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Jerin C.,Ludwig Maximilians University of Munich | Wakili R.,Ludwig Maximilians University of Munich | Kalla R.,Inselspital Bern | Gurkov R.,Ludwig Maximilians University of Munich
Ear and Hearing | Year: 2015

Objective: Ocular vestibular-evoked myogenic potentials (oVEMPs) represent extraocular muscle activity in response to vestibular stimulation. The authors sought to investigate whether posture-induced increase of the intracranial pressure (ICP) modulated oVEMP frequency tuning, that is, the amplitude ratio between 500-Hz and 1000-Hz stimuli. Design: Ten healthy subjects were enrolled in this study. The subjects were positioned in the horizontal plane (0 degree) and in a 30-degree head-downwards position to elevate the ICP. In both positions, oVEMPs were recorded using 500-Hz and 1000-Hz air-conducted tone bursts. Results: When tilting the subject from the horizontal plane to the 30-degree head-down position, oVEMP amplitudes in response to 500-Hz tone bursts distinctly decreased (3.40 μV versus 2.06 μV; p < 0.001), whereas amplitudes to 1000 Hz were only slightly diminished (2.74 μV versus 2.48 μV; p = 0.251). Correspondingly, the 500/1000-Hz amplitude ratio significantly decreased when tilting the subjects from 0-to 30-degree inclination (1.59 versus 1.05; p = 0.029). Latencies were not modulated by head-down position. Conclusions: Increasing ICP systematically alters oVEMPs in terms of absolute amplitudes and frequency tuning characteristics. oVEMPs are therefore in principle suited for noninvasive ICP monitoring. © 2015 Wolters Kluwer Health, Inc. All rights reserved • Printed in the U.S.A.

Bogni S.,University of Bern | Stumpp O.,University of Bern | Reinert M.,Inselspital Bern | Frenz M.,University of Bern
Journal of Biophotonics | Year: 2010

Laser tissue soldering (LTS) is a promising technique for tissue fusion based on a heat-denaturation process of proteins. Thermal damage of the fused tissue during the laser procedure has always been an important and challenging problem. Particularly in LTS of arterial blood vessels strong heating of the endothelium should be avoided to minimize the risk of thrombosis. A precise knowledge of the temperature distribution within the vessel wall during laser irradiation is inevitable. The authors developed a finite element model (FEM) to simulate the temperature distribution within blood vessels during LTS. Temperature measurements were used to verify and calibrate the model. Different parameters such as laser power, solder absorption coefficient, thickness of the solder layer, cooling of the vessel and continuous vs. pulsed energy deposition were tested to elucidate their impact on the temperature distribution within the soldering joint in order to reduce the amount of further animal experiments. A pulsed irradiation with high laser power and high absorbing solder yields the best results. © 2010 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Guth U.,University of Basel | Guth U.,Breast Center Senosuisse | Myrick M.E.,Inselspital Bern | Kandler C.,CHW | Vetter M.,University of Basel
Breast | Year: 2013

In order to report specifically on the use of adjuvant endocrine therapy (ET) in the oldest old breast cancer (BC) patients, we compared treatment patterns including drug compliance and persistence in a cohort of patients who were ≥80 years at diagnosis ( n=79) with those of "younger elderly" patients who were 60-79 years old ( n=358). The geriatric cohort more commonly declined the recommended ET (non-compliance: 13.0% vs. 4.5%, p=0.011). Of the patients who initiated ET, only a minority of the older patients completed the planned therapy duration of five years (39.6% vs. 71.3%, p<0.001). However, when applying strict criteria for non-persistence, this was found in comparable frequency (17.0% vs. 12.0%, p=0.370). In older patients, medication was more often discontinued by the physician due to serious medical reasons independent of BC (17.0% vs. 4.7%, p=0.003). Older women were treated by a general practitioner more often and not by an oncologist (54.4% vs. 23.9%, p<0.001). Studies on compliance/persistence on cancer therapy in the oldest old demand a detailed follow-up of the patients and the consideration of principles of geriatric medicine. Efforts should be made to make sure that all physicians, but above all general practitioners, who are predominantly involved in the treatment of elderly BC patients, are provided with current knowledge and skills, as to ensure optimal patient management. © 2013 Elsevier Ltd.

