Background: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that affects millions of people worldwide. The disease course varies greatly across individuals and many disease-modifying treatments with different safety and efficacy profiles have been developed recently. Prognostic models evaluated and shown to be valid in different settings have the potential to support people with MS and their physicians during the decision-making process for treatment or disease/life management, allow stratified and more precise interpretation of interventional trials, and provide insights into disease mechanisms.
View Article and Find Full Text PDFStudy Objective: Early post-operative delirium is a common perioperative complication in the post anesthesia care unit. To date it is unknown if a specific anesthetic regime can affect the incidence of delirium after surgery. Our objective was to examine the effect of volatile anesthetics on post-operative delirium.
View Article and Find Full Text PDFComputational reproducibility is a corner stone for sound and credible research. Especially in complex statistical analyses-such as the analysis of longitudinal data-reproducing results is far from simple, especially if no source code is available. In this work we aimed to reproduce analyses of longitudinal data of 11 articles published in PLOS ONE.
View Article and Find Full Text PDFResearch software has become a central asset in academic research. It optimizes existing and enables new research methods, implements and embeds research knowledge, and constitutes an essential research product in itself. Research software must be sustainable in order to understand, replicate, reproduce, and build upon existing research or conduct new research effectively.
View Article and Find Full Text PDFWe investigate the effect of the proportional hazards assumption on prognostic and predictive models of the survival time of patients suffering from amyotrophic lateral sclerosis. We theoretically compare the underlying model formulations of several variants of survival forests and implementations thereof, including random forests for survival, conditional inference forests, Ranger, and survival forests with splitting, with two novel variants, namely distributional and transformation survival forests. Theoretical considerations explain the low power of log-rank-based splitting in detecting patterns in non-proportional hazards situations in survival trees and corresponding forests.
View Article and Find Full Text PDFThe 'Treatment for Adolescents with Depression Study' (TADS, ClinicalTrials.gov, identifier: NCT00006286) was a cornerstone, randomized controlled trial evaluating the effectiveness of standard treatment options for major depression in adolescents. Whereas previous TADS analyses examined primarily effect modifications of treatment-placebo differences by various patient characteristics, less is known about the modification of inter-treatment differences, and hence, patient characteristics that might guide treatment selection.
View Article and Find Full Text PDFRandomized controlled trials (RCTs) usually enroll heterogeneous study population, and thus it is interesting to identify subgroups of patients for whom the treatment may be beneficial or harmful. A variety of methods have been developed to do such kind of post hoc analyses. Conventional generalized linear model is able to include prognostic variables as a main effect and predictive variables in an interaction with treatment variable.
View Article and Find Full Text PDFAn important task in early-phase drug development is to identify patients, which respond better or worse to an experimental treatment. While a variety of different subgroup identification methods have been developed for the situation of randomized clinical trials that study an experimental treatment and control, much less work has been done in the situation when patients are randomized to different dose groups. In this article, we propose new strategies to perform subgroup analyses in dose-finding trials and discuss the challenges, which arise in this new setting.
View Article and Find Full Text PDFStat Methods Med Res
October 2018
A treatment for a complicated disease might be helpful for some but not all patients, which makes predicting the treatment effect for new patients important yet challenging. Here we develop a method for predicting the treatment effect based on patient characteristics and use it for predicting the effect of the only drug (Riluzole) approved for treating amyotrophic lateral sclerosis. Our proposed method of model-based random forests detects similarities in the treatment effect among patients and on this basis computes personalised models for new patients.
View Article and Find Full Text PDFThe identification of patient subgroups with differential treatment effects is the first step towards individualised treatments. A current draft guideline by the EMA discusses potentials and problems in subgroup analyses and formulated challenges to the development of appropriate statistical procedures for the data-driven identification of patient subgroups. We introduce model-based recursive partitioning as a procedure for the automated detection of patient subgroups that are identifiable by predictive factors.
View Article and Find Full Text PDFIn Central Europe, protected areas are too small to ensure survival of populations of large carnivores. In the surrounding areas, these species are often persecuted due to competition with game hunters. Therefore, understanding how predation intensity varies spatio-temporally across areas with different levels of protection is fundamental.
View Article and Find Full Text PDFObjectives: To describe and comment on functionality and architecture of the software product Soarian developed by Siemens, to identify key differentiators to related products, and to comment on predecessor systems and beta versions. This has been done in the framework of a conference on health information systems of the IMIA.
Methods: Analyzing existing literature.
