Incidence, diagnosis, management and outcome of acute mesenteric ischaemia: a prospective, multicentre observational study (AMESI Study).

BACKGROUND: The aim of this multicentre prospective observational study was to identify the incidence, patient characteristics, diagnostic pathway, management and outcome of acute mesenteric ischaemia (AMI). METHODS: All adult patients with clinical suspicion of AMI admitted or transferred to 32 participating hospitals from 06.06.2022 to 05.04.2023 were included. Participants who were subsequently shown not to have AMI or had localized intestinal gangrene due to strangulating bowel obstruction had only baseline and outcome data collected. RESULTS: AMI occurred in 0.038% of adult admissions in participating acute care hospitals worldwide. From a total of 705 included patients, 418 patients had confirmed AMI. In 69% AMI was the primary reason for admission, while in 31% AMI occurred after having been admitted with another diagnosis. Median time from onset of symptoms to hospital admission in patients admitted due to AMI was 24 h (interquartile range 9-48h) and time from admission to diagnosis was 6h (1-12 h). Occlusive arterial AMI was diagnosed in 231 (55.3%), venous in 73 (17.5%), non-occlusive (NOMI) in 55 (13.2%), other type in 11 (2.6%) and the subtype could not be classified in 48 (11.5%) patients. Surgery was the initial management in 242 (58%) patients, of which 59 (24.4%) underwent revascularization. Endovascular revascularization alone was carried out in 54 (13%), conservative treatment in 76 (18%) and palliative care in 46 (11%) patients. From patients with occlusive arterial AMI, revascularization was undertaken in 104 (45%), with 40 (38%) of them in one site admitting selected patients. Overall in-hospital and 90-day mortality of AMI was 49% and 53.3%, respectively, and among subtypes was lowest for venous AMI (13.7% and 16.4%) and highest for NOMI (72.7% and 74.5%). There was a high variability between participating sites for most variables studied. CONCLUSIONS: The overall incidence of AMI and AMI subtypes varies worldwide, and case ascertainment is challenging. Pre-hospital delay in presentation was greater than delays after arriving at hospital. Surgery without revascularization was the most common management approach. Nearly half of the patients with AMI died during their index hospitalization. Together, these findings suggest a need for greater awareness of AMI, and better guidance in diagnosis and management. TRIAL REGISTRATION: NCT05218863 (registered 19.01.2022).

Pressure- and time-dependent alveolar recruitment/derecruitment in a spatially resolved patient-specific computational model for injured human lungs.

We present a novel computational model for the dynamics of alveolar recruitment/derecruitment (RD), which reproduces the underlying characteristics typically observed in injured lungs. The basic idea is a pressure- and time-dependent variation of the stress-free reference volume in reduced dimensional viscoelastic elements representing the acinar tissue. We choose a variable reference volume triggered by critical opening and closing pressures in a time-dependent manner from a straightforward mechanical point of view. In the case of (partially and progressively) collapsing alveolar structures, the volume available for expansion during breathing reduces and vice versa, eventually enabling consideration of alveolar collapse and reopening in our model. We further introduce a method for patient-specific determination of the underlying critical parameters of the new alveolar RD dynamics when integrated into the tissue elements, referred to as terminal units, of a spatially resolved physics-based lung model that simulates the human respiratory system in an anatomically correct manner. Relevant patient-specific parameters of the terminal units are herein determined based on medical image data and the macromechanical behavior of the lung during artificial ventilation. We test the whole modeling approach for a real-life scenario by applying it to the clinical data of a mechanically ventilated patient. The generated lung model is capable of reproducing clinical measurements such as tidal volume and pleural pressure during various ventilation maneuvers. We conclude that this new model is an important step toward personalized treatment of ARDS patients by considering potentially harmful mechanisms-such as cyclic RD and overdistension-and might help in the development of relevant protective ventilation strategies to reduce ventilator-induced lung injury (VILI).

