Dynamics of the Gut Microbiota in Children Receiving Selective or Total Gut Decontamination Treatment during Hematopoietic Stem Cell Transplantation

Bloodstream infections and graft-versus-host disease are common complications after hematopoietic stem cell transplantation (HSCT) procedures, associated with the gut microbiota that acts as a reservoir for opportunistic pathogens. Selective gut decontamination (SGD) and total gut decontamination (TGD) during HSCT have been associated with a decreased risk of developing these complications after transplantation. However, because studies have shown conflicting results, the use of these treatments remains subject of debate. In addition, their impact on the gut microbiota is not well studied. The aim of this study was to elucidate the dynamics of the microbiota during and after TGD and to compare these with the dynamics of SGD. In this prospective, observational, single center study fecal samples were longitudinally collected from 19 children eligible for allogenic HSCT (TGD, n=12; SGD, n=7), weekly during hospital admission and monthly after discharge. In addition, fecal samples were collected from 3 family stem cell donors. Fecal microbiota structure of patients and donors was determined by 16S rRNA gene amplicon sequencing. Microbiota richness and diversity markedly decreased during SGD and TGD and gradually increased after cessation of decontamination treatment. During SGD, gut microbiota composition was relatively stable and dominated by Bacteroides, whereas it showed high inter- and intraindividual variation and low Bacteroides abundance during TGD. In some children TGD allowed the genera Enterococcus and Streptococcus to thrive during treatment. A gut microbiota dominated by Bacteroides was associated with increased predicted activity of several metabolic processes. Comparing the microbiota of recipients and their donors indicated that receiving an SCT did not alter the patient's microbiota to become more similar to that of its donor. Overall, our findings indicate that SGD and TGD affect gut microbiota structure in a treatment-specific manner. Whether these treatments affect clinical outcomes via interference with the gut microbiota needs to be further elucidated. (C) 2019 American Society for Blood and Marrow Transplantation.Peer reviewe

Antithrombotic therapy in patients undergoing TAVI: An overview of Dutch hospitals

Purpose To assess current antithrombotic treatment strategies in the Netherlands in patients undergoing transcatheter aortic valve implantation (TAVI). Methods For every Dutch hospital performing TAVI (n =14) an interventional cardiologist experienced in performing TAVI was interviewed concerning heparin, aspirin, thienopyridine and oral anticoagulation treatment in patients undergoing TAVI. Results The response rate was 100 %. In every centre, a protocol for antithrombotic treatment after TAVI was available. Aspirin was prescribed in all centres, concomitant clopidogrel was prescribed 13 of the 14 centres. Duration of concomitant clopidogrel was 3 months in over twothirds of cases. In 2 centres, duration of concomitant clopidogrel was based upon type of prosthesis: 6 months versus 3 months for supra-annular and intra-annular prostheses, respectively. Conclusions Leaning on a small basis of evidence and recommendations, the antithrombotic policy for patients undergoing TAVI is highly variable in the Netherlands. As a standardised regimen might further reduce haemorrhagic complications, large randomised clinical trials may help to establish the most appropriate approach

Acute Multiple Organ Failure in Adult Mice Deleted for the Developmental Regulator Wt1

