NLRP6 Inflammasome Modulates Disease Progression in a Chronic-Plus-Binge Mouse Model of Alcoholic Liver Disease.

A considerable percentage of the population is affected by alcoholic liver disease (ALD). It is characterized by inflammatory signals from the liver and other organs, such as the intestine. The NLR family pyrin domain containing 6 (NLRP6) inflammasome complex is one of the most important inflammatory mediators. The aim of this study was to evaluate a novel mouse model for ALD characterized by 8-week chronic-plus-binge ethanol administration and to investigate the role of NLRP6 inflammasome for intestinal homeostasis and ALD progression using Nlrp6-/- mice. We showed that chronic-plus-binge ethanol administration triggers hepatic steatosis, injury, and neutrophil infiltration. Furthermore, we discovered significant changes of intestinal microbial communities, including increased relative abundances of bacteria within the phyla Bacteroidota and Campilobacterota, as well as reduced Firmicutes. In this ALD model, inhibiting NLRP6 signaling had no effect on liver steatosis or damage, but had a minor impact on intestinal homeostasis via affecting intestinal epithelium function and gut microbiota. Surprisingly, Nlrp6 loss resulted in significantly decreased hepatic immune cell infiltration. As a result, our novel mouse model encompasses several aspects of human ALD, such as intestinal dysbiosis. Interfering with NLRP6 inflammasome activity reduced hepatic immune cell recruitment, indicating a disease-aggravating role of NLRP6 during ALD.

Acceptance of SARS-CoV-2 vaccines by liver transplant recipients and candidates.

Guidelines recommend vaccination against SARS-CoV-2 in transplant recipients, candidates, and their household contacts. However, little is known about the acceptance of COVID-19 vaccines in these groups.In March 2021, we surveyed 826 liver transplant recipients, candidates, and their household contacts to determine acceptance rates and factors influencing the acceptance of the COVID-19 vaccine; 341 patients (40%) and 237 household contacts (28%) returned the questionnaire. Ninety percent of patients returning the survey reported they were willing to receive the vaccine within the next 6 months or had already started vaccination. Only 2% of patients and 4% of household contacts reported refusing the vaccine, and 8% of patients and 9% of household contacts wanted to postpone vaccination because of concerns about side effects. Having received the influenza vaccine in the last 2 seasons was the strongest indicator of acceptance to receive the SARS-CoV-2 vaccine within 6 months (odds ratio 5.11; 95% confidence interval 2.43-10.74; p < 0.001). Thirty-two percent of responding patients reported fear of side effects as a reason for having refused vaccination before.Although the acceptance of the SARS-CoV-2 vaccine was particularly high among German liver transplant recipients, candidates, and household contacts in this survey, transplant physicians are encouraged to discuss safety concerns with patients who have refused the seasonal influenza vaccine in the past.

Between fear and courage: Attitudes, beliefs, and behavior of liver transplantation recipients and waiting list candidates during the COVID-19 pandemic.

Patients with chronic liver disease and patients after solid organ transplantation (SOT) are vulnerable to severe coronavirus disease 2019 (COVID-19). We evaluated fears, attitudes, and opinions associated with COVID-19 in 365 SOT recipients (95% liver, 5% pancreas/kidney), 112 SOT candidates, and 394 immediate household contacts in 2 German transplant centers. Seven (1.5%) patients and 10 (2.5%) controls had contact with confirmed COVID-19 cases. Fear of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was expressed by 65% of SOT recipients and by 55% of SOT candidates. SOT recipients had higher levels of fear of infection and more often wore personal protective gear than household controls. Female sex, steroid treatment, and using the local newspaper as a primary source of information were independently associated with expressed fear of infection in SOT recipients. Younger age and more recent transplantation correlated with concerns about severe COVID-19 expressed by patients and with concerns about worse medical care expressed by household controls. One third of the patients expressed fear that immunosuppression could worsen COVID-19 but only 15% used the transplantation center as a source of information. These data show that fears associated with the SARS-CoV-2 pandemic are frequently expressed but measures to prevent infection are regularly followed by patients before and after SOT.

