UNLABELLED\nMETHODS\nRESULTS\nCONCLUSION\nBACKGROUND AND OBJECTIVES: Acute inflammation caused by infections or sepsis can impact pharmacokinetics. We used a model-based analysis to evaluate the... Show moreUNLABELLED\nMETHODS\nRESULTS\nCONCLUSION\nBACKGROUND AND OBJECTIVES: Acute inflammation caused by infections or sepsis can impact pharmacokinetics. We used a model-based analysis to evaluate the effect of acute inflammation as represented by interleukin-6 (IL-6) levels on drug clearance, focusing on renal glomerular filtration rate (GFR) and cytochrome P450 3A4 (CYP3A4)-mediated metabolism.\nA physiologically based model incorporating renal and hepatic drug clearance was implemented. Functions correlating IL-6 levels with GFR and in vitro CYP3A4 activity were derived and incorporated into the modeling framework. We then simulated treatment scenarios for hypothetical drugs by varying the IL-6 levels, the contribution of renal and hepatic drug clearance, and protein binding. The relative change in observed area under the concentration-time curve (AUC) was computed for these scenarios.\nInflammation showed opposite effects on drug exposure for drugs eliminated via the liver and kidney, with the effect of inflammation being inversely proportional to the extraction ratio (ER). For renally cleared drugs, the relative decrease in AUC was close to 30% during severe inflammation. For CYP3A4 substrates, the relative increase in AUC could exceed 50% for low-ER drugs. Finally, the impact of inflammation-induced changes in drug clearance is smaller for drugs with a larger unbound fraction.\nThis analysis demonstrates differences in the impact of inflammation on drug clearance for different drug types. The effects of inflammation status on pharmacokinetics may explain the inter-individual variability in pharmacokinetics in critically ill patients. The proposed model-based analysis may be used to further evaluate the effect of inflammation, i.e., by incorporating the effect of inflammation on other drug-metabolizing enzymes or physiological processes. Show less
BackgroundImplantation of a bioprosthetic valve is a reasonable choice for patients aged > 65 years. For middle-aged patients there is less certainty about whether a mechanical or bioprosthetic... Show moreBackgroundImplantation of a bioprosthetic valve is a reasonable choice for patients aged > 65 years. For middle-aged patients there is less certainty about whether a mechanical or bioprosthetic valve is best.MethodsThe Pericardial Surgical Aortic Valve Replacement (PERIGON) Pivotal Trial is evaluating the safety and efficacy of the Avalus bioprosthesis (Medtronic). We evaluated clinical and echocardiographic outcomes through 5 years of follow-up, stratified by age ≤ 65 and >65 years.ResultsTwo hundred seventy-one patients (24.2%) were ≤65 years old and 847 (75.8%) >65 years old. Most patients in both groups were men (217 [80.1%] vs 623 [73.6%], respectively; P = .031). Younger patients had a lower Society of Thoracic Surgeons risk of mortality (1.1% ± 0.9% vs 2.2% ± 1.4%, P < .001), better baseline New York Heart Association class (P = .004), and fewer comorbidities than older patients. At 5 years mortality was lower among younger than older patients (5.3% vs 14.0%, P < .001) and no cases of structural valve deterioration occurred in either group. Effective orifice area was similar between age groups (P = .11), and mean gradient was 13.9 ± 5.4 vs 12.0 ± 4.1 mm Hg (P < .001). Multivariable linear regression identified several parameters associated with mean aortic gradient at 5 years, including baseline age and mean aortic gradient, discharge stroke volume index and EOA, and implanted valve size. Ninety-five percent of patients were in New York Heart Association class I/II through 5 years in both age groups (P = .85).ConclusionsFindings from this analysis demonstrate satisfactory safety, hemodynamic performance, and durability of the Avalus bioprosthesis through a 5-year follow-up in patients aged ≤ 65 and >65 years. Show less
