65 research outputs found

    Antibiotic-Impregnated Versus Silver-Bearing External Ventricular Drainage Catheters: Preliminary Results in a Randomized Controlled Trial

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    Background: Evaluation of antibiotic-impregnated (AI) and ionized silver particle coated external ventricular drainage catheters (EVD) in patients with subarachnoid (SAH) or intracranial hemorrhage (ICH). Methods: Between February 2011 and June 2012, 40 patients with acute hydrocephalus due to SAH, ICH or intraventricular hemorrhage were enrolled in a prospective, randomized, mono-center pilot study. Primary endpoints were defined as: number of events of cerebrospinal fluid (CSF) infections. Secondary endpoints were defined as: neurosurgical complications following the placement of the EVD, number of revisions of EVD catheters, and cost effectiveness. Results: Sixty-one EVD placements in 40 patients, 32 antibiotic-coated (Bactiseal®), 29 silver-bearing catheters (VentriGuard®), have been performed. Confirmed or high suspicion of CSF infections occurred in 11 out of 61 events (confirmed infection: p=0.71, probable infection: p=0.90). Revisions of EVD were needed in 13 cases (22%) due to CSF infection, dysfunction, impaired healing, or malplacement (p=0.37). Conclusion: Regarding CSF infection rate and dysfunction, no statistical significant differences between the two EVD catheters Bactiseal® versus VentriGuard® were found. The silver-bearing catheter might offer a safe and cost-conscious alternative to the AI cathete

    Impact of intraoperative MRI-guided transsphenoidal surgery on endocrine function and hormone substitution therapy in patients with pituitary adenoma

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    BACKGROUND: Pituitary adenomas are rare with an incidence of 0.4-8.2 per 105 inhabitants. Symptoms range from headaches to pituitary insufficiency or excessive output of hormones with associated disease. Except for prolactinomas, surgery is recommended as the first line and most effective treatment for the majority of these tumours. One of the refinements of surgical therapy introduced was intraoperative magnetic resonance imaging (iMRI). OBJECTIVE: The aim of this study was to analyse the postoperative pituitary function and the general outcome of patients treated for non-functioning and GH-producing pituitary adenomas with a transsphenoidal iMRI-assisted approach using the PoleStar™ N20 imager. METHODS: A total of 148 consecutive iMRI-guided surgeries for GH-producing and non-functioning pituitary adenomas were retrospectively analysed. Patients' clinical data, endocrinological parameters, clinical examinations and pre-/post- and intraoperative imaging studies were evaluated. RESULTS: A total of 101 patients could be classified as being in remission at follow-up; 26 (17.6%) of them due to iMRI allowing additional tumour removal. A total of 44 patients (29.7%) had more complete tumour removal because remnants were detected by iMRI. The mean hormone levels of patients did not differ significantly between pre- and postoperative examinations. There were 62 patients with preoperative, and 43 patients with postoperative pituitary insufficiency, thus, due to surgery there were 19 (12.8%) patients with improved pituitary function. CONCLUSIONS: The results show this method to be a safe and effective treatment option increasing remission rate and keeping complication rate low. Postoperative pituitary function was preserved or improved - possibly due to more exact iMRI-assisted tumour removal

    Слобожанщина: літературний вимір

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    To determine diurnal variations in the physical and biological state of Lake Garda in early spring, high-resolution measurements were made of the vertical distribution of temperature and fluorescence in the upper 100 meters during 5–7 March 2014. In this paper, the results of these measurements are presented and a preliminary analysis that focuses on the connection between the vertical mixing coefficient K<sub>T</sub> and the chlorophyll-a (chl-a) concentration is given. From these first direct measurements of turbulence-related quantities in Lake Garda, it is found that mixed-layer values of K<sub>T </sub>decrease, while surface chl-a concentrations increase, over the day. Variations in K<sub>T </sub>can be connected to the changes in the surface wind stress, while variations in chl-a are negatively correlated with the amplitude of K<sub>T</sub>. In addition, satellite observations of the surface chl-a concentration are analysed to test their use for the calibration of the fluorescence measurements and also for their potential utility in remotely determining vertical mixing in the upper layers of the lake

    Thermal production of ultrarelativistic right-handed neutrinos: Complete leading-order results

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    The thermal production of relativistic right-handed Majorana neutrinos is of importance for models of thermal leptogenesis in the early Universe. Right-handed neutrinos can be produced both by 1 2 decay or inverse decay and by 2 -> 2 scattering processes. In a previous publication, we have studied the production via 1 2 (inverse) decay processes. There we have shown that multiple scattering mediated by soft gauge boson exchange also contributes to the production rate at leading order, and gives a strong enhancement. Here we complete the leading order calculation by adding 2 -> 2 scattering processes involving either electroweak gauge bosons or third-generation quarks. We find that processes with gauge interactions give the most important contributions. We also obtain a new sum rule for the Hard Thermal Loop resummed fermion propagator.Comment: 27 pages, 7 figures. Error in the matrix element for the (subdominant) subprocess with s-channel fermion exchange corrected. This changes the corresponding phase space integral and the constant c_V. Numerically it increases the total 2 -> 2 rate by about 2 percent and the complete rate by about 1 percent. The main results and conclusions are unaffecte