Successful Fecal Microbiota Transplantation in a Patient with Severe Complicated Clostridium difficile Infection after Liver Transplantation.

Clostridium difficile infection (CDI) represents one of the most common healthcare-associated infections. Due to increasing numbers of recurrences and therapy failures, CDI has become a major disease burden. Studies have shown that fecal microbiota transplantation (FMT) can both be a safe and highly efficacious therapy for patients with therapy-refractory CDI. However, patients undergoing solid organ transplantation are at high risk for CDI due to long-term immunosuppression, previous antibiotic therapy, and proton pump inhibitor use. Additionally, these patients may be especially prone to adverse events related to FMT. Here, we report a successful FMT in a patient with severe therapy-refractory CDI after liver transplantation.

Spraying Respiratory Epithelial Cells to Coat Tissue-Engineered Constructs.

Applying cells in a spray can overcome current hurdles in coating tissue engineered constructs with a thin layer of endo- or epithelial cells. We report here a structured study on the influences of spray application with a medical spray device on vascular smooth muscle cells (vSMCs) and respiratory epithelial cells (RECs) with and without fibrin gel. Next to viability and cytotoxicity assays, the in vitro differentiation capacity after spray processing was analyzed. For vSMC, no influence of air pressures till 0.8 bar could be shown, whereas the viability decreased for higher pressures. The viability of RECs was reduced to 88.5% with 0.4 bar air pressure. Lactate dehydrogenase-levels in the culture medium increased the first day after spraying but normalized afterward. In the short term, no differences by means of morphology and expression-specific markers for vSMCs and RECs were seen between the control and study group. In addition, in a long-term study for 28 days with the air-liquid interface, RECs differentiated and built up an organized epithelial layer with ciliary development that was comparable to the control for cells sprayed without fibrin gel. When spraying within fibrin gel, ciliary development was lower at 28 days. Thus, spraying of vSMCs and RECs was proved to be a suitable method for tissue engineering. Especially for RECs, this application is of special significance when coating luminal structures or other unfavorable topographies.

Differentiation of respiratory epithelium in a 3-dimensional co-culture with fibroblasts embedded in fibrin gel.

BACKGROUND: Tracheal tissue engineering is a promising option for the treatment of tracheal defects. In a previous study we proved the suitability of fibrin gel as a scaffold for tracheal tissue engineering. This study investigates whether the differentiation of respiratory epithelium can be increased by culturing epithelial cells in a three dimensional system containing fibroblasts embedded into fibrin gel. METHODS: Respiratory epithelial cells were isolated from porcine trachea, seeded onto a fibrin gel and kept in air-liquid-interface culture for 33 days. Morphology as well as pan-cytokeratin, MUC5AC and claudin-1 expression of cells cultured on pure fibrin gel were compared to culture on gels containing fibroblasts. RESULTS: After two weeks, cells seeded on pure fibrin gel were multilayered, showed hyperproliferation and dedifferentiation. Co-cultured cells built up a pseudostratified epithelium. The differentiation and organization of epithelial structure improved with respect to time. After four weeks, morphology of the co-cultured respiratory epithelium resembled native tracheal epithelium. Immunohistochemistry showed that respiratory epithelium co-cultured with fibroblasts had an increasing similarity of pan-cytokeratin expression compared to native trachea. Cells cultured without fibroblasts differed in pan-cytokeratin expression from native trachea and did not show any improvement of differentiation. Immunohistochemical staining of MUC5AC and claudin-1 proved seeded cells being respiratory epithelial cells. CONCLUSIONS: This study indicates that adding fibroblasts to fibrin gel positively influences the differentiation of respiratory epithelium.

