Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
56
result(s) for
"Rahmel, Tim"
Sort by:
Long-term mortality and outcome in hospital survivors of septic shock, sepsis, and severe infections: The importance of aftercare
by
Schepanek, Kaspar
,
Schmitz, Stefanie
,
Halberstadt, Peter
in
Aftercare - methods
,
Aged
,
Analysis
2020
Patients with severe infections and especially sepsis have a high in-hospital mortality, but even hospital survivors face long-term sequelae, decreased health-related quality of life, and high risk of death, suggesting a great need for specialized aftercare. However, data regarding a potential benefit of post-discharge rehabilitation in these patients are scarce. In this retrospective matched cohort study the claim data of a large German statutory health care insurer was analyzed. 83,974 hospital survivors having suffered from septic shock, sepsis, and severe infections within the years 2009-2016 were identified using an ICD abstraction strategy closely matched to the current Sepsis-3 definition. Cases were analyzed and compared with their matched pairs to determine their 5-year mortality and the impact of post-discharge rehabilitation. Five years after hospital discharge, mortality of initial hospital survivors were still increased after septic shock (HRadj 2.03, 95%-CI 1.87 to 2.19; P<0.001), sepsis (HRadj 1.73, 95%-CI 1.71 to 1.76; P<0.001), and also in survivors of severe infections without organ dysfunction (HRadj 1.70, 95%-CI 1.65 to 1.74; P<0.001) compared to matched controls without infectious diseases. Strikingly, patients treated in rehabilitation facilities showed a significantly improved 5-year survival after suffering from sepsis or septic shock (HRadj 0.81, 95%-CI 0.77 to 0.85; P<0.001) as well as severe infections without organ dysfunction (HRadj 0.81, 95%-CI 0.73 to 0.90; P<0.001) compared to matched patients discharged to home or self-care. Long-term mortality and morbidity of hospital survivors are markedly increased after septic shock, sepsis and severe infections without organ dysfunction, but best 5-year survival was recorded in patients discharged to a rehabilitation facility in all three groups. Thus, our data suggest that specialized aftercare programs may help to improve long-term outcome in these patients and warrants more vigilance in future investigations.
Journal Article
Very‐low‐carbohydrate diet enhances human T‐cell immunity through immunometabolic reprogramming
2021
Very‐low‐carbohydrate diet triggers the endogenous production of ketone bodies as alternative energy substrates. There are as yet unproven assumptions that ketone bodies positively affect human immunity. We have investigated this topic in an
in vitro
model using primary human T cells and in an immuno‐nutritional intervention study enrolling healthy volunteers. We show that ketone bodies profoundly impact human T‐cell responses. CD4
+
, CD8
+
, and regulatory T‐cell capacity were markedly enhanced, and T memory cell formation was augmented. RNAseq and functional metabolic analyses revealed a fundamental immunometabolic reprogramming in response to ketones favoring mitochondrial oxidative metabolism. This confers superior respiratory reserve, cellular energy supply, and reactive oxygen species signaling. Our data suggest a very‐low‐carbohydrate diet as a clinical tool to improve human T‐cell immunity. Rethinking the value of nutrition and dietary interventions in modern medicine is required.
SYNOPSIS
Ketogenic diet (KD) is characterized by a very limited uptake of carbohydrates, resulting in endogenous production of ketone bodies. This study identifies KD as a potent nutritional immunometabolic intervention to reprogram human T cell immunometabolism, favouring mitochondrial oxidative phosphorylation, thus enhancing both effector and regulatory T cell immune capacity and priming human T cells towards memory cell formation.
KD augmented human CD4
+
and CD8
+
T cell cytokine production and cell lysis capacity
in vitro
and
in vivo
.
Additionally, KD also enhanced regulatory T cell abundance and function, and primed human T cells to memory cell formation.
In response to KD, increased mitochondrial mass, ETC complex formation, aerobic oxidative phosphorylation capacity and ‐tightly controlled‐ ROS production was identified in human T cells.
Transcriptomic analysis revealed fundamental immunometabolic reprogramming of human CD4
+
and CD8
+
T cells after 3 weeks of KD.