What the clinician needs to know about medical nutrition therapy in critically ill patients in 2023: A narrative review.

Medical nutrition therapy (MNT) represents an essential element in the medical care of critically ill patients admitted to an intensive care unit (ICU). Increasing awareness exists that energy and nutrients not only preserve body structures such as lean body/muscle mass but also represent promising therapeutic elements to target the profound metabolic, inflammatory, endocrinologic, and immunologic alterations occurring during critical illness. However, despite intense research activities for years, diverse aspects of MNT such as the optimal timing, dosing, and composition of energy and macronutrient supply, as well as the role of micronutrients, are still an issue of debate resulting from strong heterogeneity in methods and findings of respective studies. These discrepancies are also reflected in diverging recommendations of international clinical nutrition guidelines for specific topics. In addition, implementing targeted, personalized MNT strategies in routine clinical practice underlies difficulties and challenges resulting from disease-specific issues and/or organizational, structural, and educational aspects. This narrative review aims to summarize the most recent evidence relevant to clinical practice on selected aspects of MNT in adult patients in the ICU and to provide guidance for implementing evidence-based approaches for adequate energy and nutrient supply in the ICU setting.

Current practices in nutrition therapy in cardiac surgery patients: An international multicenter observational study.

BACKGROUND: Cardiac surgery patients with a prolonged stay in the intensive care unit (ICU) are at high risk for acquired malnutrition. Medical nutrition therapy practices for cardiac surgery patients are unknown. The objective of this study is to describe the current nutrition practices in critically ill cardiac surgery patients worldwide. METHODS: We conducted a prospective observational study in 13 international ICUs involving mechanically ventilated cardiac surgery patients with an ICU stay of at least 72 h. Collected data included the energy and protein prescription, type of and time to the initiation of nutrition, and actual quantity of energy and protein delivered (maximum: 12 days). RESULTS: Among 237 enrolled patients, enteral nutrition (EN) was started, on average, 45 h after ICU admission (range, 0-277 h; site average, 53 [range, 10-79 h]). EN was prescribed for 187 (79%) patients and combined EN and parenteral nutrition in 33 (14%). Overall, patients received 44.2% (0.0%-117.2%) of the prescribed energy and 39.7% (0.0%-122.8%) of the prescribed protein. At a site level, the average nutrition adequacy was 47.5% (30.5%-78.6%) for energy and 43.6% (21.7%-76.6%) for protein received from all nutrition sources. CONCLUSION: Critically ill cardiac surgery patients with prolonged ICU stay experience significant delays in starting EN and receive low levels of energy and protein. There exists tremendous variability in site performance, whereas achieving optimal nutrition performance is doable.

Current practice of gastric residual volume measurements and related outcomes of critically ill patients: A secondary analysis of the intestinal-specific organ function assessment study.

BACKGROUND: Gastric residual volume (GRV) measurement to detect gastrointestinal (GI) dysfunction is a common diagnostic procedures in critical care, albeit still not well standardized being operator-, patient-, and tube-dependent. Our aim was to describe current practice of GRV measurements and its association with clinical outcomes in critically ill patients. METHODS: This was a secondary analysis of an international prospective observational cohort study (intestinal-specific organ function assessment). Eligibility criteria were defined as ≥1 GRV measurement during the 7-day study period. Data collection included GRV measurement practices, tube diameters and volumes, symptoms of GI dysfunction, and clinical outcomes. The primary aim was to describe current practices of GRV measurements, and the secondary aim was to test the association of high (>200 ml) vs. low GRV with symptoms of GI dysfunction and clinical outcomes using generalized linear regression and survival models. RESULTS: Two hundred fifty-eight patients with 2422 GRV measurements on 875 study days were analyzed. GRV was mainly measured via passive drainage twice daily using large diameter tubes. There was no significant association between tube size or measurement technique and high GRV. High GRV occurred in 34% of patients and was associated with other GI symptoms and with increased disease severity but not with 28-day or 90-day mortality, intensive care unit-free and ventilator-free days. CONCLUSION: There was substantial variability of GRV measurement techniques, but this had no impact on the amount of GRV. High GRV was not associated with mortality or ventilator-free days but may serve as a marker of GI dysfunction and disease severity.

