4,513 research outputs found
Laparoscopic hysterectomy with or without pelvic lymphadenectomy or sampling in a high-risk series of patients with endometrial cancer
BACKGROUND: The purpose of the study was to determine the outcome of all patients with endometrial adenocarcinoma cancer treated by laparoscopic hysterectomy at our institution, many of whom were high-risk for surgery. METHODS: Data was collected by a retrospective search of the case notes and Electronic Patient Records of the thirty eight patients who underwent laparoscopic hysterectomy for endometrial cancer at our institutions. RESULTS: The median body mass index was 30 (range 19–67). Comorbidities were present in 76% (29 patients); 40% (15 patients) had a single comorbid condition, whilst 18% (7 patients) had two, and a further 18% (7 patients) had more than two. Lymphadenectomy was performed in 45% (17 patients), and lymph node sampling in 21% (8 patients). Median operating time was 210 minutes (range 70–360 minutes). Median estimated blood loss was 200 ml (range 50–1000 ml). There were no intraoperative complications. Post-operative complications were seen in 21% (2 major, 6 minor). Blood transfusion was required in 5% (2 patients). The median stay was 4 post-operative nights (range 1–25 nights). In those patients undergoing lymphadenectomy, the mean number of nodes taken was fifteen (range 8–26 nodes). The pathological staging was FIGO stage I 76% (29 patients), stage II 8% (3 patients), stage III 16% (6 patients). The pathological grade was G1 31% (16 patients), G2 45% (17 patients), G3 24% (8 patients). CONCLUSION: Laparoscopic hysterectomy can be safely carried out in patients at high risk for surgery, with no compromise in terms of outcomes, whilst providing all the benefits inherent in minimal access surgery
Endothelin and cardiac arrhythmias: do endothelin antagonists have a therapeutic potential as antiarrhythmic drugs?
Endothelin-1 (ET-1), the predominant isoform of the ET peptide family and a potent vasoconstrictor, has been shown to aggravate ischemia-induced ventricular arrhythmias. However, there is also evidence that ET-1 may have a direct arrhythmogenic action that is not solely attributable to myocardial ischemia. Proposed mechanisms for the arrhythmogenic effects of ET-1 are prolongation or increased dispersion of monophasic action potential duration, QT prolongation, development of early afterdepolarizations, acidosis, and augmentation of cellular injury. As for an ionic basis for the observed electrophysiologic effects, ET-induced Ca2+ release from intracellular stores, generation of inositol triphosphate, inhibition of delayed rectifier K+ current, and stimulation of the Na+/H+ exchanger may be involved. Recently, some studies have shown that ET receptor antagonists, which promise to be powerful tools in cardiovascular medicine, may also demonstrate antiarrhythmic properties. This review describes the current state of knowledge on the interactions between the ET system and cardiac arrhythmias, and discusses the therapeutic potential of ET antagonists as antiarrhythmic drug
Chronic ETA receptor blockade prevents endothelial dysfunction of small arteries in apolipoprotein E-deficient mice
Objective: This study investigated whether endothelial dysfunction occurs in mesenteric arteries of apoE-deficient mice and determined the role of endothelin (ET)-1, which is increased in human atherosclerosis, using an orally active endothelin ETA receptor antagonist. Methods: ApoE-deficient and C57BL/6J control mice were fed for 30 weeks with normal chow or high-fat Western-type diet alone or in combination with darusentan (LU135252; 50 mg/kg/day). Vasomotor reactivity of isolated small mesenteric arteries (I.D. 200-250 μm) was studied in vitro under perfused and pressurized conditions. Results: In both mouse strains, about one fourth of the endothelium-dependent relaxant response to acetylcholine was insensitive to inhibition by l-NAME and indomethacin. In mesenteric arteries of apoE-deficient mice on Western-type diet, increased intima-media thickness and levels of endothelin-1 protein were observed. In addition, NO-mediated endothelium-dependent relaxation to acetylcholine was reduced without affecting l-NAME/indomethacin insensitive relaxation and contractions to endothelin-1 and serotonin were enhanced. Treatment with darusentan normalized vascular structure, NO-mediated relaxation to acetylcholine and contractions to endothelin-1 and serotonin without affecting blood pressure or plasma cholesterol levels. Conclusions: Severe hypercholesterolemia in apoE-deficient mice is associated with attenuation of NO-mediated relaxation to acetylcholine and increased vascular endothelin-1 content. Chronic ETA receptor blockade may provide a new therapeutic approach to improve NO-mediated endothelium-dependent vasomotion in small arterie
