37 research outputs found
High-resolution quantification of root dynamics in split-nutrient rhizoslides reveals rapid and strong proliferation of maize roots in response to local high nitrogen
Patches rich in nitrogen are rapidly colonized by selective root growth in maize, which was quantified at high time resolution with state-of-the-art non-invasive imaging techniques in a paper-based growth syste
Combining agro-ecological functions in grass-clover mixtures
Grass-clover mixtures show many benefits for sustainable agriculture. In the Netherlands, organic farmers often work together in a so-called partner farm concept, with the aim to close nutrient cycles on a regional level. In this system, arable farms grow one-year grass-clover leys, as fodder for a livestock farm, in exchange for, e.g., manure. This practice could also be used in the transition of conventional farms towards a more circular regenerative and nature inclusive agriculture. In the current experiment we assessed the effect of a range of grass (Lolium perenne: Lp, Lolium multiflorum: Lm) and clover (Trifolium pratense: Tp and Trifolium repens: Tr) monocultures and mixtures on both below- and aboveground parameters in light of benefits for livestock and arable farms, and biodiversity. The grass monocultures showed good weed suppression, high root density, and especially Lp had a positive effect on soil structure. Clover, on the other hand, showed high herbage dry matter yield (particularly Tp) and Nitrogen (N) yield, and Tr showed high digestibility. Moreover, clover had a positive effect on the soil mineral N, and earthworm abundance tended to be higher in the clover monocultures. When (some of) the four species were combined in grass-clover mixtures, they combined the positive effects of the species and often even outperformed the (best) monocultures. We concluded that grass-clover mixtures increased agro-ecological functions
Efficacy and Safety of High Potent P2Y12 Inhibitors Prasugrel and Ticagrelor in Patients With Coronary Heart Disease Treated With Dual Antiplatelet Therapy: A Sex-Specific Systematic Review and Meta-Analysis
Background Sex differences in efficacy and safety of dual antiplatelet therapy remain uncertain because of the underrepresentation of women in cardiovascular trials. The aim of this study was to perform a sex-specific analysis of the pooled efficacy and safety data of clinical trials comparing a high potent P2Y12 inhibitor+aspirin with clopidogrel+aspirin in patients with acute coronary syndrome. Methods and Results A systematic literature search was performed. Randomized clinical trials that compared patients following percutaneous coronary intervention/acute coronary syndrome who were taking high potent P2Y12 inhibitors+aspirin versus clopidogrel+aspirin were selected. Random effects estimates were calculated and relative risks with 95% CIs on efficacy and safety end points were determined per sex. We included 6 randomized clinical trials comparing prasugrel/ticagrelor versus clopidogrel in 43 990 patients (13 030 women), with a median follow-up time of 1.06 years. Women and men had similar relative risk (RR) reduction for major cardiovascular events (women: RR, 0.89 [95% CI, 0.80-1.00; men: RR, 0.84 [95% CI, 0.79-0.91) (P for interaction=0.39). Regarding safety, women and men had similar risk of major bleeding by high-potency dual antip
Microbial Transformations of Nitrogen, Sulfur, and Iron Dictate Vegetation Composition in Wetlands: A Review
The majority of studies on rhizospheric interactions focus on pathogens, mycorrhizal symbiosis, or carbon transformations. Although the biogeochemical transformations of N, S, and Fe have profound effects on vegetation, these effects have received far less attention. This review, meant for microbiologists, biogeochemists, and plant scientists includes a call for interdisciplinary research by providing a number of challenging topics for future ecosystem research. Firstly, all three elements are plant nutrients, and microbial activity significantly changes their availability. Secondly, microbial oxidation with oxygen supplied by radial oxygen loss from roots in wetlands causes acidification, while reduction using alternative electron acceptors leads to generation of alkalinity, affecting pH in the rhizosphere, and hence plant composition. Thirdly, reduced species of all three elements may become phytotoxic. In addition, Fe cycling is tightly linked to that of S and P. As water level fluctuations are very common in wetlands, rapid changes in the availability of oxygen and alternative terminal electron acceptors will result in strong changes in the prevalent microbial redox reactions, with significant effects on plant growth. Depending on geological and hydrological settings, these interacting microbial transformations change the conditions and resource availability for plants, which are both strong drivers of vegetation development and composition by changing relative competitive strengths. Conversely, microbial composition is strongly driven by vegetation composition. Therefore, the combination of microbiological and plant ecological knowledge is essential to understand the biogeochemical and biological key factors driving heterogeneity and total (i.e., microorganisms and vegetation) community composition at different spatial and temporal scales
Endogenous Abscisic Acid as a Key Switch for Natural Variation in Flooding-Induced Shoot Elongation