Both, elevated bioenergetic capacity and ROS ‐serving as T‐cell second messenger molecules‐ provide the immunometabolic basis for enhanced T cell immunity on a KD.
Graphical Abstract
Ketogenic diet (KD) is characterized by a very limited uptake of carbohydrates, resulting in endogenous production of ketone bodies. This study identifies KD as a potent nutritional immunometabolic intervention to reprogram human T cell immunometabolism, favouring mitochondrial oxidative phosphorylation, thus enhancing both effector and regulatory T cell immune capacity and priming human T cells towards memory cell formation.
Journal Article
Mitochondrial dysfunction in sepsis is associated with diminished intramitochondrial TFAM despite its increased cellular expression
by
Koos, Björn
,
Thon, Patrick
,
Adamzik, Michael
in
631/250/256/1980
,
692/420/256/1980
,
692/420/256/2516
2020
Sepsis is characterized by a dysregulated immune response, metabolic derangements and bioenergetic failure. These alterations are closely associated with a profound and persisting mitochondrial dysfunction. This however occurs despite increased expression of the nuclear-encoded transcription factor A (TFAM) that normally supports mitochondrial biogenesis and functional recovery. Since this paradox may relate to an altered intracellular distribution of TFAM in sepsis, we tested the hypothesis that enhanced extramitochondrial TFAM expression does not translate into increased intramitochondrial TFAM abundance. Accordingly, we prospectively analyzed PBMCs both from septic patients (n = 10) and lipopolysaccharide stimulated PBMCs from healthy volunteers (n = 20). Extramitochondrial TFAM protein expression in sepsis patients was 1.8-fold greater compared to controls (p = 0.001), whereas intramitochondrial TFAM abundance was approximate 80% less (p < 0.001). This was accompanied by lower mitochondrial DNA copy numbers (p < 0.001), mtND1 expression (p < 0.001) and cellular ATP content (p < 0.001) in sepsis patients. These findings were mirrored in lipopolysaccharide stimulated PBMCs taken from healthy volunteers. Furthermore, TFAM-TFB2M protein interaction within the human mitochondrial core transcription initiation complex, was 74% lower in septic patients (p < 0.001). In conclusion, our findings, which demonstrate a diminished mitochondrial TFAM abundance in sepsis and endotoxemia, may help to explain the paradox of lacking bioenergetic recovery despite enhanced TFAM expression.
Journal Article
Machine learning identifies ICU outcome predictors in a multicenter COVID-19 cohort
2021
Background
Intensive Care Resources are heavily utilized during the COVID-19 pandemic. However, risk stratification and prediction of SARS-CoV-2 patient clinical outcomes upon ICU admission remain inadequate. This study aimed to develop a machine learning model, based on retrospective & prospective clinical data, to stratify patient risk and predict ICU survival and outcomes.
Methods
A Germany-wide electronic registry was established to pseudonymously collect admission, therapeutic and discharge information of SARS-CoV-2 ICU patients retrospectively and prospectively. Machine learning approaches were evaluated for the accuracy and interpretability of predictions. The Explainable Boosting Machine approach was selected as the most suitable method. Individual, non-linear shape functions for predictive parameters and parameter interactions are reported.
Results
1039 patients were included in the Explainable Boosting Machine model, 596 patients retrospectively collected, and 443 patients prospectively collected. The model for prediction of general ICU outcome was shown to be more reliable to predict “survival”. Age, inflammatory and thrombotic activity, and severity of ARDS at ICU admission were shown to be predictive of ICU survival. Patients’ age, pulmonary dysfunction and transfer from an external institution were predictors for ECMO therapy. The interaction of patient age with D-dimer levels on admission and creatinine levels with SOFA score without GCS were predictors for renal replacement therapy.
Conclusions
Using Explainable Boosting Machine analysis, we confirmed and weighed previously reported and identified novel predictors for outcome in critically ill COVID-19 patients. Using this strategy, predictive modeling of COVID-19 ICU patient outcomes can be performed overcoming the limitations of linear regression models.
Trial registration
“ClinicalTrials” (clinicaltrials.gov) under NCT04455451.