Sepsis is a life-threatening condition caused by a dysregulated host response to infection, it is associated with significant morbidity, mortality, and with a high financial burden on global... Show moreSepsis is a life-threatening condition caused by a dysregulated host response to infection, it is associated with significant morbidity, mortality, and with a high financial burden on global healthcare systems. Bacterial infections are the primary cause of sepsis, but the growing prevalence of antimicrobial resistance complicates the effectiveness of antimicrobial treatments. Moreover, limited understanding of the host immune response during sepsis hinders the discovery of valuable biomarkers and drug targets. As such, there is an urgent need to improve the treatment of sepsis. To tackle this challenge, we have concentrated our efforts on optimizing current treatment strategies and on facilitating the discovery of novel host inflammatory response directed therapeutics. In this thesis, we have utilized quantitative pharmacological modeling approaches to assess the adequacy of current dose regimens and to evaluate antibiotic pharmacokinetic variability, thereby optimizing antimicrobial therapies for sepsis. Additionally, our researches had aimed to deepen our understanding of the underlying dynamics of sepsis pathology, enabling the identification of promising biomarkers and therapeutic targets for sepsis. Our work demonstrated how quantitative modeling strategies can support the design of optimized treatment strategies, and how systematic model-based integration of disease mechanisms can help to overcome the translational challenges in sepsis drug development. Show less
Objective: To describe differences between North America and Europe in the perioperative management of patients undergoing surgical aortic valve replacement (SAVR). Methods: Patients with moderate... Show moreObjective: To describe differences between North America and Europe in the perioperative management of patients undergoing surgical aortic valve replacement (SAVR). Methods: Patients with moderate or greater aortic stenosis or regurgitation requiring SAVR were enrolled in a prospective observational cohort evaluating the safety and efficacy of a new stented bioprosthesis at 25 centres in North America (Canada and the USA) and 13 centres in Europe (Germany, the Netherlands, France, the UK, Switzerland and Italy). While all patients underwent implantation with the same bioprosthetic model, perioperative management was left to the discretion of participating centres. Perioperative care was described in detail including outcomes up to 1-year follow-up. Results: Among 1118 patients, 643 (58%) were implanted in North America, and 475 (42%) were implanted in Europe. Patients in Europe were older, had a lower body mass index, less bicuspid disease and worse degree of aortic stenosis at baseline. In Europe, anticoagulant therapy at discharge was more aggressive, whereas length of stay was longer, and discharges directly to home were less common. Rehospitalisation risk was lower in Europe at 30 days (8.5% vs 15.9%) but converged at 1-year follow-up (26.5% vs 28.1%). Within continents, there were major differences between individual countries concerning perioperative management. Conclusion: Contemporary perioperative management of SAVR patients varies between North America and Europe in patient selection, procedural techniques, antithrombotic regimen and discharge management. Furthermore, rehospitalisation differed largely between continents and countries. Hence, geographical setting must be considered during design and interpretation of trials on SAVR. Show less
Liu, F.; Aulin, L.B.S.; Kossen, S.S.A.; Cathalina, J.E.J.; Bremmer, M.; Foks, A.C.; ... ; Hasselt, J.G.C. van 2022
Sepsis is a life-threatening condition driven by the dysregulation of the host immune response to an infection. The complex and interacting mechanisms underlying sepsis remain not fully understood.... Show moreSepsis is a life-threatening condition driven by the dysregulation of the host immune response to an infection. The complex and interacting mechanisms underlying sepsis remain not fully understood. By integrating prior knowledge from literature using mathematical modelling techniques, we aimed to obtain a deeper mechanistic insight into sepsis pathogenesis and to evaluate promising novel therapeutic targets, with a focus on Toll-like receptor 