    Leptogenesis from Soft Supersymmetry Breaking (Soft Leptogenesis)

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    Soft leptogenesis is a scenario in which the cosmic baryon asymmetry is produced from a lepton asymmetry generated in the decays of heavy sneutrinos (the partners of the singlet neutrinos of the seesaw) and where the relevant sources of CP violation are the complex phases of soft supersymmetry-breaking terms. We explain the motivations for soft leptogenesis, and review its basic ingredients: the different CP-violating contributions, the crucial role played by thermal corrections, and the enhancement of the efficiency from lepton flavour effects. We also discuss the high temperature regime T>107T > 10^7 GeV in which the cosmic baryon asymmetry originates from an initial asymmetry of an anomalous RR-charge, and soft leptogenesis reembodies in RR-genesis.Comment: References updated. Some minor corrections to match the published versio

    Examining leptogenesis with lepton flavor violation and the dark matter abundance

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    Within a supersymmetric (SUSY) type-I seesaw framework with flavor-blind universal boundary conditions, we study the consequences of requiring that the observed baryon asymmetry of the Universe be explained by either thermal or non-thermal leptogenesis. In the former case, we find that the parameter space is very constrained. In the bulk and stop-coannihilation regions of mSUGRA parameter space (that are consistent with the measured dark matter abundance), lepton flavor-violating (LFV) processes are accessible at MEG and future experiments. However, the very high reheat temperature of the Universe needed after inflation (of about 10^{12} GeV) leads to a severe gravitino problem, which disfavors either thermal leptogenesis or neutralino dark matter. Non-thermal leptogenesis in the preheating phase from SUSY flat directions relaxes the gravitino problem by lowering the required reheat temperature. The baryon asymmetry can then be explained while preserving neutralino dark matter, and for the bulk or stop-coannihilation regions LFV processes should be observed in current or future experiments.Comment: 20 pages, 5 figures, 1 tabl

    A semi-automated software program to assess the impact of second reads in prostate MRI for equivocal lesions: results from a UK tertiary referral centre

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    Purpose: To investigate the utility of a prostate magnetic resonance imaging (MRI) second read using a semi-automated software program in the one-stop clinic, where patients undergo multiparametric MRI, review and biopsy planning in one visit. We looked at concordance between readers for patients with equivocal scans and the possibility for biopsy deferral in this group. Methods: We present data from 664 consecutive patients. Scans were reported by seven different expert genitourinary radiologists using dedicated software (MIM®) and a Likert scale. All scans were rescored by another expert genitourinary radiologist using a customised workflow for second reads that includes annotated biopsy contours for accurate visual targeting. The number of scans in which a biopsy could have been deferred using biopsy results and prostate specific antigen density was assessed. Gleason score ≥ 3 + 4 was considered clinically significant disease. Concordance between first and second reads for equivocal scans (Likert 3) was evaluated. Results: A total of 209/664 (31%) patients scored Likert 3 on first read, 128 of which (61%) were concordant after second read. 103/209 (49%) of patients with Likert 3 scans were biopsied, with clinically significant disease in 31 (30%) cases. Considering Likert 3 scans that were both downgraded and biopsied using the workflow-generated biopsy contours, 25/103 (24%) biopsies could have been deferred. Conclusions: Implementing a semi-automated workflow for accurate lesion contouring and targeting biopsies is helpful during the one-stop clinic. We observed a reduction of indeterminate scans after second reading and almost a quarter of biopsies could have been deferred, reducing the potential biopsy-related side effects

    Second surgery for progressive glioblastoma: a multi‐centre questionnaire and cohort‐based review of clinical decision‐making and patient outcomes in current practice

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    PURPOSE: Glioblastoma prognosis is poor. Treatment options are limited at progression. Surgery may benefit, but no quality guidelines exist to inform patient selection. We sought to describe variations in surgical management at progression, highlight where further evidence is needed, and build towards a consensus strategy. METHODS: Current practice in selection of patients with progressive GBM for second surgery was surveyed online amongst specialists in the UK and Europe. We complemented this with an assessment of practice in a retrospective cohort study from six United Kingdom neurosurgical units. We used descriptive statistics to analyse the data. RESULTS: 234 questionnaire responses were received. Maintaining or improving patient quality of life was key to decision making, with variation as to whether patient age, performance status or intended extent of resection was relevant. MGMT methylation status was not important. Half considered no minimum time after first surgery. 288 patients were reported in the cohort analysis. Median time to second surgery from first surgery 390 days. Median overall survival 815 days, with no association between time to second surgery and time to death (p = 0.874). CONCLUSIONS: This is the most wide-ranging examination of contemporaneous practice in management of GBM progression. Without evidence-based guidelines, the variation is unsurprising. We propose consensus guidelines for consideration, to reduce heterogeneity in decision making, support data collection and analysis of factors influencing outcomes, and to inform clinical trials to establish whether second surgery improves patient outcomes, or simply selects to patients already performing well
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