Erasmus Medical College

Rotterdam, Netherlands

Erasmus Medical College

Rotterdam, Netherlands

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Lemmens N.,Erasmus Medical College | van Wamel W.,Erasmus Medical College | Snijders S.,Erasmus Medical College | Lesse A.J.,State University of New York at Buffalo | And 4 more authors.
Microbial Pathogenesis | Year: 2011

USA300 Staphylococcus aureus is responsible for the current outbreak of skin abscesses in the United States. Unlike other USA types, USA300 colonizes the rectum at rates higher than the nose. The reason for the difference in colonization site preference may be related to specific adherence or attachment factors contained in the genome of these strains. Additional knowledge in this field may help design novel prophylactic and therapeutic strategies to combat staphylococcal infections. Strains of USA300 MSSA and MRSA colonizing the nose and/or rectum from children with staphylococcal skin abscesses were compared by whole genome array technology to identify bacterial genetic determinants associated with site-specific colonization. Strains isolated from different colonization sites were indistinguishable by genomic content. Site-specific colonization traits were not detected in the colonizing bacteria by this array. Either host characteristics associated with staphylococcal carriage or under represented bacterial genomic constructions need to be examined to determine the etiology of this site-specific colonization. © 2010 Elsevier Ltd.


Gorson K.C.,Tufts University | Van Schaik I.N.,University of Amsterdam | Merkies I.S.J.,Maastricht University | Merkies I.S.J.,Spaarne Hospital | And 12 more authors.
Journal of the Peripheral Nervous System | Year: 2010

Defining long-term outcomes in chronic inflammatory demyelinating polyneuropathy (CIDP) has been complicated by varying definitions of treatment response and differing scales measuring impairment or disability. An expert panel was convened to devise a CIDP Disease Activity Status (CDAS) and to classify long-term outcome by applying it to 106 patients with a consensus diagnosis of CIDP. Sixty of these cases were graded blindly by three independent reviewers to assess inter-rater reliability. The mean duration of follow-up was 6.4 years (range, 3 months-23 years). Eleven percent of patients were classified as cured (stable examination and off treatment for ≥5 years), 20% were in remission (stable and off treatment for <5 years), 44% had stable active disease but required ongoing therapy for at least 1 year, 7% were improving after recent initiation of therapy, and 18% had unstable active disease (treatment naïve or treatment refractory). Excellent inter-rater reliability was observed (kappa scores: 0.93-0.97; p < 0.0001). The CDAS is considered a simple and reproducible tool to classify patients with CIDP according to disease activity and treatment status that can be applied easily in practice and potentially to select patients for clinical trials. © 2010 Peripheral Nerve Society.


Westendorff S.,German Primate Center | Westendorff S.,Bernstein Center for Computational Neuroscience | Kuang S.,German Primate Center | Taghizadeh B.,German Primate Center | And 4 more authors.
Journal of Neurophysiology | Year: 2015

Different error signals can induce sensorimotor adaptation during visually guided reaching, possibly evoking different neural adaptation mechanisms. Here we investigate reach adaptation induced by visual target errors without perturbing the actual or sensed hand position. We analyzed the spatial generalization of adaptation to target error to compare it with other known generalization patterns and simulated our results with a neural network model trained to minimize target error independent of prediction errors. Subjects reached to different peripheral visual targets and had to adapt to a sudden fixed-amplitude displacement ("jump") consistently occurring for only one of the reach targets. Subjects simultaneously had to perform contralateral unperturbed saccades, which rendered the reach target jump unnoticeable. As a result, subjects adapted by gradually decreasing reach errors and showed negative aftereffects for the perturbed reach target. Reach errors generalized to unperturbed targets according to a translational rather than rotational generalization pattern, but locally, not globally. More importantly, reach errors generalized asymmetrically with a skewed generalization function in the direction of the target jump. Our neural network model reproduced the skewed generalization after adaptation to target jump without having been explicitly trained to produce a specific generalization pattern. Our combined psychophysical and simulation results suggest that target jump adaptation in reaching can be explained by gradual updating of spatial motor goal representations in sensorimotor association networks, independent of learning induced by a prediction-error about the hand position. The simulations make testable predictions about the underlying changes in the tuning of sensorimotor neurons during target jump adaptation. © 2015 the American Physiological Society.


van Alphen B.,Erasmus Medical College | Winkelman B.H.J.,Erasmus Medical College | Frens M.A.,Erasmus Medical College
Investigative Ophthalmology and Visual Science | Year: 2010