[Bacterial gut microbiota-key player in sepsis]. / Das bakterielle intestinale Mikrobiom ­ Key Player in der Sepsis.

The gut microbiota is comprised of over 1200 different bacteria and forms a symbiotic community with the human organism, the holobiont. It plays an important role in the maintenance of homeostasis, e.g., of the immune system and essential metabolic processes. Disturbances in the balance of this reciprocal relationship are called dysbiosis and, in the field of sepsis, are associated with incidence of disease, extent of the systemic inflammatory response, severity of organ dysfunction, and mortality. In addition to providing guiding principles in the fascinating relationship between "human and microbe," this article summarizes recent findings regarding the role of the bacterial gut microbiota in sepsis, which is one a very relevant in intensive care medicine.

Resting Energy Expenditure in the Critically Ill and Healthy Elderly-A Retrospective Matched Cohort Study.

The use of indirect calorimetry to measure resting energy expenditure (mREE) is widely recommended as opposed to calculating REE (cREE) by predictive equations (PE). The aim of this study was to compare mREE with cREE in critically ill, mechanically ventilated patients aged ≥ 75 years and a healthy control group matched by age, gender and body mass index. The primary outcome was the PE accuracy rate of mREE/cREE, derived using Bland Altman plots. Secondary analyses included linear regression analyses for determinants of intraindividual mREE/cREE differences in the critically ill and interindividual mREE differences in the matched healthy cohort. In this retrospective study, 90 critically ill patients (median age 80 years) and 58 matched healthy persons were included. Median mREE was significantly higher in the critically ill (1457 kcal/d) versus the healthy cohort (1351 kcal/d), with low PE accuracy rates (21% to 49%). Independent predictors of mREE/cREE differences in the critically ill were body temperature, heart rate, FiO2, hematocrit, serum sodium and urea. Body temperature, respiratory rate, and FiO2 were independent predictors of interindividual mREE differences (critically ill versus healthy control). In conclusion, the commonly used PE in the elderly critically ill are inaccurate. Respiratory, metabolic and energy homeostasis variables may explain intraindividual mREE/cREE as well as interindividual mREE differences.

Medical nutrition therapy in patients receiving ECMO: Evidence-based guidance for clinical practice.

Patients receiving extracorporeal membrane oxygenation (ECMO) inherit substantial disease-associated metabolic, endocrinologic, and immunologic modifications. Along with the technical components of ECMO, the aforementioned alterations may affect patients' needs and feasibility of adequate macronutrient and micronutrient supply and intake. Thus, patients receiving ECMO are at increased risk for iatrogenic malnutrition and require targeted individual medical nutrition therapy (MNT). However, specific recommendations for MNT in patients receiving ECMO are limited and, with some exceptions, based on an evidence base encompassing general patients who are critically ill. Consequently, clinician decision-making for MNT in patients receiving ECMO is unguided, which may further increase nutrition risk, culminating in iatrogenic malnutrition and ultimately affecting patient outcomes. The purpose of this article is to provide educational background and highlight specific points for MNT in adult patients receiving ECMO, which might serve as evidence-based guidance to develop institutional standard operating procedures and nutrition protocols for daily clinical practice.

Epidemiology and age-related mortality in critically ill patients with intra-abdominal infection or sepsis: an international cohort study.