4 (TLR4)-mediated pathways. A Boolean network of regulatory relationships was developed for key immune components associated with sepsis pathogenesis after TLR4 activation. Perturbation analyses were conducted to identify therapeutic targets associated with organ dysfunction or antibacterial activity. The developed model consisted of 42 nodes and 183 interactions. Perturbation analyses suggest that over-expression of tumour necrosis factor alpha (TNF-α) or inhibition of soluble receptor sTNF-R, tissue factor, and inflammatory cytokines (IFN-γ, IL-12) may lead to a reduced activation of organ dysfunction related endpoints. Over-expression of complement factor C3b and C5b led to an increase in the bacterial clearance related endpoint. We identified that combinatory blockade of IFN-γ and IL-10 may reduce the risk of organ dysfunction. Finally, we found that combining antibiotic treatment with IL-1β targeted therapy may have the potential to decrease thrombosis. In summary, we demonstrate how existing biological knowledge can be effectively integrated using Boolean network analysis for hypothesis generation of potential treatment strategies and characterization of biomarker responses associated with the early inflammatory response in sepsis. Show less
Liu, F.; Aulin, L.B.S.; Guo, T.; Krekels, E.H.J.; Moerland, M.; Graaf, P.H. van der; Hasselt, J.G.C. van 2022
Clinical studies in healthy volunteers challenged with lipopolysaccharide (LPS), a constituent of the cell wall of Gram-negative bacteria, represent a key model to characterize the Toll-like... Show moreClinical studies in healthy volunteers challenged with lipopolysaccharide (LPS), a constituent of the cell wall of Gram-negative bacteria, represent a key model to characterize the Toll-like receptor 4 (TLR4)-mediated inflammatory response. Here, we developed a mathematical modelling framework to quantitatively characterize the dynamics and inter-individual variability of multiple inflammatory biomarkers in healthy volunteer LPS challenge studies. Data from previously reported LPS challenge studies were used, which included individual-level time-course data for tumour necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), interleukin 8 (IL-8) and C-reactive protein (CRP). A one-compartment model with first-order elimination was used to capture the LPS kinetics. The relationships between LPS and inflammatory markers was characterized using indirect response (IDR) models. Delay differential equations were applied to quantify the delays in biomarker response profiles. For LPS kinetics, our estimates of clearance and volume of distribution were 35.7 L h(-1) and 6.35 L, respectively. Our model adequately captured the dynamics of multiple inflammatory biomarkers. The time delay for the secretion of TNF-alpha, IL-6 and IL-8 were estimated to be 0.924, 1.46 and 1.48 h, respectively. A second IDR model was used to describe the induced changes of CRP in relation to IL-6, with a delayed time of 4.2 h. The quantitative models developed in this study can be used to inform design of clinical LPS challenge studies and may help to translate preclinical LPS challenge studies to humans. Show less
OBJECTIVES This analysis evaluated the safety, durability and haemodynamic performance of a stented bovine pericardial valve through 5 years of follow-up in patients with an indication for surgical... Show moreOBJECTIVES This analysis evaluated the safety, durability and haemodynamic performance of a stented bovine pericardial valve through 5 years of follow-up in patients with an indication for surgical aortic valve replacement.METHODS Kaplan-Meier analysis was used to estimate the incidence of survival and valve-related thromboembolism, major paravalvular leak, endocarditis, structural valve deterioration (SVD) and reintervention. The mean aortic gradient and New York Heart Association (NYHA) functional class were also evaluated.RESULTS A total of 1118 patients have received the Avalus valve; 564 have completed the 5-year follow-up. The median follow-up was 4.85 years (4810 patient-years total follow-up). At baseline, the mean age was 70.2 +/- 9.0 years; 75.1% of patients were male. The Society of Thoracic Surgeons predicted risk of mortality