There is much interest in the mechanisms that regulate adult tissue homeostasis and their relationship to processes governing foetal development. Mice deleted for the Wilms' tumour gene, Wt1, lack kidneys, gonads, and spleen and die at mid-gestation due to defective coronary vasculature. Wt1 is vital for maintaining the mesenchymal–epithelial balance in these tissues and is required for the epithelial-to-mesenchyme transition (EMT) that generates coronary vascular progenitors. Although Wt1 is only expressed in rare cell populations in adults including glomerular podocytes, 1% of bone marrow cells, and mesothelium, we hypothesised that this might be important for homeostasis of adult tissues; hence, we deleted the gene ubiquitously in young and adult mice. Within just a few days, the mice suffered glomerulosclerosis, atrophy of the exocrine pancreas and spleen, severe reduction in bone and fat, and failure of erythropoiesis. FACS and culture experiments showed that Wt1 has an intrinsic role in both haematopoietic and mesenchymal stem cell lineages and suggest that defects within these contribute to the phenotypes we observe. We propose that glomerulosclerosis arises in part through down regulation of nephrin, a known Wt1 target gene. Protein profiling in mutant serum showed that there was no systemic inflammatory or nutritional response in the mutant mice. However, there was a dramatic reduction in circulating IGF-1 levels, which is likely to contribute to the bone and fat phenotypes. The reduction of IGF-1 did not result from a decrease in circulating GH, and there is no apparent pathology of the pituitary and adrenal glands. These findings 1) suggest that Wt1 is a major regulator of the homeostasis of some adult tissues, through both local and systemic actions; 2) highlight the differences between foetal and adult tissue regulation; 3) point to the importance of adult mesenchyme in tissue turnover

Mendelian randomization integrating GWAS and eQTL data reveals genetic determinants of complex and clinical traits

Genome-wide association studies (GWAS) have identified thousands of variants associated with complex traits, but their biological interpretation often remains unclear. Most of these variants overlap with expression QTLs, indicating their potential involvement in regulation of gene expression. Here, we propose a transcriptome-wide summary statistics-based Mendelian Randomization approach (TWMR) that uses multiple SNPs as instruments and multiple gene expression traits as exposures, simultaneously. Applied to 43 human phenotypes, it uncovers 3,913 putatively causal gene-trait associations, 36% of which have no genome-wide significant SNP nearby in previous GWAS. Using independent association summary statistics, we find that the majority of these loci were missed by GWAS due to power issues. Noteworthy among these links is educational attainment-associated BSCL2, known to carry mutations leading to a Mendelian form of encephalopathy. We also find pleiotropic causal effects suggestive of mechanistic connections. TWMR better accounts for pleiotropy and has the potential to identify biological mechanisms underlying complex traits

Optimal Medical Therapy Prescription in Patients with Acute Coronary Syndrome in the Netherlands:A Multicenter Pilot Registry

Contains fulltext : 235316.pdf (Publisher’s version ) (Open Access)BACKGROUND: Unlike neighboring countries, the Netherlands does not have a national acute coronary syndrome (ACS) registry to evaluate quality of care. OBJECTIVE: We conducted a pilot registry in two hospitals to assess the prescription of guideline-recommended therapies in Dutch patients with ACS. METHODS: We included all consecutive patients with ST-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) (n = 1309) admitted to two Dutch percutaneous coronary intervention centers between March 2015 and February 2016. We collected follow-up medication use and reasons for discontinuation at discharge and 1, 6, and 12 months post-discharge. We assessed the use of optimal medical therapy (OMT), defined as the combined prescription of aspirin, P2Y12 inhibitors, statins, β-blockers, and angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. RESULTS: OMT prescription was 43.2% at discharge, 60.1% at 1 month, and 28.7% at 12 months. At 1 month, OMT prescription was significantly lower in patients with NSTEMI (51.8 vs. 65.7% for STEMI; p < 0.001). OMT prescription was lower in women (6 months: 55.4 vs. 62.0%, p = 0.036) and in elderly patients. CONCLUSION: In this pilot study that aimed to extend a national Dutch ACS registry to patients with STEMI and NSTEMI, OMT prescription was comparable to that in other local registries, was lower in women and patients with NSTEMI, and decreased with increasing age

Risks of Opioids in ST-Elevation Myocardial Infarction:A Review

Although opioids are recommended and frequently used in the acute phase of ST-elevation myocardial infarction (STEMI), their use is accompanied by serious side effects. In particular, gastrointestinal adverse effects may disturb absorption of essential oral medication like platelet inhibitors. This may cause suboptimal platelet inhibition and increased risk of acute stent thrombosis. Some clinical studies have already demonstrated these negative results. Alternative strategies to optimize platelet inhibition and pain relief in STEMI are being investigated. Clinicians should become more aware of the potential side effects of opioids in STEMI