OBJECTIVE: To describe epidemiology and age-related mortality in critically ill older adults with intra-abdominal infection. METHODS: A secondary analysis was undertaken of a prospective, multi-national, observational study (Abdominal Sepsis Study, ClinicalTrials.gov #NCT03270345) including patients with intra-abdominal infection from 309 intensive care units (ICUs) in 42 countries between January and December 2016. Mortality was considered as ICU mortality, with a minimum of 28 days of observation when patients were discharged earlier. Relationships with mortality were assessed by logistic regression analysis. RESULTS: The cohort included 2337 patients. Four age groups were defined: middle-aged patients [reference category; 40-59 years; n=659 (28.2%)], young-old patients [60-69 years; n=622 (26.6%)], middle-old patients [70-79 years; n=667 (28.5%)] and very old patients [≥80 years; n=389 (16.6%)]. Secondary peritonitis was the predominant infection (68.7%) and was equally prevalent across age groups. Mortality increased with age: 20.9% in middle-aged patients, 30.5% in young-old patients, 31.2% in middle-old patients, and 44.7% in very old patients (P<0.001). Compared with middle-aged patients, young-old age [odds ratio (OR) 1.62, 95% confidence interval (CI) 1.21-2.17], middle-old age (OR 1.80, 95% CI 1.35-2.41) and very old age (OR 3.69, 95% CI 2.66-5.12) were independently associated with mortality. Other independent risk factors for mortality included late-onset hospital-acquired intra-abdominal infection, diffuse peritonitis, sepsis/septic shock, source control failure, liver disease, congestive heart failure, diabetes and malnutrition. CONCLUSIONS: For ICU patients with intra-abdominal infection, age >60 years was associated with mortality; patients aged ≥80 years had the worst prognosis. Comorbidities and overall disease severity further compromised survival. As all of these factors are non-modifiable, it remains unclear how to improve outcomes.

A multifaceted educational intervention improved anti-infectious measures but had no effect on mortality in patients with severe sepsis.

Sepsis is a major reason for preventable hospital deaths. A cluster-randomized controlled trial on an educational intervention did not show improvements of sepsis management or outcome. We now aimed to test an improved implementation strategy in a second intervention phase in which new intervention hospitals (former controls) received a multifaceted educational intervention, while controls (former intervention hospitals) only received feedback of quality indicators. Changes in outcomes from the first to the second intervention phase were compared between groups using hierarchical generalized linear models controlling for possible confounders. During the two phases, 19 control hospitals included 4050 patients with sepsis and 21 intervention hospitals included 2526 patients. 28-day mortality did not show significant changes between study phases in both groups. The proportion of patients receiving antimicrobial therapy within one hour increased in intervention hospitals, but not in control hospitals. Taking at least two sets of blood cultures increased significantly in both groups. During phase 2, intervention hospitals showed higher proportion of adequate initial antimicrobial therapy and de-escalation within 5 days. A survey among involved clinicians indicated lacking resources for quality improvement. Therefore, quality improvement programs should include all elements of sepsis guidelines and provide hospitals with sufficient resources for quality improvement.Trial registration: ClinicalTrials.gov, NCT01187134. Registered 23 August 2010, https://www.clinicaltrials.gov/ct2/show/study/NCT01187134 .

Adverse effects of delayed antimicrobial treatment and surgical source control in adults with sepsis: results of a planned secondary analysis of a cluster-randomized controlled trial.