was 2.0 +/- 1.4%. Most patients were in NYHA functional class II (46.8%) or III (40.3%). At the 5-year follow-up, the overall Kaplan-Meier survival rate was 88.1% (85.9-90.0%). The Kaplan-Meier event rates were 5.6% (4.3-7.2%) for thromboembolism, 4.4% (3.2-6.0%) for endocarditis, 0.2% (0.0-0.7%) for a major paravalvular leak and 3.2% (2.3-4.6%) for reintervention. There were no cases of SVD. The mean gradient decreased from 42.1 +/- 17.1 mmHg at baseline, to 13.1 +/- 4.7 mmHg at discharge and remained stable at 12.5 +/- 4.6 mmHg at 5 years. More than 95% of patients were in NYHA functional class I/II 5 years after surgery.CONCLUSIONS The findings of a high survival rate, excellent safety, no SVD and stable haemodynamic performance and functional status through 5 years of follow-up are encouraging. Additional follow-up is needed to assess the long-term durability of this contemporary surgical bioprosthesis. Show less
OBJECTIVESThis analysis evaluated the safety, durability and haemodynamic performance of a stented bovine pericardial valve through 5 years of follow-up in patients with an indication for surgical... Show moreOBJECTIVESThis analysis evaluated the safety, durability and haemodynamic performance of a stented bovine pericardial valve through 5 years of follow-up in patients with an indication for surgical aortic valve replacement.METHODSKaplan–Meier analysis was used to estimate the incidence of survival and valve-related thromboembolism, major paravalvular leak, endocarditis, structural valve deterioration (SVD) and reintervention. The mean aortic gradient and New York Heart Association (NYHA) functional class were also evaluated.RESULTSA total of 1118 patients have received the Avalus valve; 564 have completed the 5-year follow-up. The median follow-up was 4.85 years (4810 patient-years total follow-up). At baseline, the mean age was 70.2 ± 9.0 years; 75.1% of patients were male. The Society of Thoracic Surgeons predicted risk of mortality was 2.0 ± 1.4%. Most patients were in NYHA functional class II (46.8%) or III (40.3%). At the 5-year follow-up, the overall Kaplan–Meier survival rate was 88.1% (85.9–90.0%). The Kaplan–Meier event rates were 5.6% (4.3–7.2%) for thromboembolism, 4.4% (3.2–6.0%) for endocarditis, 0.2% (0.0–0.7%) for a major paravalvular leak and 3.2% (2.3–4.6%) for reintervention. There were no cases of SVD. The mean gradient decreased from 42.1 ± 17.1 mmHg at baseline, to 13.1 ± 4.7 mmHg at discharge and remained stable at 12.5 ± 4.6 mmHg at 5 years. More than 95% of patients were in NYHA functional class I/II 5 years after surgery.CONCLUSIONSThe findings of a high survival rate, excellent safety, no SVD and stable haemodynamic performance and functional status through 5 years of follow-up are encouraging. Additional follow-up is needed to assess the long-term durability of this contemporary surgical bioprosthesis. Show less
Azido sugars have found frequent use as probes of biological systems in approaches ranging from cell surface metabolic labeling to activity-based proteomic profiling of glycosidases. However,... Show moreAzido sugars have found frequent use as probes of biological systems in approaches ranging from cell surface metabolic labeling to activity-based proteomic profiling of glycosidases. However, little attention is typically paid to how well azide-substituted sugars represent the parent molecule, despite the substantial difference in size and structure of an azide compared to a hydroxyl. To quantitatively assess how well azides are accommodated, we have used glycosidases as tractable model enzyme systems reflecting what would also be expected for glycosyltransferases and other sugar binding/modifying proteins. In this vein, specificity constants have been measured for the hydrolysis of a series of azidodeoxy glucosides and N-acetylhexosaminides by a large number of glycosidases produced from expressed synthetic gene and metagenomic libraries. Azides at secondary carbons are not significantly accommodated, and thus, associated substrates are not processed, while those at primary carbons are productively recognized by only a small subset of the enzymes and often then only very poorly. Accordingly, in the absence of careful controls, results obtained with azide-modified sugars may not be representative of the situation with the natural sugar and should be interpreted with considerable caution. Azide incorporation can indeed provide a useful tool to monitor and detect glycosylation, but careful consideration should go into the selection of sites of azide substitution; such studies should not be used to quantitate glycosylation or to infer the absence of glycosylation activity. Show less