Optical vortex trap for resonant confinement of metal nanoparticles
The confinement and controlled movement of metal nanoparticles and nanorods is an emergent area within optical micromanipulation. In this letter we experimentally realise a novel trapping geometry near the plasmon resonance using an annular light field possessing a helical phasefront that confines the nanoparticle to the vortex core (dark) region. We interpret our data with a theoretical framework based upon the Maxwell stress tensor formulation to elucidate the total forces upon nanometric particles near the particle plasmon resonance. Rotation of the particle due to orbital angular momentum transfer is observed. This geometry may have several advantages for advanced manipulation of metal nanoparticles
Muon-Induced Background Study for Underground Laboratories
We provide a comprehensive study of the cosmic-ray muon flux and induced
activity as a function of overburden along with a convenient parameterization
of the salient fluxes and differential distributions for a suite of underground
laboratories ranging in depth from 1 to 8 km.w.e.. Particular attention
is given to the muon-induced fast neutron activity for the underground sites
and we develop a Depth-Sensitivity-Relation to characterize the effect of such
background in experiments searching for WIMP dark matter and neutrinoless
double beta decay.Comment: 18 pages, 28 figure
Testing the Meson Cloud Model in Inclusive Meson Production
We have applied the Meson Cloud Model to calculate inclusive momentum spectra
of pions and kaons produced in high energy proton-proton and proton-nucleus
collisions. For the first time these data are used to constrain the cloud
cut-off parameters. We show that it is possible to obtain a reasonable
description of data, especially the large () part of the
spectrum and at the same time describe (partially) the E866 data on and . We also discuss the relative strength of the
and vertices. We find out that the corresponding cut-off
parameters should be both soft and should not differ by more than 200 MeV from
each other. An additional source (other than the meson cloud) of sea antiquark
asymmetry, seems to be necessary to completely explain the data. A first
extension of the MCM to proton nucleus collisions is discussed.Comment: 14 pages, Latex, 6 ps figures. Submitted to Phys. Rev.
The dilution peak, metallicity evolution, and dating of galaxy interactions and mergers
Strong inflows of gas from the outer disk to the inner kiloparsecs are
induced during the interaction of disk galaxies. This inflow of relatively
low-metallicity gas dilutes the metallicity of the circumnuclear gas. We have
investigated several aspects of the process as the timing and duration of the
dilution and its correlation with the induced star formation. We analysed major
(1:1) gas-rich interactions and mergers, spanning a range of initial orbital
characteristics. Star formation and metal enrichment from SNe are included in
our model. Our results show that the strongest trend is between the star
formation rate and the dilution of the metals in the nuclear region; i.e., the
more intense the central burst of star formation, the more the gas is diluted.
This trend comes from strong inflows of relatively metal-poor gas from the
outer regions of both disks, which fuels the intense star formation and lowers
the overall metallicity for a time. The strong inflows happen on timescales of
about 10^8 years or less, and the most intense star formation and lowest gas
phase metallicities are seen generally after the first pericentre passage. As
the star formation proceeds and the merger advances, the dilution reduces and
enrichment becomes dominant - ultimately increasing the metallicity of the
circumnuclear gas to a level higher than the initial metallicities of the
merging galaxies. The "fly-bys" - pairs that interact but do not merge - also
cause some dilution. We even see some dilution early in the merger or in the
"fly-bys" and thus do not observe a strong trend between the nuclear
metallicities and separation in our simulations until the merger is well
advanced. We also analyse the O and Fe enrichment of the ISM, and show that the
evolution of the alpha/Fe ratios, as well as the dilution of the central gas
metallicity, can be used as a clock for "dating" the interaction.Comment: 13 pages, 11 figures, A&A in press. Final version after language
editin
The Zurich Environmental Study (ZENS) of galaxies in groups along the cosmic web. V. properties and frequency of merging satellites and centrals in different environments
We use the Zurich ENvironmental Study (ZENS) database to investigate the