BACKGROUND: Timely antimicrobial treatment and source control are strongly recommended by sepsis guidelines, however, their impact on clinical outcomes is uncertain. METHODS: We performed a planned secondary analysis of a cluster-randomized trial conducted from July 2011 to May 2015 including forty German hospitals. All adult patients with sepsis treated in the participating ICUs were included. Primary exposures were timing of antimicrobial therapy and delay of surgical source control during the first 48 h after sepsis onset. Primary endpoint was 28-day mortality. Mixed models were used to investigate the effects of timing while adjusting for confounders. The linearity of the effect was investigated by fractional polynomials and by categorizing of timing. RESULTS: Analyses were based on 4792 patients receiving antimicrobial treatment and 1595 patients undergoing surgical source control. Fractional polynomial analysis identified a linear effect of timing of antimicrobials on 28-day mortality, which increased by 0.42% per hour delay (OR with 95% CI 1.019 [1.01, 1.028], p ≤ 0.001). This effect was significant in patients with and without shock (OR = 1.018 [1.008, 1.029] and 1.026 [1.01, 1.043], respectively). Using a categorized timing variable, there were no significant differences comparing treatment within 1 h versus 1-3 h, or 1 h versus 3-6 h. Delays of more than 6 h significantly increased mortality (OR = 1.41 [1.17, 1.69]). Delay in antimicrobials also increased risk of progression from severe sepsis to septic shock (OR per hour: 1.051 [1.022, 1.081], p ≤ 0.001). Time to surgical source control was significantly associated with decreased odds of successful source control (OR = 0.982 [0.971, 0.994], p = 0.003) and increased odds of death (OR = 1.011 [1.001, 1.021]; p = 0.03) in unadjusted analysis, but not when adjusted for confounders (OR = 0.991 [0.978, 1.005] and OR = 1.008 [0.997, 1.02], respectively). Only, among patients with septic shock delay of source control was significantly related to risk-of death (adjusted OR = 1.013 [1.001, 1.026], p = 0.04). CONCLUSIONS: Our findings suggest that management of sepsis is time critical both for antimicrobial therapy and source control. Also patients, who are not yet in septic shock, profit from early anti-infective treatment since it can prevent further deterioration. Trial registration ClinicalTrials.gov ( NCT01187134 ). Registered 23 August 2010, NCT01187134.

A Robust Miniaturized Gas Sensor for H2 and CO2 Detection Based on the 3ω Method.

Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62% in the case of CO2, and only 0.062% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors.

Mobilization in the evening to prevent delirium: A pilot randomized trial.

BACKGROUND: Delirium is a common complication in patients in Intensive Care Units (ICU). Interventions such as mobilization are effective in the prevention and treatment of delirium, although this is usually completed during the daytime. AIM: The aim of this study was to assess the feasibility of mobilization in the evening to prevent and treat ICU patients from delirium by an additional mobility team over 2 weeks. METHODS: The design was a pilot, multi-centre, randomized, controlled trial in four mixed ICUs over a period of 2 weeks. The mobility team consisted of trained nurses and physiotherapists. Patients in the intervention group were mobilized onto the edge of the bed or more between 21.00 and 23.00. Patients in the control group received usual care. The primary outcome parameter was the feasibility of the study, measured as recruitment rate, delivery rate, and safety. Secondary outcomes were duration and incidence of delirium, mortality, duration of mechanical ventilation (MV), and hospital length of stay for 28 days follow-up, and power calculation for a full trial. RESULTS: Out of 185 patients present in the ICUs, 28.6% (n = 53) were eligible and could be recruited, of which 24.9% (n = 46, Intervention = 26, Control = 20) were included in the final analysis. In the intervention group, mobilization could be delivered in 75% (n = 54) of 72 possible occasions; mobilization-related safety events appeared in 16.7% (n = 9) without serious consequences. Secondary parameters were similar, with less delirium in the intervention group albeit not significant. With an association of Cramer's V = 0.237, a complete study reaching statistical significance would require at least 140 patients, last 6 weeks, and cost >30 000 €. CONCLUSIONS: In a mixed ICU population, mobilization in the evening was feasible in one-quarter of patients with a low rate of safety events. Future trials seem to be feasible and worth conducting.

Effects of remote ischemic preconditioning (RIPC) and chronic remote ischemic preconditioning (cRIPC) on levels of plasma cytokines, cell surface characteristics of monocytes and in-vitro angiogenesis: a pilot study.