BACKGROUND\nMETHODS\nFINDINGS\nINTERPRETATION\nFUNDING\nSepsis is a major contributor to neonatal mortality, particularly in low-income and middle-income countries (LMICs). WHO advocates ampicillin... Show moreBACKGROUND\nMETHODS\nFINDINGS\nINTERPRETATION\nFUNDING\nSepsis is a major contributor to neonatal mortality, particularly in low-income and middle-income countries (LMICs). WHO advocates ampicillin-gentamicin as first-line therapy for the management of neonatal sepsis. In the BARNARDS observational cohort study of neonatal sepsis and antimicrobial resistance in LMICs, common sepsis pathogens were characterised via whole genome sequencing (WGS) and antimicrobial resistance profiles. In this substudy of BARNARDS, we aimed to assess the use and efficacy of empirical antibiotic therapies commonly used in LMICs for neonatal sepsis.\nIn BARNARDS, consenting mother-neonates aged 0-60 days dyads were enrolled on delivery or neonatal presentation with suspected sepsis at 12 BARNARDS clinical sites in Bangladesh, Ethiopia, India, Pakistan, Nigeria, Rwanda, and South Africa. Stillborn babies were excluded from the study. Blood samples were collected from neonates presenting with clinical signs of sepsis, and WGS and minimum inhibitory concentrations for antibiotic treatment were determined for bacterial isolates from culture-confirmed sepsis. Neonatal outcome data were collected following enrolment until 60 days of life. Antibiotic usage and neonatal outcome data were assessed. Survival analyses were adjusted to take into account potential clinical confounding variables related to the birth and pathogen. Additionally, resistance profiles, pharmacokinetic-pharmacodynamic probability of target attainment, and frequency of resistance (ie, resistance defined by in-vitro growth of isolates when challenged by antibiotics) were assessed. Questionnaires on health structures and antibiotic costs evaluated accessibility and affordability.\nBetween Nov 12, 2015, and Feb 1, 2018, 36 285 neonates were enrolled into the main BARNARDS study, of whom 9874 had clinically diagnosed sepsis and 5749 had available antibiotic data. The four most commonly prescribed antibiotic combinations given to 4451 neonates (77·42%) of 5749 were ampicillin-gentamicin, ceftazidime-amikacin, piperacillin-tazobactam-amikacin, and amoxicillin clavulanate-amikacin. This dataset assessed 476 prescriptions for 442 neonates treated with one of these antibiotic combinations with WGS data (all BARNARDS countries were represented in this subset except India). Multiple pathogens were isolated, totalling 457 isolates. Reported mortality was lower for neonates treated with ceftazidime-amikacin than for neonates treated with ampicillin-gentamicin (hazard ratio [adjusted for clinical variables considered potential confounders to outcomes] 0·32, 95% CI 0·14-0·72; p=0·0060). Of 390 Gram-negative isolates, 379 (97·2%) were resistant to ampicillin and 274 (70·3%) were resistant to gentamicin. Susceptibility of Gram-negative isolates to at least one antibiotic in a treatment combination was noted in 111 (28·5%) to ampicillin-gentamicin; 286 (73·3%) to amoxicillin clavulanate-amikacin; 301 (77·2%) to ceftazidime-amikacin; and 312 (80·0%) to piperacillin-tazobactam-amikacin. A probability of target attainment of 80% or more was noted in 26 neonates (33·7% [SD 0·59]) of 78 with ampicillin-gentamicin; 15 (68·0% [3·84]) of 27 with amoxicillin clavulanate-amikacin; 93 (92·7% [0·24]) of 109 with ceftazidime-amikacin; and 70 (85·3% [0·47]) of 76 with piperacillin-tazobactam-amikacin. However, antibiotic and country effects could not be distinguished. Frequency of resistance was recorded most frequently with fosfomycin (in 78 isolates [68·4%] of 114), followed by colistin (55 isolates [57·3%] of 96), and gentamicin (62 isolates [53·0%] of 117). Sites in six of the seven countries (excluding South Africa) stated that the cost of antibiotics would influence treatment of neonatal sepsis. Our data raise questions about the empirical use of combined ampicillin-gentamicin for neonatal sepsis in LMICs because of its high resistance and high rates of frequency of resistance and low probability of target attainment. Accessibility and affordability need to be considered when advocating antibiotic treatments with variance in economic health structures across LMICs. Funding: The Bill & Melinda Gates Foundation. Show less