Outcomes with P2Y12 inhibitor monotherapy after PCI according to bleeding risk: A Bayesian meta-analysis

Background: P2Y12 inhibitor monotherapy is a promising novel strategy to reduce bleeding complications compared to dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). In order to personalise treatment with DAPT based on patients' bleeding risk, we compared outcomes after PCI between P2Y12 inhibitor monotherapy and DAPT according to bleeding risk. Methods: A search for randomized clinical trials (RCTs) comparing P2Y12 inhibitor monotherapy after a short period of DAPT to standard DAPT after PCI was performed. Outcome differences between treatment groups regarding major bleedings, major adverse cardiac and cerebral events (MACCE) and net adverse clinical events (NACE) were assessed with hazard ratios (HRs) and corresponding credible intervals (CrI) according a Bayesian random effects model in patients with and without high bleeding risk (HBR). Results: Five RCTs including 30,084 patients were selected. P2Y12 inhibitor monotherapy compared to DAPT reduced major bleedings in the total population (HR: 0.65, 95 % CrI: 0.44 to 0.92). The HRs of the HBR and non-HBR subgroups showed a similar reduction of bleedings for monotherapy (HBR: HR 0.66, 95 % CrI: 0.25 to 1.74; non-HBR: HR 0.63, 95 % CrI: 0.36 to 1.09). No notable differences between treatments on MACCE and NACE were observed in either sub-group or in the total population. Conclusions: Regardless of bleeding risk, P2Y12 inhibitor monotherapy is the favourable choice after PCI regarding major bleedings and does not increase ischemic events compared to DAPT. This suggests that bleeding risk is not decisive when considering P2Y12 inhibitor monotherapy

The effect of raloxifene on bone marrow adipose tissue and bone turnover in postmenopausal women with osteoporosis

In patients with postmenopausal osteoporosis low bone volume is associated with high bone marrow adipose tissue (MAT). Moreover, high MAT is associated with increased fracture risk. This suggests an interaction between MAT and bone turnover, however literature remains equivocal. Estrogen treatment decreases MAT, but the effect of raloxifene, a selective estrogen receptor modulator (SERM) registered for treatment of postmenopausal osteoporosis, on MAT is not known. The aim of this study is 1] to determine the effect of raloxifene on MAT and 2] to determine the relationship between MAT and bone turnover in patients with osteoporosis. Bone biopsies from the MORE trial were analyzed. The MORE trial investigated the effects of raloxifene 60 or 120 mg per day versus placebo on bone metabolism and fracture incidence in patients with postmenopausal osteoporosis. We quantified MAT in iliac crest biopsies obtained at baseline and after 2 years of treatment (n = 53; age 68.2 ± 6.2 years). Raloxifene did not affect the change in MAT volume after 2 years compared to baseline (placebo: 1.89 ± 10.84%, raloxifene 60 mg: 6.31 ± 7.22%, raloxifene 120 mg: − 0.77 ± 10.72%), nor affected change in mean adipocyte size (placebo: 1.45 (4.45) μm, raloxifene 60 mg: 1.45 (4.35) μm, raloxifene 120 mg: 0.81 (5.21) μm). Adipocyte number tended to decrease after placebo treatment (− 9.92 (42.88) cells/mm2) and tended to increase during raloxifene 60 mg treatment (13.27 (66.14) cells/mm2) while adipocyte number remained unchanged in the raloxifene 120 mg group, compared to placebo (3.06 (39.80) cells/mm2, Kruskal-Wallis p = 0.055, post hoc: placebo vs raloxifene 60 mg p = 0.017). MAT volume and adipocyte size were negatively associated with osteoclast number at baseline (R2 = 0.123, p = 0.006 and R2 = 0.098, p = 0.016 respectively). Furthermore adipocyte size was negatively associated with osteoid surface (R2 = 0.067, p = 0.049). Finally, patients with vertebral fractures had higher MAT volume (50.82 (8.80)%) and larger adipocytes (55.75 (3.14) μm) compared to patients without fractures (45.58 (12.72)% p = 0.032, 52.77 (3.73) μm p = 0.004 respectively). In conclusion, raloxifene did not affect marrow adipose tissue, but tended to increase adipocyte number compared to placebo. At baseline MAT volume and adipocyte size were associated with bone resorption, and adipocyte size was associated with osteoid surface, suggesting an interaction between bone marrow adipocytes and bone turnover. In addition, we found that high MAT volume and larger adipocyte size are associated with prevalent vertebral fractures in postmenopausal women with osteoporosis, indicating that adipocyte size affects bone quality independent of bone volume