Remote ischemic preconditioning (RIPC) protects the heart against myocardial ischemia/reperfusion (I/R) injury and recent work also suggested chronic remote ischemic conditioning (cRIPC) for cardiovascular protection. Based on current knowledge that systemic immunomodulatory effects of RIPC and the anti-inflammatory capacity of monocytes might be involved in cardiovascular protection, the aim of our study was to evaluate whether RIPC/cRIPC blood plasma is able to induce in-vitro angiogenesis, identify responsible factors and evaluate the effects of RIPC/cRIPC on cell surface characteristics of circulating monocytes. Eleven healthy volunteers were subjected to RIPC/cRIPC using a blood pressure cuff inflated to > 200 mmHg for 3 × 5 min on the upper arm. Plasma and peripheral blood monocytes were isolated before RIPC (Control), after 1 × RIPC (RIPC) and at the end of 1 week of daily RIPC (cRIPC) treatment. Plasma concentrations of potentially pro-angiogenic humoral factors (CXCL5, Growth hormone, IGFBP3, IL-1α, IL-6, Angiopoietin 2, VEGF, PECAM-1, sTie-2, IL-8, MCSF) were measured using custom made multiplex ELISA systems. Tube formation assays for evaluation of in-vitro angiogenesis were performed with donor plasma, monocyte conditioned culture media as well as IL-1α, CXCL5 and Growth hormone. The presence of CD14, CD16, Tie-2 and CCR2 was analyzed on monocytes by flow cytometry. Employing in-vitro tube formation assays, several parameters of angiogenesis were significantly increased by cRIPC plasma (number of nodes, P < 0.05; number of master junctions, P < 0.05; number of segments, P < 0.05) but were not influenced by culture medium from RIPC/cRIPC treated monocytes. While RIPC/cRIPC treatment did not lead to significant changes of the median plasma concentrations of any of the selected potentially pro-angiogenic humoral factors, in-depth analysis of the individual subjects revealed differences in plasma levels of IL-1α, CXCL5 and Growth hormone after RIPC/cRIPC treatment in some of the volunteers. Nevertheless, the positive effects of RIPC/cRIPC plasma on in-vitro angiogenesis could not be mimicked by the addition of the respective humoral factors alone or in combination. While monocyte conditioned culture media did not affect in-vitro tube formation, flow cytometry analyses of circulating monocytes revealed a significant increase in the number of Tie-2 positive and a decrease of CCR2 positive monocytes after RIPC/cRIPC (Tie-2: cRIPC, P < 0.05; CCR2: RIPC P < 0.01). Cardiovascular protection may be mediated by RIPC and cRIPC via a regulation of plasma cytokines as well as changes in cell surface characteristics of monocytes (e.g. Tie-2). Our results suggest that a combination of humoral and cellular factors could be responsible for the RIPC/cRIPC mediated effects and that interindividual variations seem to play a considerable part in the RIPC/cRIPC associated mechanisms.

Fever and hypothermia represent two populations of sepsis patients and are associated with outside temperature.

BACKGROUND: Fever and hypothermia have been observed in septic patients. Their influence on prognosis is subject to ongoing debates. METHODS: We did a secondary analysis of a large clinical dataset from a quality improvement trial. A binary logistic regression model was calculated to assess the association of the thermal response with outcome and a multinomial regression model to assess factors associated with fever or hypothermia. RESULTS: With 6542 analyzable cases we observed a bimodal temperature response characterized by fever or hypothermia, normothermia was rare. Hypothermia and high fever were both associated with higher lactate values. Hypothermia was associated with higher mortality, but this association was reduced after adjustment for other risk factors. Age, community-acquired sepsis, lower BMI and lower outside temperatures were associated with hypothermia while bacteremia and higher procalcitonin values were associated with high fever. CONCLUSIONS: Septic patients show either a hypothermic or a fever response. Whether hypothermia is a maladaptive response, as indicated by the higher mortality in hypothermic patients, or an adaptive response in patients with limited metabolic reserves under colder environmental conditions, remains an open question. Trial registration The original trial whose dataset was analyzed was registered at ClinicalTrials.gov (NCT01187134) on August 23, 2010, the first patient was included on July 1, 2011.

