De toepasbaarheid van de amoebe-benadering op terrestrische ecosystemen

VakpublicatieInstitute of Environmental Science

Recombinant human activated protein C in the treatment of acute respiratory distress syndrome

Rationale: Pulmonary coagulopathy may play a pathogenetic role in acute respiratory distress syndrome (ARDS), by contributing to alveolocapillary inflammation and increased permeability. Recombinant human activated protein C (rh-APC) may inhibit this process and thereby improve patient outcome. Methods: A prospective randomized, saline-controlled, single-blinded clinical trial was performed in the intensive care units of two university hospitals, and patients with ARDS were included within 24 h after meeting inclusion criteria. Intervention: A 4-day course of intravenous rh-APC (24 mcg/kg/h) (n = 33) versus saline (n = 38). Outcomes: The primary outcome parameter was the pulmonary leak index (PLI) of 67Gallium-transferrin as a measure of alveolocapillary permeability and secondary outcomes were disease severity scores and ventilator-free days, among others. Results: Baseline characteristics were similar; in 87% of patients the PLI was above normal and in 90% mechanical or noninvasive ventilation was instituted at a median lung injury score of 2.5. There was no evidence that Rh-APC treatment affected the PLI or attenuated lung injury and sequential organ failure assessment scores. Mean ventilator-free days amounted to 14 (rh-APC) and 12 days (saline, P = 0.35). 28-day mortality was 6% in rh-APC- and 18% in saline-treated patients (P = 0.12). There was no difference in bleeding events. The study was prematurely discontinued because rh-APC was withdrawn from the market. Conclusion: There is no evidence that treatment with intravenous rh-APC during 4 days for infectious or inflammatory ARDS ameliorates increased alveolocapillary permeability or the clinical course of ARDS patients. We cannot exclude underpowering. Trial Registration: Nederlands Trial Registe

Lack of evidence for a causal role of CALR3 in monogenic cardiomyopathy

The pathogenicity of previously published disease-associated genes and variants is sometimes questionable. Large-scale, population-based sequencing studies have uncovered numerous false assignments of pathogenicity. Misinterpretation of sequence variants may have serious implications for the patients and families involved, as genetic test results are increasingly being used in medical decision making. In this study, we assessed the role of the calreticulin-3 gene (CALR3) in cardiomyopathy. CALR3 has been included in several cardiomyopathy gene panels worldwide. Its inclusion is based on a single publication describing two missense variants in patients with hypertrophic cardiomyopathy. In our national cardiomyopathy cohort (n = 6154), we identified 17 unique, rare heterozygous CALR3 variants in 48 probands. Overall, our patient cohort contained a significantly higher number of rare CALR3 variants compared to the ExAC population (p = 0.0036). However, after removing a potential Dutch founder variant, no statistically significant difference was found (p = 0.89). In nine probands, the CALR3 variant was accompanied by a disease-causing variant in another, well-known cardiomyopathy gene. In three families, the CALR3 variant did not segregate with the disease. Furthermore, we could not demonstrate calreticulin-3 protein expression in myocardial tissues at various ages. On the basis of these findings, it seems highly questionable that variants in CALR3 are a monogenic cause of cardiomyopathy

Leptodora kindtii survival in the laboratory

Leptodora kindtii , a pelagic predatory cladoceran, suffers high mortality on transfer to laboratory, which makes the experimental work difficult. We investigated the causes of high mortality, using four variables: water volume, animal density, light intensity, and origin of water for culturing, i.e., water from native or a non-native lake. For the experiments we used Leptodora and water from Lake Loosdrecht and Lake Maarsseveen (The Netherlands). Water was found to be the most important factor; the animals did not necessarily do better in lake water from which they were collected. Water volume and animal density were of limited importance, and light intensity did not affect survival.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41752/1/10452_2004_Article_DO00000328.pd

Over de vegetatie met Elatine hexandra (Lapierre) DC. in de kleine plas van het Lonnekermeer

In this paper a description is given of the vegetation in a pool near Hengelo (prov. of Overijssel). In the dry summers of 1975 and 1976, large parts of the shores and shallows of this pool ran dry. On these places a vegetation developed consisting mainly of Eleocharis acicularis, Elatine hexandra and to a lesser extent Juncus bulbosus. Presumably the first species is present permanently; it only flowers if its habitat runs dry. The annual Elatine hexandra was seen from July to as late as January. While in the course of summer and autumn the water level was sinking, Elatine died off in the upper zones and appeared in zones recently run dry. Somewhat later than the former two species, Juncus bulbosus developed. Whilst J. bulbosus is usually a perennial, in this pool it appeared as an annual. Locally Littorella uniflora was seen, always in open vegetation. In 1975 Eleocharis acicularis and Elatine hexandra were also seen locally in shallow water; the latter species flowered and fruited under these conditions. The four species mentioned above are characteristic for amphiphytic communities belonging to the alliance Littorellion. The ecology of these communities has been studied extensively in the Netherlands for some 40 years (SCHOOF-VAN PELT, 1973). Because of the rare occurrence of Elatine hexandra, this species’ ecology is relatively little known. Formerly, it was recorded chiefly in the Isoëto-Lobelietum, although it occurred most often in pools with slightly ‘enriched’ water, where this association which is very vulnerable to eutrophication lost ground. In recent years E. hexandra has been found several times in the El