University of Düsseldorf

About: University of Düsseldorf is a education organization based out in Düsseldorf, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 25225 authors who have published 49155 publications receiving 1946434 citations.

Seriousness checks are useful to improve data validity in online research.

Abstract: Nonserious answering behavior increases noise and reduces experimental power; it is therefore one of the most important threats to the validity of online research. A simple way to address the problem is to ask respondents about the seriousness of their participation and to exclude self-declared nonserious participants from analysis. To validate this approach, a survey was conducted in the week prior to the German 2009 federal election to the Bundestag. Serious participants answered a number of attitudinal and behavioral questions in a more consistent and predictively valid manner than did nonserious participants. We therefore recommend routinely employing seriousness checks in online surveys to improve data validity.

The effect of long-term glucocorticoid therapy on pituitary-adrenal responses to exogenous corticotropin-releasing hormone.

Abstract: Background. Suppression of pituitary--adrenal function is a well-known consequence of glucocorticoid therapy, manifested principally by decreased corticotropin secretion. To determine the degree of suppression of pituitary—adrenal function in patients treated with different doses of synthetic glucocorticoid medication for different periods, we measured the pituitary—adrenal response to the administration of exogenous human corticotropin-releasing hormone (CRH). Methods. We studied 279 patients who were receiving daily therapy with 5 to 30 mg of prednisone or its equivalent to treat various chronic diseases, principally collagen vascular disorders, and 50 normal subjects. Therapy ranged in duration from 1 week to 15 years. Stimulation tests using 100 μg of CRH as a bolus injection were performed in the morning, 24 hours after the most recent dose of glucocorticoids. In 61 patients an insulin hypoglycemia test, thought by many to be the reference standard, was also performed to assess the reliabili...

cIMPACT-NOW update 6: new entity and diagnostic principle recommendations of the cIMPACT-Utrecht meeting on future CNS tumor classification and grading.

Abstract: cIMPACT-NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy) was established to evaluate and make practical recommendations on recent advances in the field of CNS tumor classification, particularly in light of the rapid progress in molecular insights into these neoplasms. For Round 2 of its deliberations, cIMPACT-NOW Working Committee 3 was reconstituted and convened in Utrecht, The Netherlands, for a meeting designed to review putative new CNS tumor types in advance of any future World Health Organization meeting on CNS tumor classification. In preparatory activities for the meeting and at the actual meeting, a list of possible entities was assembled and each type and subtype debated. Working Committee 3 recommended that a substantial number of newly recognized types and subtypes should be considered for inclusion in future CNS tumor classifications. In addition, the group endorsed a number of principles-relating to classification categories, approaches to classification, nomenclature, and grading-that the group hopes will also inform the future classification of CNS neoplasms.

Relationships between plasma measures of oxidative stress and metabolic control in NIDDM.

Abstract: Diabetes mellitus may be associated with increased lipid peroxidation which may contribute to long-term tissue damage. To test this hypothesis, we measured hydroperoxides (ROOHs) as well as α-tocopherol in plasma from healthy subjects and individuals with non-insulin-dependent diabetes mellitus (NIDDM) (n = 41 and 87, respectively). ROOHs were analysed using the ferrous oxidation with xylenol orange version II (FOX2) assay in conjunction with a specific ROOH reductant, triphenylphosphine. α-Tocopherol was analysed by HPLC with fluorimetric detection. NIDDM patients had lower cholesterol standardised α-tocopherol levels as compared to control subjects (3.3 ± 1.0 vs 5.1 ± 2.3 (μmol/l)/(mmol/l); p < 0.0005, Mann-Whitney test): range (1.5–6.5 vs 1.9–13.0, respectively). Plasma ROOHs were substantially higher in the diabetic subjects compared to those of the control subjects (9.4 ± 3.3 vs 4.1 ± 2.2 μmol/l; p < 0.0005 Mann-Whitney test: range 2.7–16.8 vs 0.4–10.3, respectively). ROOH/cholesterol standardised α-tocopherol ratio was significantly higher in the diabetic patients compared to control subjects (3.2 ± 1.6 vs 0.9 ± 0.6; p < 0.0005, Mann-Whitney test: range 0.7–8.3 and 0.1–2.7, respectively). Plasma levels of ROOHs and α-tocopherol were similar in diabetic patients with or without complications as well as in smokers and non-smokers. The present study confirms previous findings from this laboratory that NIDDM is associated with increased oxidative stress as assessed by plasma ROOHs. Increased oxidative stress in diabetic patients appears to be related to the underlying metabolic abnormalities in diabetes, rather than to the complications of this disease. We therefore suggest that oxidative stress is an early stage in the disease pathology, which may contribute to the development of complications. [Diabetologia (1997) 40: 647–653]