Reisen, M.E.H. van; Aladipo, F.; Stokmans, M.; Mpezamihgo, M.; Folorunso, S.; Schultes, E.; ... ; Musen, M.A. 2021
The limited volume of COVID-19 data from Africa raises concerns for global genome research, which requires a diversity of genotypes for accurate disease prediction, including on the provenance of... Show moreThe limited volume of COVID-19 data from Africa raises concerns for global genome research, which requires a diversity of genotypes for accurate disease prediction, including on the provenance of the new SARS-CoV-2 mutations. The Virus Outbreak Data Network (VODAN)-Africa studied the possibility of increasing the production of clinical data, finding concerns about data ownership, and the limited use of health data for quality treatment at point of care. To address this, VODAN Africa developed an architecture to record clinical health data and research data collected on the incidence of COVID-19, producing these as human- and machine-readable data objects in a distributed architecture of locally governed, linked, human- and machine-readable data. This architecture supports analytics at the point of care and-through data visiting, across facilities-for generic analytics. An algorithm was run across FAIR Data Points to visit the distributed data and produce aggregate findings. The FAIR data architecture is deployed in Uganda, Ethiopia, Liberia, Nigeria, Kenya, Somalia, Tanzania, Zimbabwe, and Tunisia. Show less
Lieven, C.; Beber, M.E.; Olivier, B.G.; Bergmann, F.T.; Ataman, M.; Babaei. P.; ... ; Zhang, C. 2020
Inferring a person's smoking habit and history from blood is relevant for complementing or replacing self-reports in epidemiological and public health research, and for forensic applications.... Show moreInferring a person's smoking habit and history from blood is relevant for complementing or replacing self-reports in epidemiological and public health research, and for forensic applications. However, a finite DNA methylation marker set and a validated statistical model based on a large dataset are not yet available. Employing 14 epigenome-wide association studies for marker discovery, and using data from six population-based cohorts (N = 3764) for model building, we identified 13 CpGs most suitable for inferring smoking versus non-smoking status from blood with a cumulative Area Under the Curve (AUC) of 0.901. Internal fivefold cross-validation yielded an average AUC of 0.897 +/- 0.137, while external model validation in an independent population-based cohort (N = 1608) achieved an AUC of 0.911. These 13 CpGs also provided accurate inference of current (average AUC(crossvalidation) 0.925 +/- 0.021, AUC(externalvalidation)0.914), former (0.766 +/- 0.023, 0.699) and never smoking (0.830 +/- 0.019, 0.781) status, allowed inferring pack-years in current smokers (10 pack-years 0.800 +/- 0.068, 0.796; 15 pack-years 0.767 +/- 0.102, 0.752) and inferring smoking cessation time in former smokers (5 years 0.774 +/- 0.024, 0.760; 10 years 0.766 +/- 0.033, 0.764; 15 years 0.767 +/- 0.020, 0.754). Model application to children revealed highly accurate inference of the true non- smoking status (6 years of age: accuracy 0.994, N = 355; 10 years: 0.994, N = 309), suggesting prenatal and passive smoking exposure having no impact on model applications in adults. The finite set of DNA methylation markers allow accurate inference of smoking habit, with comparable accuracy as plasma cotinine use, and smoking history from blood, which we envision becoming useful in epidemiology and public health research, and in medical and forensic applications. Show less