PURPOSE. To study three-dimensional optokinetic eye movements of wild-type C57BL/6J mice, the most commonly used mouse in oculomotor physiology. Optokinetic eye movements are reflexive eye movements that use visual feedback to minimize image motion across the retina. These gaze-stabilizing reflexes are a prominent model system for studying motor control and learning. They are three dimensional and consist of a horizontal, vertical, and torsional component. METHODS. Eye movements were evoked by sinusoidally rotating a virtual sphere of equally spaced dots at six frequencies (0.1-1 Hz), with a fixed amplitude of 5°. Markers were applied to the mouse eye and video oculography was used to record its movements in three dimensions. In addition, marker tracking was compared with conventional pupil tracking of horizontal optokinetic eye movements. RESULTS. Gains recorded with marker and pupil tracking are not significantly different. Optokinetic eye movements in mice are equally well developed in all directions and have a uniform input- output relation for all stimuli, including stimuli that evoke purely torsional eye movements, with gains close to unity and minimal phase differences. CONCLUSIONS. Optokinetic eye movements of C57Bl6 mice largely compensate for image motion over the retina, regardless of stimulus orientation. All responses are frequency-velocity dependent: gains decrease and phase lags increase with increasing stimulus frequency. Mice show strong torsional responses, with high gains at low stimulus frequency. © Association for Research in Vision and Ophthalmology.


PubMed | Erasmus Medical College
Type: Journal Article | Journal: Investigative ophthalmology & visual science | Year: 2010

To study three-dimensional optokinetic eye movements of wild-type C57BL/6J mice, the most commonly used mouse in oculomotor physiology. Optokinetic eye movements are reflexive eye movements that use visual feedback to minimize image motion across the retina. These gaze-stabilizing reflexes are a prominent model system for studying motor control and learning. They are three dimensional and consist of a horizontal, vertical, and torsional component.Eye movements were evoked by sinusoidally rotating a virtual sphere of equally spaced dots at six frequencies (0.1-1 Hz), with a fixed amplitude of 5 degrees . Markers were applied to the mouse eye and video oculography was used to record its movements in three dimensions. In addition, marker tracking was compared with conventional pupil tracking of horizontal optokinetic eye movements.Gains recorded with marker and pupil tracking are not significantly different. Optokinetic eye movements in mice are equally well developed in all directions and have a uniform input-output relation for all stimuli, including stimuli that evoke purely torsional eye movements, with gains close to unity and minimal phase differences.Optokinetic eye movements of C57Bl6 mice largely compensate for image motion over the retina, regardless of stimulus orientation. All responses are frequency-velocity dependent: gains decrease and phase lags increase with increasing stimulus frequency. Mice show strong torsional responses, with high gains at low stimulus frequency.


PubMed | Erasmus Medical College
Type: Journal Article | Journal: Journal of clinical oncology : official journal of the American Society of Clinical Oncology | Year: 2016

1508 Background: Early lung cancer detection with X-ray was unable to reduce lung cancer mortality. Low-dose spiral CT screening cohort studies have demonstrated that lung cancer can be detected at an early stage in a high percentage. Unknown is whether spiral CT screening will lead to a lung cancer mortality reduction and if lung cancer screening will be cost-effective. These questions will be addressed in the randomized Dutch-Belgian-Danish lung cancer screening trial (NELSON) of 20,000 participants.To identify high-risk subjects a health questionnaire was sent to 600,000 men and women aged 50-74 in seven Dutch public health districts and 14 municipalities in Belgium. Current and former smokers (quit < 10 years) who smoked at least 16 cigarettes a day for at least 26 years or at least 11 cigarettes a day for at least 31 years were invited. After receiving informed consent, participants were randomized between screen-arm and control-arm (usual care). CT scans are performed with 16-detector multi-slice Spiral CT scanners and Siemens Lungcare workstations and software for volumetric analyses in all 4 screening sites. The Lungcare radiological data are automatically uploaded in the NELSON Management System (NMS).In the Netherlands and Belgium, 15,822 subjects have been randomized (1:1) and have undergone baseline and 2nd round sceening one year later. Of them, 83% was male and 17% female, 56% current smoker and 44% former smoker. The majority of current (n=1558) and former (n=1355) smokers had a smoking history of 30-39 PY. Of the former smokers, 62% had quit < 6 yrs and 36% between 6-10 yrs. In total 13,081 nodules have been detected at baseline. Of them, 66% were benign or < 50 mm


PubMed | Erasmus Medical College
Type: Comparative Study | Journal: Microbial pathogenesis | Year: 2011

USA300 Staphylococcus aureus is responsible for the current outbreak of skin abscesses in the United States. Unlike other USA types, USA300 colonizes the rectum at rates higher than the nose. The reason for the difference in colonization site preference may be related to specific adherence or attachment factors contained in the genome of these strains. Additional knowledge in this field may help design novel prophylactic and therapeutic strategies to combat staphylococcal infections. Strains of USA300 MSSA and MRSA colonizing the nose and/or rectum from children with staphylococcal skin abscesses were compared by whole genome array technology to identify bacterial genetic determinants associated with site-specific colonization. Strains isolated from different colonization sites were indistinguishable by genomic content. Site-specific colonization traits were not detected in the colonizing bacteria by this array. Either host characteristics associated with staphylococcal carriage or under represented bacterial genomic constructions need to be examined to determine the etiology of this site-specific colonization.

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