell and transmit them into the cytoplasm. They generally consist of a TonB-dependent outer membrane receptor, a sigma factor regulator (or anti-sigma factor) in the cytoplasmic membrane, and an extracytoplasmic function (ECF) sigma factor. Upon perception of the extracellular signal by the receptor the ECF sigma factor is activated and promotes the transcription of a specific set of gene(s). Although most P. aeruginosa CSS systems are involved in the regulation of iron uptake, we have identified a novel system involved in the regulation of virulence. This CSS system, which has been designated PUMA3, has a number of unusual characteristics. The most obvious difference is the receptor component which is considerably smaller than that of other CSS outer membrane receptors and lacks a β-barrel domain. Homology modeling of PA0674 shows that this receptor is predicted to be a bilobal protein, with an N-terminal domain that resembles the N-terminal periplasmic signaling domain of CSS receptors, and a C-terminal domain that resembles the periplasmic C-terminal domains of the TolA/TonB proteins. Furthermore, the sigma factor regulator both inhibits the function of the ECF sigma factor and is required for its activity. By microarray analysis we show that PUMA3 regulates the expression of a number of genes encoding potential virulence factors, including a two-partner secretion (TPS) system. Using zebrafish (Danio rerio) embryos as a host we have demonstrated that the P. aeruginosa PUMA3-induced strain is more virulent than the wild-type. PUMA3 represents the first CSS system dedicated to the transcriptional activation of virulence functions in a human pathogen
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