Journal Article
Randomised controlled study investigating standard dose continuous renal replacement therapy (CRRT) versus low-dose CRRT in critically ill patients with acute kidney injury (AKI): study protocol for a prospective, randomised, controlled, international, multicentre trial (the ‘Ketzerei’ trial)
by
Strauß, Christian
,
Unterberg, Matthias
,
Rosenberger, Peter
in
Acidosis
,
Acute Kidney Injury - therapy
,
Acute renal failure
2025
IntroductionThe only supportive therapy for patients with severe acute kidney injury (AKI), a common complication among the critically ill, is dialysis. Based on the literature and current guidelines, continuous renal replacement therapy (CRRT) with a total effluent dose of 20–25 mL/kg/hour and adjustments to ensure such dose is delivered despite down time (eg, due to surgical procedures) is recommended. However, experimental and clinical studies suggest that azotaemia, which can be induced by lowering the effluent dose, may accelerate renal recovery. This clinical study investigates whether a lower effluent dose (10–15 mL/kg/hour) for a maximum of 7 days or until successful (>24 hours) liberation of CRRT in critically ill patients with a dialysis-dependent AKI accelerates renal recovery and reduces time on CRRT compared with guideline-directed standard dose (25–30 mL/kg/hour).Methods and analysisThe Ketzerei trial is an international, multicentre randomised, controlled trial, designed to investigate if a lower effluent dose (10–15 mL/kg/hour) accelerates renal recovery and reduces the time on CRRT compared with the guideline directed standard effluent dose (25–30 mL/kg/hour). The study aims to enrol 150 critically ill patients with a dialysis-dependent AKI. Eligible patients will be randomised to receive either a standard effluent dose (control group, 25–30 mL/kg/hour) or lower effluent dose (interventional group, 10–15 mL/kg/hour). The primary endpoint is the number of days free from CRRT and alive (from randomisation through day 28). Key secondary endpoints include the number of (serious) adverse events due to potential uremia, the duration of RRT and intensive care unit survival.Ethics and disseminationThe Ketzerei trial has been approved by the Ethics Committee of the Chamber of Physicians Westfalen-Lippe (2023–343 f-s), the University of Muenster and subsequently by the corresponding Ethics Committee of the participating sites. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and will guide patient care and further research.Trial registration numberclinicaltrials.gov (NCT06021288).
Journal Article
Midazolam impacts acetyl—And butyrylcholinesterase genes: An epigenetic explanation for postoperative delirium?
by
Koos, Björn
,
Thon, Patrick
,
Holtkamp, Caroline
in
Acetylcholinesterase
,
Benzodiazepines
,
Biology and life sciences
2022
Midazolam is a widely used short-acting benzodiazepine. However, midazolam is also criticized for its deliriogenic potential. Since delirium is associated with a malfunction of the neurotransmitter acetylcholine, midazolam appears to interfere with its proper metabolism, which can be triggered by epigenetic modifications. Consequently, we tested the hypothesis that midazolam indeed changes the expression and activity of cholinergic genes by acetylcholinesterase assay and qPCR. Furthermore, we investigated the occurrence of changes in the epigenetic landscape by methylation specific PCR, ChiP-Assay and histone ELISA. In an in-vitro model containing SH-SY5Y neuroblastoma cells, U343 glioblastoma cells, and human peripheral blood mononuclear cells, we found that midazolam altered the activity of acetylcholinesterase /buturylcholinesterase (AChE / BChE). Interestingly, the increased expression of the buturylcholinesterase evoked by midazolam was accompanied by a reduced methylation of the BCHE gene and the di-methylation of histone 3 lysine 4 and came along with an increased expression of the lysine specific demethylase KDM1A. Last, inflammatory cytokines were not induced by midazolam. In conclusion, we found a promising mechanistic link between midazolam treatment and delirium, due to a significant disruption in cholinesterase homeostasis. In addition, midazolam seems to provoke profound changes in the epigenetic landscape. Therefore, our results can contribute to a better understanding of the hitherto poorly understood interactions and risk factors of midazolam on delirium.