Bivalirudin versus heparin with or without glycoprotein IIb/IIIa inhibitors in patients with STEMI undergoing primary percutaneous coronary intervention:pooled patient-level analysis from the HORIZONS-AMI and EUROMAX trials

AbstractBackgroundIn the HORIZONS-AMI (Harmonizing Outcomes with RevasculariZatiON and Stents in Acute Myocardial Infarction) trial, 3,602 patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) treated with bivalirudin had lower bleeding and mortality rates, but higher acute stent thrombosis rates compared with heparin + a glycoprotein IIb/IIIa inhibitor (GPI). Subsequent changes in primary PCI, including the use of potent P2Y12 inhibitors, frequent radial intervention, and pre-hospital medication administration, were incorporated into the EUROMAX (European Ambulance Acute Coronary Syndrome Angiography) trial, which assigned 2,218 patients to bivalirudin versus heparin ± GPI before primary PCI.ObjectivesThe goal of this study was to examine the outcomes of procedural anticoagulation with bivalirudin versus heparin ± GPI for primary PCI, given the evolution in primary PCI.MethodsDatabases from HORIZONS-AMI and EUROMAX were pooled for patient-level analysis. The Breslow-Day test evaluated heterogeneity between trials.ResultsA total of 5,800 patients were randomized to bivalirudin (n = 2,889) or heparin ± GPI (n = 2,911). The radial approach was used in 21.3% of patients, prasugrel/ticagrelor was used in 18.1% of patients, and GPI was used in 84.8% of the control group. Bivalirudin compared with heparin ± GPI resulted in reduced 30-day rates of major bleeding (4.2% vs. 7.8%; relative risk [RR]: 0.53; 95% confidence interval [CI]: 0.43 to 0.66; p < 0.0001), thrombocytopenia (1.4% vs. 2.9%, RR: 0.48; 95% CI: 0.33 to 0.71; p = 0.0002), and cardiac mortality (2.0% vs. 2.9%; RR: 0.70; 95% CI: 0.50 to 0.97; p = 0.03), with nonsignificantly different rates of reinfarction, ischemia-driven revascularization, stroke, and all-cause mortality. Bivalirudin resulted in increased acute (<24 h) stent thrombosis rates (1.2% vs. 0.2%; RR: 6.04; 95% CI: 2.55 to 14.31; p < 0.0001), with nonsignificantly different rates of subacute stent thrombosis. Composite net adverse clinical events were lower with bivalirudin (8.8% vs. 11.9%; RR: 0.74; 95% CI: 0.63 to 0.86; p < 0.0001). There was no significant heterogeneity between the 2 trials for these outcomes, and results were consistent across major subgroups.ConclusionsDespite increased acute stent thrombosis, primary PCI with bivalirudin improved 30-day net clinical outcomes, with significant reductions in major bleeding, thrombocytopenia, and transfusions compared with heparin ± GPI, results that were consistent with evolution in PCI technique and pharmacotherapy. (Harmonizing Outcomes with RevasculariZatiON and Stents in Acute Myocardial Infarction [HORIZONS-AMI]; NCT00433966) (European Ambulance Acute Coronary Syndrome Angiography [EUROMAX]; NCT01087723