Video-based, student tutor- versus faculty staff-led ultrasound course for medical students - a prospective randomized study.

BACKGROUND: Ultrasound education is propagated already during medical school due to its diagnostic importance. Courses are usually supervised by experienced faculty staff (FS) with patient bedside examinations or students among each other but often overbooked due to limited FS availability. To overcome this barrier, use of teaching videos may be advantageous. Likewise, peer teaching concepts solely with trained student tutors have shown to be feasible and effective. The aim was to evaluate 1) objective learning outcomes of a combined video-based, student-tutor (ViST) as compared to a FS-led course without media support, 2) acceptance and subjective learning success of the videos. METHODS: Two ultrasound teaching videos for basic and advanced abdominal ultrasound (AU) and transthoracic echocardiography (TTE) were produced and six students trained as tutors. Fourth-year medical students (N = 96) were randomized to either the ViST- or FS course (6 students per tutor). Learning objectives were defined equally for both courses. Acquired practical basic and advanced ultrasound skills were tested in an objective structured clinical examination (OSCE) using modified validated scoring sheets with a maximum total score of 40 points. Acceptance and subjective learning success of both videos were evaluated by questionnaires based on Kirkpatrick's evaluation model with scale-rated closed and open questions. RESULTS: 79 of 96 medical students completed the OSCE and 77 could be finally analyzed. There was no significant difference in the mean total point score of 31.3 in the ViST (N = 42) and 32.7 in the FS course (N = 35, P = 0.31) or in any of the examined basic or advanced ultrasound skill subtasks. Of the 42 ViST participants, 29 completed the AU and 27 the TTE video questionnaire. Acceptance and subjective learning success of both videos was rated positively in 14-52% and 48-88% of the rated responses to each category, respectively. Attendance of either the student or faculty tutor was deemed necessary in addition to the videos. CONCLUSIONS: A ViST versus FS teaching concept was able to effectively teach undergraduate students in AU and TTE, albeit acceptance of the teaching videos alone was limited. However, the ViST concept has the potential to increase course availability and FS resource allocation.

Longitudinal Multi-omics Analyses Identify Responses of Megakaryocytes, Erythroid Cells, and Plasmablasts as Hallmarks of Severe COVID-19.

Temporal resolution of cellular features associated with a severe COVID-19 disease trajectory is needed for understanding skewed immune responses and defining predictors of outcome. Here, we performed a longitudinal multi-omics study using a two-center cohort of 14 patients. We analyzed the bulk transcriptome, bulk DNA methylome, and single-cell transcriptome (>358,000 cells, including BCR profiles) of peripheral blood samples harvested from up to 5 time points. Validation was performed in two independent cohorts of COVID-19 patients. Severe COVID-19 was characterized by an increase of proliferating, metabolically hyperactive plasmablasts. Coinciding with critical illness, we also identified an expansion of interferon-activated circulating megakaryocytes and increased erythropoiesis with features of hypoxic signaling. Megakaryocyte- and erythroid-cell-derived co-expression modules were predictive of fatal disease outcome. The study demonstrates broad cellular effects of SARS-CoV-2 infection beyond adaptive immune cells and provides an entry point toward developing biomarkers and targeted treatments of patients with COVID-19.

CXCR3 mediates renal Th1 and Th17 immune response in murine lupus nephritis.