Stud Health Technol Inform
September 1999
The University of Erlangen-Nuremberg contains 22 hospitals and 11 autonomous medical departments which are spread out over a large area in the city of Erlangen. The necessary connections of these units and their computer based subsystems to each other and to the medical computer centre via fibre optics cables is complete. The internal cabling of the individual units is largely completed.
View Article and Find Full Text PDFElevated levels of the urokinase-type plasminogen activator (uPA) in tumor cells are conductive to tumor cell spread and metastasis. In a previous study we observed that suppression of RelA dramatically reduced endogenous uPA synthesis in the human ovarian cancer cell line OV-MZ-6. Because the uPA promoter contains three potential Rel-like protein binding motifs (RRBE, 5'-NF-kappaB, and 3'-NF-kappaB) we conducted the first thorough systematic uPA promoter analysis to examine the direct impact of Rel proteins on uPA gene transcription.
View Article and Find Full Text PDFIt is necessary to exchange information between the various institutions of the medical faculty of the University of Erlangen-Nurnberg. For example, basic patient data, which is collected in a central computer, must be distributed to various stations and laboratories. Also medical findings, which are already captured in computers in central laboratories, must be transmitted to various parts of the university hospitals.
View Article and Find Full Text PDFThe University of Erlangen-Nürnberg contains a large medical faculty with many hospitals, laboratories, and other departments distributed in the town of Erlangen, and it is necessary to exchange medical data between them. For example the basic patient data which are held on central computers, must be distributed to various stations and departments. In addition medical reports which are prepared on or generated by computers in central departments must be transmitted to various points in the hospitals [1].
View Article and Find Full Text PDFWe report the effect of pulmonary passage on random migration and chemokinesis of neutrophils through capillarylike pores under the in vitro condition of Boyden's test. Neutrophils were isolated either from the left ventricle or from the pulmonary artery of patients who underwent coronary angiography due to suspected angina pectoris or valvular heart disease. In all 14 cases left ventricle neutrophils showed significantly enhanced chemotactic-activated migration compared with pulmonary artery neutrophils.
View Article and Find Full Text PDFThe effects of atenolol, nifedipine, and their combination on gas exchange and exercise tolerance were studied in 27 patients with effort angina and normal global ventricular function in an open-label and randomized cross-over trial. Symptom-limited semi-supine exercise tests using a ramp protocol (20 W/min) with simultaneous breath-by-breath analysis of gas exchange were carried out after a 4-day wash-out period and after consecutive 2-week treatment periods with atenolol (50 mg b.i.
View Article and Find Full Text PDFProg Histochem Cytochem
December 1991
The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms).
View Article and Find Full Text PDFAn atypical presentation of purulent pericarditis caused by Staphylococcus aureus is described. A bacterial etiology was initially not taken into consideration because the clinical course was torpid and afebrile. Therefore, the appropriate treatment was delayed.
View Article and Find Full Text PDFIn about 30% of patients who were subjected to bone marrow transplantation, progressing interstitial and rarely obstructive pulmonary diseases can result in death. Early identification of curable diseases such as pulmonary changes during a "graft versus host reaction" would be desirable. Retrospective evaluation of 159 lung functions in 60 patients after bone marrow transplantation, however, revealed only moderate sensitivity of the peak flow value to vital capacity and FEV1, so that only pathological levels of this parameter will signify noticeable reductions in spirometric values.
View Article and Find Full Text PDFTo investigate the expectation of general insufficiency of osteoblasts with increasing age, we studied autotopsy material from 105 deceased persons of both sexes who had died between 16 and 91 years and in whom clinically manifest diseases of the bone had been excluded. Quantitative morphometric examination of the structure of the spongy bone of the 3rd-5th lumbar vertebral bodies (LVBs) and of the 5th-7th cervical vertebral bodies (CVBs) was carried out in frontal and sagittal planes, the parameters analysed being volumetric density (Vv), surface density (Sv) and specific surface area (S/V), and the results were subjected to statistical evaluation. The results showed that in the three LVBs, Vv, Sv and S/V behave in a similar manner, Vv and Sv decreasing after the age of 50 years by more than one-third while S/V remains constant throughout life.
View Article and Find Full Text PDFTo investigate the question as to a possible insufficiency of the osteoblasts with increasing age, autopsy material obtained from 105 deceased of both sexes at an age of 16 to 91 in whom clinically manifest bone diseases had been excluded, was studied. The structure of the spongy bone of the 3rd to 5th lumbar vertebral bodies (LVB) and of the 5th to 7th cervical vertebral bodies (CVB) was examined quantitatively-morphometrically, and the results were submitted to a statistical evaluation. In the three LVB, Vv, Sv and S/V behave in a similar manner.
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