Somatostatin receptor scintigraphy with [111In-DTPA-d-Phe1]- and [123I-Tyr3]-octreotide: the Rotterdam experience with more than 1000 patients
Various tumours, classically specified as either neuroendocrine or non-neuroendocrine, contain high numbers of somatostatin receptors, which enable in vivo localization of the primary tumour and its metastases by scintigraphy with the radiolabelled somatostatin analogue octreotide. In addition granulomas and autoimmune processes can be visualized because of local accumulation of somatostatin receptor-positive activated mononuclear leucocytes. In many instances a positive scintigram predicts a favourable response to treatment with octreotide. It is tempting to speculate that octreotide labelled with an appropriate radionuclide might be used in cancer therapy. The successful application of radiolabelled octreotide in scintigraphy indicates the possible usefulness of other radiolabelled peptides, either native peptides or derivatives of these, in, for example, nuclear oncology. The small size of these peptides, e.g. bombesin and substance P, is of the utmost importance for a relatively fast blood clearance, thus leading to low background radioactivity. In this way peptides are powerful alternatives to (fragments of) monoclonal antibodies, the application of which to scintigraphic localization of specific cell surface antigen-bearing tumours is plagued by slow blood clearance and, hence, high background levels
Hepatic Cyst Infection During Use of the Somatostatin Analog Lanreotide in Autosomal Dominant Polycystic Kidney Disease: An Interim Analysis of the Randomized Open-Label Multicenter DIPAK-1 Study
Introduction and Aims: The DIPAK-1 Study investigates the reno- and hepatoprotective efficacy of the somatostatin analog lanreotide compared with standard care in patients with later stage autosomal dominant polycystic kidney disease (ADPKD). During this trial, we witnessed several episodes of hepatic cyst infection, all during lanreotide treatment. We describe these events and provide a review of the literature. Methods: The DIPAK-1 Study is an ongoing investigator-driven, randomized, controlled, open-label multicenter trial. Patients (ADPKD, ages 18–60 years, estimated glomerular filtration rate 30–60 mL/min/1.73 m2) were randomized 1:1 to receive lanreotide 120 mg subcutaneously every 28 days or standard care during 120 weeks. Hepatic cyst infection was diagnosed by local physicians. Results: We included 309 ADPKD patients of which seven (median age 53 years [interquartile range: 48–55], 71% female, median estimated glomerular filtration rate 42 mL/min/1.73 m2 [interquartile range: 41–58]) developed eight episodes of hepatic cyst infection during 342 patient-years of lanreotide use (0.23 cases per 10 patient-years). These events were limited to patients receiving lanreotide (p < 0.001 vs. standard care). Baseline characteristics were similar between subjects who did or did not develop a hepatic cyst infection during lanreotide use, except for a history of hepatic cyst infection (29 vs. 0.7%, p < 0.001). Previous studies with somatostatin analogs reported cyst infections, but did not identify a causal relationship. Conclusions: These data suggest an increased risk for hepatic cyst infection during use of somatostatin analogs, especially in ADPKD patients with a history of hepatic cyst infection. The main results are still awaited to fully appreciate the risk–benefit ratio. ClinicalTrials.gov identifier: NCT 01616927
A Co-Opted Hormonal Cascade Activates Dormant Adventitious Root Primordia upon Flooding in Solanum
Heritability estimates for 361 blood metabolites across 40 genome-wide association studies
Metabolomics examines the small molecules involved in cellular metabolism. Approximately 50% of total phenotypic differences in metabolite levels is due to genetic variance, but heritability estimates differ across metabolite classes. We perform a review of all genome-wide association and (exome-) sequencing studies published between November 2008 and October 2018, and identify >800 class-specific metabolite loci associated with metabolite levels. In a twin-family cohort (N = 5117), these metabolite loci are leveraged to simultaneously estimate total heritability (h2 total), and the proportion of heritability captured by known metabolite loci (h2 Metabolite-hits) for 309 lipids and
Genome-wide analyses identify a role for SLC17A4 and AADAT in thyroid hormone regulation.
Thyroid dysfunction is an important public health problem, which affects 10% of the general population and increases the risk of cardiovascular morbidity and mortality. Many aspects of thyroid hormone regulation have only partly been elucidated, including its transport, metabolism, and genetic determinants. Here we report a large meta-analysis of genome-wide association studies for thyroid function and dysfunction, testing 8 million genetic variants in up to 72,167 individuals. One-hundred-and-nine independent genetic variants are associated with these traits. A genetic risk score, calculated to assess their combined effects on clinical end points, shows significant associations with increased risk of both overt (Graves' disease) and subclinical thyroid disease, as well as clinical complications. By functional follow-up on selected signals, we identify a novel thyroid hormone transporter (SLC17A4) and a metabolizing enzyme (AADAT). Together, these results provide new knowledge about thyroid hormone physiology and disease, opening new possibilities for therapeutic targets