environmental dependence of the merger fraction and merging galaxy
properties in a sample of ~1300 group galaxies with and
0.05<z<0.0585. In all galaxy mass bins investigated in our study, we find that
decreases by a factor of ~2-3 in groups with halo masses
relative to less massive systems, indicating a
suppression of merger activity in large potential wells. In the fiducial case
of relaxed groups only, we measure a variation dex, which is almost independent of galaxy mass
and merger stage. At galaxy masses , most mergers are dry
accretions of quenched satellites onto quenched centrals, leading to a strong
increase of with decreasing group-centric distance at these mass
scales.Both satellite and central galaxies in these high mass mergers do not
differ in color and structural properties from a control sample of nonmerging
galaxies of equal mass and rank. At galaxy masses , where
we mostly probe satellite-satellite pairs and mergers between star-forming
systems, close pairs (projected distance kpc) show instead
enhanced (specific) star formation rates and
larger sizes than similar mass, nonmerging satellites. The increase in both
size and SFR leads to similar surface star-formation densities in the merging
and control-sample satellite populations.Comment: Published in ApJ, 797, 12
Thread embedded into penile tissue over time as an unusual hair thread tourniquet injury to the penis: a case report
<p>Abstract</p> <p>Introduction</p> <p>Hair thread tourniquet syndrome has been recognized since the 1960s. Since then, sporadic reports have appeared in the literature describing different degrees of strangulation and/or amputation of the penis caused by a hair thread being inadvertently tied around the penis.</p> <p>Case presentation</p> <p>A 9-year-old boy presented with a 3-year history of hair thread tourniquet injury to his penis. Instead of the usual strangulation or amputation, the tourniquet had become embedded into the penile tissue, manifesting with exuberant granulation tissue and a tight urethral stricture. At surgery, the intact tourniquet was still in place, embedded in dense fibrous tissue and associated with a dense urethral fibrosis which measured about 2 cm long. The tourniquet was divided and removed, the fibrotic urethra excised and a distal penile pedicled skin flap used to perform a single-stage substitution urethroplasty. The patient has been voiding well for 28 months.</p> <p>Conclusion</p> <p>This case is unusual and is the first report of its kind. It is also the first report of a hair thread tourniquet as the cause of pediatric penile injury in Nigeria.</p
Dantrolene for the Prevention and Treatment of Cerebral Vasospasm after Subarachnoid Hemorrhage – a Randomized Placebo-Controlled Trial to assess Safety, Tolerability and Feasibility
Introduction: Dantrolene is neuroprotective in animal models and may attenuate cerebral vasospasm (cVSP) after aneurysmal subarachnoid hemorrhage (aSAH) in humans. We evaluated safety/tolerability and feasibility of intravenous dantrolene (IV-D) after aSAH.
Methods: In this single-center, randomized, double blind, placebo-controlled trial, 31 patients with acute aSAH were randomized to IV-D 1.25 mg IV every 6 hours x 7 days (n=16) or placebo (n=15). Primary endpoint was incidence of hyponatremia (sNa ≤ 134 mmol/L) and liver toxicity (% patients with ALT, AST and AlkPhos \u3e5x upper limit of normal). Secondary safety endpoints included tolerability, systemic hypotension and intracranial hypertension. Efficacy was explored by clinical, transcranial Doppler (TCD) or angiographic cVSP occurrence, delayed cerebral ischemia (DCI) and 3-month modified-Rankin-Scale, Glasgow Outcome Scale and Barthel Index. Statistical analysis was performed using non-parametric tests, generalized estimating equations and mixed models.
Results: Between IV-D vs. placebo, no differences were observed in the primary outcome (hyponatremia: 44% vs. 67% [p=0.29]; liver toxicity 6% vs. 0% [p=1.0]). Numerically more AEs and SAEs were seen in the IV-D group, but did not reach statistical significance (16 vs. 5 AEs, of which 5 vs. 2 were severe; RR 2.2; 95% CI 0.7-6.7; p=0.16). Three IV-D vs. two placebo patients reached stop criteria: one IV-D patient developed liver toxicity; two patients in each group developed brain edema requiring osmotherapy. No differences in angiographic, TCD, clinical cVSP, DCI, or 3-month functional outcomes were seen. Quantitative angiogram analysis revealed a trend towards increased vessel diameters in the IV-D group after the 7-day infusion-period (p=0.05).
Conclusions: In this small trial, IV-Dantrolene after aSAH was feasible, tolerable and safe, but was underpowered to show efficacy or outcome differences
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