Journal Article
Association Between Differential Heterogeneity of Antibiotics Consumption and Share of Resistant Pathogens and Its Implication for Antibiotic Stewardship in a German Hospital Intensive Care Unit
by
Timmesfeld, Nina
,
Nowak, Hartmuth
,
Adamzik, Michael
in
Analysis
,
Antibiotic resistance
,
Antibiotics
2025
Background: The rapid rise in antimicrobial resistance has become one of the 10 most pressing health problems worldwide in recent years. Antibiotic stewardship offers hope in the fight against antibiotic resistance, but it is currently still falling short of expectations. A better understanding of the dynamics of the interaction between antibiotic consumption and the emergence and spread of resistance is urgently needed. Methods: We discuss a simple dynamic model based on a differential equation to describe the increase in the proportion of a pathogen’s antimicrobial resistance to an antibiotic as a function of the time-dependent consumption of that antibiotic. Furthermore, we investigate the association of heterogeneity in the consumption of antibiotics with the rate of resistant pathogens. Data basis is the hospital information system and the patient data-management system of a German hospital, restricted to the intensive care unit. To quantify heterogeneity, we discuss and compare different entropy measures. Results: For some pathogen–antibiotic pairs, the consumption-dependent dynamic model for the growth in the proportion of antimicrobial resistance provides acceptable predictions, while for others, the model is less suitable. Cross-resistance and complex interactions with other pathogens and antibiotics may be responsible for this, suggesting that the observed dynamic behavior should be complementary, described using heterogeneity models. Time courses of Shannon entropy, the Antibiotic Heterogeneity Index, and the negative Gini Index correlate positively with the time series of the resistance rate. Thus, an increase in heterogeneity correlates with a decreasing resistance rate. However, a time-delayed cross-correlation of a differential entropy measure with resistance share suggests a functional dependence that can be utilized for antibiotic stewardship. Conclusions: Evidence is provided that the amount of consumption of certain antibiotics drives the corresponding proportions of pathogens’ resistance to these antibiotics; however, the model predictions of these univariable models are generally not sufficiently good, pointing to a more complex interaction dynamics. Therefore, we switch to the level of structural features and show that the degree of constantly mixing of the shares of antibiotic consumption has a control function regarding the incidence of resistance. Controlling differential consumption heterogeneity, therefore, appears to be a feasible operational basis for antibiotic stewardship. Experimental studies are demanded to identify functional dependencies; however, the integration of clinical expertise with model-based prediction appears to be a feasible antibiotic stewardship strategy.
Journal Article
The Actual Clinical Situation Ruthlessly Exposes the Challenge of Rational Care for Nosocomial and Community-Acquired Infections and Requires Even More Efforts for Satisfactory Antibiotic Stewardship
by
Timmesfeld, Nina
,
Wallrafen, A. Melina
,
Nowak, Hartmuth
in
Ampicillin
,
Antibiotic resistance
,
antibiotic stewardship
2025
Background: Antimicrobial resistance is one of the 10 most pressing health problems worldwide. Methods: First steps toward harnessing the complex dynamics of antibiotic resistance are presented. To accomplish this, we first shift down a gear and try to understand the actual driving dynamics behind the development of resistance in a specific clinical department. Analyses are based on the clinical and microbiological data of a German hospital over an observation period of more than 7 years, which we evaluate descriptively and semi-quantitatively in order to obtain a basis for informed and intelligent action in terms of antibiotic stewardship. Results: The specific results include the observed increase in the resistance rate with increasing overall consumption, while increases over time independent of consumption are fairly moderate. Vancocymin and refoximin are an exception in the development of resistance, as resistance to these substances appears to decrease with increasing consumption. However, there have been substantial dose adjustments for these substances, which are likely to be decisive here. An intra-host increase in resistance due to treatment time on the one hand and repeated treatments on the other is observed. Within the sub-cohort of ineffectively treated patients, i.e., with resistance to the antibiotic, mortality increases on average, but with ampicillin/sulbactam as a striking exception. Patients with infections caused by ampicillin-resistant bacteria have a lower mortality rate. The observed resistance rates of the eight most frequently administered antibiotics show a temporal variability that includes random fluctuations as well as decidedly regular cycles. The time series associated with the various antibiotics show pairwise time lag correlations, which indicates the existence of retardedly mediated cross-resistance. Conclusions: We conclude with an outlook on upcoming further analyses and a draft action plan on how to control and harness the complex dynamics observed by means of successful, informed, and intelligent antibiotic stewardship.