Toteberg-Harms M.,University of Zurich | Sturm V.,University of Zurich | Knecht P.B.,University of Zurich | Funk J.,University of Zurich | Menke M.N.,Inselspital Bern
Graefe's Archive for Clinical and Experimental Ophthalmology | Year: 2012

Background The aim of this work is to assess the repeatability of spectral-domain-OCT (SD-OCT) retinal nerve fiber layer thickness (RNFL) thickness measurements in a non-glaucoma group and patients with glaucoma and to compare these results to conventional time-domain-OCT (TD-OCT). Methods In a prospective, comparative, observational casecontrol study, 50 eyes of 25 non-glaucoma and 22 eyes of 11 patients with primary open angle glaucoma (POAG) were included. SD-OCT and TD-OCT circle scans were centered on the optic disc. In each eye, OCT scans were performed three times by two independent observers. RNFL thickness was measured in four quadrants around the optic disc. In addition, the overall mean RNFL thickness was assessed. Intraclass correlation coefficients (ICC) and coefficients of variation (COV) were calculated. Inter-observer and inter-OCT repeatability was visualized by using Bland-Altman analysis. Results Intra-observer repeatability for TD- OCT was good with an ICC mean RNFL thickness of 0.939 in non-glaucomas and 0.980 in glaucomatous eyes. For SD-OCT, intraobserver repeatability was higher with an ICC of 0.989 for non-glaucomas and 0.997 for glaucomatous eyes. COVs for TD-OCT ranged from 2.9-7.7% in non-glaucomas and from 6.0-13.3% in glaucoma patients. COVs for SD-OCT ranged from 0.3-1% in non-glaucomas and from 0.9-2.3% in glaucomatous eyes. COVs were influenced by various factors. In the glaucoma group, COVs were significantly higher (p<0.001) compared to the non-glaucoma group. COVs increased by a mean of 5.1% when TD-OCT was used instead of SD-OCT (p<0.001). Conclusions SD-OCT RNFL thickness measurements in healthy volunteers and glaucoma patients showed good intra- and inter-observer repeatability. Especially in glaucomatous eyes, repeatability of SD-OCT was superior to TD-OCT. © Springer-Verlag 2011.

Masselli G.,University of Rome La Sapienza | Derchi L.,University of Genoa | McHugo J.,Birmingham Womens Hospital | Rockall A.,Imperial College London | And 3 more authors.
European Radiology | Year: 2013

Acute abdominal pain in pregnancy presents diagnostic and therapeutic challenges. Standard imaging techniques need to be adapted to reduce harm to the fetus from X-rays due to their teratogenic and carcinogenic potential. Ultrasound remains the primary imaging investigation of the pregnant abdomen. Magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of gynaecological and obstetric problems during pregnancy and in the setting of acute abdomen during pregnancy. MRI overcomes some of the limitations of ultrasound, mainly the size of the gravid uterus. MRI poses theoretical risks to the fetus and care must be taken to minimise these with the avoidance of contrast agents. This article reviews the evolving imaging and clinical literature on appropriate investigation of acute abdominal and pelvic pain during established intrauterine pregnancy, addressing its common causes. Guidelines based on the current literature and on the accumulated clinico-radiological experience of the European Society of Urogenital Radiology (ESUR) working group are proposed for imaging these suspected conditions. Key Points • Ultrasound and MRI are the preferred investigations for abdominal pain during pregnancy. • Ultrasound remains the primary imaging investigation because of availability and portability. • MRI helps differentiate causes of abdominopelvic pain when ultrasound is inconclusive. • If MRI cannot be performed, low-dose CT may be necessary. • Following severe trauma, CT cannot be delayed because of radiation concerns. © 2013 European Society of Radiology.

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