Erasmus University Medical Center

About: Erasmus University Medical Center is a healthcare organization based out in Rotterdam, Zuid-Holland, Netherlands. It is known for research contribution in the topics: Population & Medicine. The organization has 8162 authors who have published 11395 publications receiving 517117 citations.

Biology of the peritoneum in normal homeostasis and after surgical trauma.

Abstract: The peritoneum is a serous membrane, which has a protective function for the contents of the abdominal cavity. It maintains homeostasis by allowing exchange of molecules and production of peritoneal fluid, thus providing an environment in which intra-abdominal organs can function properly. When traumatized, whether by surgery or due to inflammatory processes, a series of responses come into action to regenerate the injured part of the peritoneum. The inflammatory reaction causes influx of inflammatory cells but also activates resident mesothelial cells, ultimately leading to a fibrinous exudate. Depending on the severity of the trauma this exudate is transient due to fibrinolysis, or becomes more dense as a result of fibroblasts persisting, leading to fibrinous adhesions. A pivotal role is taken by the enzyme plasmin and its promotors and inhibitors; it is mainly the tissue-type plasminogen activator/plasminogen activator inhibitor ratio which determines the rate of fibrinolysis and therefore the rate of adhesion formation. The rate of injury determines the rate and extent of the inflammatory response to that injury; in its turn the inflammatory reaction determines the extent of adhesion formation. One should realize this when performing intra-abdominal surgery, which is in fact operating inside the peritoneal organ.

Genomic and geographic distribution of SNP-defined runs of homozygosity in Europeans

Abstract: The availability of high-density panels of genetic polymorphisms has led to the discovery of extended regions of apparent autozygosity in the human genome. At the genotype level, these regions present as sizeable stretches, or 'runs', of homozygosity (ROH). Here, we investigated both the genomic and the geographic distribution of ROHs in a large European sample of individuals originating from 23 subpopulations. The genomic ROH distribution was found to be characterized by a pattern of highly significant non-uniformity that was virtually identical in all subpopulations studied. Some 77 chromosomal regions contained ROHs at considerable frequency, thereby forming 'ROH islands' that were not explicable by high linkage disequilibrium alone. At the geographic level, the number and cumulative length of ROHs followed a prominent South to North gradient in agreement with expectations from European population history. The individual ROH length, in contrast, showed only minor and unsystematic geographic variation. While our findings are thus consistent with a larger effective population size in Southern than in Northern Europe, combined with a higher historic population density and mobility, they also indicate that the patterns of meiotic recombination in humans must have been very similar throughout the continent. Extending previous reports of a strong correlation between geography and identity-by-state, our data show that the genomic identity-by-descent patterns of Europeans are also clinal. As a consequence, the planning, design and interpretation of ROH-based genetic studies must take sample origin into account in order for such studies to be sensible and valid.

Integrating quantitative and qualitative methods in patient care information system evaluation: guidance for the organizational decision maker.

Abstract: Objective: The aim of this paper is twofold. First, we describe two important dimensions of patient care information systems (PCIS) evaluation: the domain of evaluation and the different phases of the PCIS implementation. Second, we claim that, though Randomized Controlled Trials (RCTs) are often still seen as the standard approach, this type of design hardly generates relevant information for the organizational decision maker. Method: Interpretive study of evaluation literature. Results and Conclusions: The field of evaluation is scattered and the types of questions that can be asked and methods that can be used seem infinite and badly demarcated. Different stakeholders, moreover, often have different priorities in evaluating ICT. The most important reason for the lack of relevance of RCTs is that they are ill suited for investigating why and how a PCIS is being used, or not, and what the (often unplanned) effects and consequences are. Subsequently, our aim is to contribute to the discussion about the viability of qualitative versus quantitative methods in PCIS evaluation, by arguing for a specific integration of quantitative and qualitative research methods. The joint utilization of these methods, we claim, yields the richest results.