Journal Article
Increased circulating microRNA-122 is a biomarker for discrimination and risk stratification in patients defined by sepsis-3 criteria
2018
Sepsis is now operationally defined as life-threatening organ dysfunction caused by an infection, identified by an acute change in SOFA-Score of at least two points, including clinical chemistry such as creatinine or bilirubin concentrations. However, little knowledge exists about organ-specific microRNAs as potentially new biomarkers. Accordingly, we tested the hypotheses that micro-RNA-122, the foremost liver-related micro-RNA (miR), 1) discriminates between sepsis and infection, 2) is an early predictor for mortality, and 3) improves the prognostic value of the SOFA-score.
We analyzed 108 patients with sepsis (infection + increase SOFA-Score ≥2) within the first 24h of ICU admission and as controls 20 patients with infections without sepsis (infection + SOFA-Score ≤1). Total circulating miR was isolated from serum and relative miR-122 expression was measured (using spiked-in cel-miR-54) and associated with 30-day survival.
30-day survival of the sepsis patients was 63%. miR-122 expression was 40-fold higher in non-survivors (p = 0.001) and increased almost 6-fold in survivors (p = 0.013) compared to controls. miR-122 serum-expression discriminated both between sepsis vs. infection (AUC 0.760, sensitivity 58.3%, specificity 95%) and survivors vs. non-survivors (AUC 0.728, sensitivity 42.5%, specificity 94%). Multivariate Cox-regression analysis revealed miR-122 (HR 4.3; 95%-CI 2.0-8.9, p<0.001) as independent prognostic factor for 30-day mortality. Furthermore, the predictive value for 30-day mortality of the SOFA-Score (AUC 0.668) was improved by adding miR-122 (AUC 0.743; net reclassification improvement 0.37, p<0.001; integrated discrimination improvement 0.07, p = 0.007).
Increased miR-122 serum concentration supports the discrimination between infection and sepsis, is an early and independent risk factor for 30-day mortality, and improves the prognostic value of the SOFA-Score, suggesting a potential role for miR-122 in sepsis-related prediction models.
Journal Article
The aquaporin 5 -1364A/C promoter polymorphism impacts on resolution of acute kidney injury in pneumonia evoked ARDS
by
Peters, Jürgen
,
Nowak, Hartmuth
,
Siffert, Winfried
in
Acute kidney failure
,
Acute Kidney Injury - complications
,
Acute Kidney Injury - diagnosis
2018
Aquaporin 5 (AQP5) expression impacts on cellular water transport, renal function but also on key mechanisms of inflammation and immune cell migration that prevail in sepsis and ARDS. Thus, the functionally relevant AQP5 -1364A/C promoter single nucleotide polymorphism could impact on the development and resolution of acute kidney injury (AKI). Accordingly, we tested the hypothesis that the AQP5 promoter -1364A/C polymorphism is associated with AKI in patients suffering from pneumonia evoked ARDS.
This prospective study included 136 adult patients of Caucasian ethnicity with bacterially evoked pneumonia resulting in ARDS. Blood sampling was performed within 24 hours of ICU admission and patients were genotyped for the AQP5 promoter -1364A/C single nucleotide polymorphism. The development of an AKI and the cumulative net fluid balance was described over a 30-day observation period and compared between the AA and AC/CC genotypes, and between survivors and non-survivors.
Incidence of an AKI upon admission did not differ in AA (58%) and AC/CC genotype carriers (60%; p = 0.791). However, on day 30, homozygous AA genotypes (57%) showed an increased prevalence of AKI compared to AC/CC genotypes (24%; p = 0.001). Furthermore, the AA genotype proved to be a strong, independent risk factor for predicting AKI persistence (odds-ratio: 3.35; 95%-CI: 1.2-9.0; p = 0.017). While a negative cumulative fluid balance was associated with increased survival (p = 0.001) the AQP5 promoter polymorphism had no impact on net fluid balance (p = 0.96).
In pneumonia evoked ARDS, the AA genotype of the AQP5 promoter polymorphism is associated with a decreased recovery rate from AKI and this is independent of fluid balance. Consequently, the role of AQP5 in influencing AKI likely rests in factors other than fluid balance.
Journal Article