Infiltration of T cells into the kidney is a typical feature of human and experimental lupus nephritis that contributes to renal tissue injury. The chemokine receptor CXCR3 is highly expressed on Th1 cells and is supposed to be crucial for their trafficking into inflamed tissues. In this study, we explored the functional role of CXCR3 using the MRL/MpJ-Fas(lpr) (MRL/lpr) mouse model of systemic lupus erythematosus that closely resembles the human disease. CXCR3(-/-) mice were generated and backcrossed into the MRL/lpr background. Analysis of 20-wk-old CXCR3(-/-) MRL/lpr mice showed amelioration of nephritis with reduced glomerular tissue damage and decreased albuminuria and T cell recruitment. Most importantly, not only the numbers of renal IFN-gamma-producing Th1 cells, but also of IL-17-producing Th17 cells were significantly reduced. Unlike in inflamed kidneys, there was no reduction in the numbers of IFN-gamma- or IL-17-producing T cells in spleens, lymph nodes, or the small intestine of MRL/lpr CXCR3(-/-) mice. This observation suggests impaired trafficking of effector T cells to injured target organs, rather than the inability of CXCR3(-/-) mice to mount efficient Th1 and Th17 immune responses. These findings show a crucial role for CXCR3 in the development of experimental lupus nephritis by directing pathogenic effector T cells into the kidney. For the first time, we demonstrate a beneficial effect of CXCR3 deficiency through attenuation of both the Th1 and the newly defined Th17 immune response. Our data therefore identify the chemokine receptor CXCR3 as a promising therapeutic target in lupus nephritis.

Antigen loading of dendritic cells with apoptotic tumor cell-preparations is superior to that using necrotic cells or tumor lysates.

BACKGROUND: Loading of dendritic cells (DCs) with tumor cell (TC) preparations is an attractive method for vaccine preparation because the entire antigen repertoire of a tumor is processed and presented by the DCs, thus allowing the simultaneous stimulation of T-helper cells and cytotoxic T-lymphocytes. However, optimal loading conditions have still to be defined. MATERIALS AND METHODS: DCs were pulsed either with tumor lysates, apoptotic or necrotic preparations of a breast cancer cell line and subsequently used to stimulate autologous T-lymphocytes. Antigen loading was quantified using immunofluorescent-based methods. RESULTS: Four hours co-incubation of apoptotic TCs or tumor lysates with DCs undergoing maturation resulted in effective DC-loading. However, the DCs pulsed with apoptotic TCs were best in stimulating interferon-gamma (INF-gamma) secretion as the effector function of autologous T-cells. CONCLUSION: Tumor lysates are in common use for DC-based vaccine manufacturing. However, our data indicate an advantage of apoptotic TC-preparations in regard to antigen loading effectiveness as well as the loaded DC's capacity to activate T-cells.

Paclitaxel treatment of breast cancer cell lines modulates Fas/Fas ligand expression and induces apoptosis which can be inhibited through the CD40 receptor.

OBJECTIVE: Cytotoxic chemotherapy of advanced breast cancer is frequently complicated by drug resistance. Our goal was to define the role of the apoptosis-regulating receptors Fas (CD95) and CD40 in the chemosensitivity of breast cancer. METHODS: The sensitivity of four breast cancer cell lines to paclitaxel and mitoxantrone was evaluated using an ATP-based cell viability assay. After verification of apoptosis by annexin V staining and TUNEL assay, cell lines were characterized regarding their constitutive expression of both surface and soluble (s)Fas (CD95) and Fas ligand (Fas-L). The role of the Fas/Fas-L system and different caspases was assessed by blocking drug-mediated apoptosis with specific antibodies. Finally, the paclitaxel sensitivity of the CD40-negative cell line KS was compared to that of its CD40-positive transfectant KS-CD40. RESULTS AND CONCLUSION: While the cytotoxic effect of mitoxantrone did not correlate with Fas expression, the results presented here suggest some involvement of the Fas/Fas-L system in paclitaxel-induced apoptosis. Cell lines with constitutive expression of Fas/sFas demonstrated a higher sensitivity to paclitaxel than Fas-negative cells. Incubation with paclitaxel led to a measurable downregulation of the expression of both soluble and surface Fas receptor in these cells. Interestingly, stimulation of the CD40 receptor inhibited paclitaxel-induced apoptosis in the transfected cell line KS-CD40, suggesting a role of this receptor in the modulation of chemosensitivity.