Population pharmacokinetics and dose simulation of carvedilol in paediatric patients with congestive heart failure.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: * Applying in silico tools such as population pharmacokinetic analysis and simulation will help to find adequate dosing strategies and increase the probability of success for a randomized controlled trial. * Up to now, for carvedilol in paediatric patients with congestive heart failure (CHF) the dose has been linearly extrapolated from adults, but the results with this dosing strategy are ambiguous. * Further trials are necessary to establish carvedilol for paediatric patients with CHF. WHAT THIS STUDY ADDS: * Carvedilol pharmacokinetics in paediatric patients with CHF depends on the weight and age of the patient. * Therefore, the drug exposure differs substantially between patients of different ages receiving the same dose with respect to body weight. * Simulations revealed that an age-adjusted carvedilol dosing strategy with higher doses for younger patients with respect to body weight is preferable to a uniform one. AIMS: To investigate the ontogeny of carvedilol pharmacokinetics and to develop an age-appropriate carvedilol dosing strategy for paediatric patients. METHODS: Data were derived from a prospective, nonplacebo-controlled study of carvedilol for the treatment of paediatric patients with congestive heart failure and analysed using a nonlinear mixed-effects modelling approach (NONMEM, Version V 1.1). The population pharmacokinetic model was further utilized for simulations of different carvedilol dosing strategies. RESULTS: Four hundred and eighty carvedilol plasma concentrations of 41 patients (0.1-19.3 years; median 3.5) were included in the analysis. A two-compartment model with first-order absorption and absorption lag served as structural model. Weight and age were the most important covariates for carvedilol pharmacokinetics. The weight-adjusted clearance was highest for the younger patients with 2.7 l h(-1) kg(-1) for a 1-year-old patient compared with 0.7 l h(-1) kg(-1) for a 19.3-year-old patient. Dose simulations revealed that the area under the plasma concentration-time curve (AUC) as a measure of drug exposure increased with age despite constant doses with respect to body weight. For infants (28 days to 23 months), children (2-11 years) and adolescents (12-15 years) daily doses of 3, 2 and 1 mg kg(-1), administered in two or three discrete doses, were necessary to reach an exposure comparable to adults receiving 0.7 mg kg(-1) day(-1). CONCLUSION: The ontogeny of carvedilol pharmacokinetics in paediatric patients depends on age and weight. Dose simulations revealed that younger patients have to be treated with higher doses with respect to body weight to reach the same exposure as adults.

[Drug interactions of tacrolimus]. / Arzneimittelinteraktionen von Tacrolimus.

Allogeneic hematopoetic stem cell transplantations can be complicated by a graft-versus-host disease (GvHD), i.e., immunocompetent cells from the transplanted bone marrow act against solid organs of the recipient. A GvHD is treated with immunosuppressants. Consequently, further drugs are required, for example in order to prevent infections and result in in polymedication of those patients with a risk of drug interactions. In this case report, drug interactions between tacrolimus and concomitant therapy in a stem-cell-transplanted patient are discussed.

N-Terminal pro-brain natriuretic peptide: normal ranges in the pediatric population including method comparison and interlaboratory variability.

The aim of the present study was the investigation of N-terminal pro-brain natriuretic peptide (NT-proBNP) in the pediatric population. This is essential for adequate monitoring and classification of pediatric patients with heart disease, but no consistent data are available yet. In addition, the comparability of two commercially available NT-proBNP assays and the inter-laboratory variability for the most suitable one were assessed. For this purpose, 408 subjects (1-29 years) were included. NT-proBNP was determined with a non-competitive electrochemiluminescent immunoassay (Roche NT-proBNP; n = 402) and a competitive enzyme-immunoassay (Biomedica NT-proBNP; n = 402). Inter-laboratory variability was evaluated for the Roche assay by stepwise inclusion of four and 11 centers throughout Germany, respectively. Roche NT-proBNP ranged from 5.0 to 391.5 ng/L, with higher values for younger children. The 97.5th (75th) percentile curve ranged from 319.9 ng/L (231.2 ng/L, 1-3 years) to 114.9 ng/L (53.3 ng/L, 18 years). In contrast, Biomedica NT-proBNP ranged from 253.7 to 7602.8 ng/L, with no significant age dependency. The mean difference between the assays was 1649.7 ng/L (95% confidence interval 1546.3-1753.1 ng/L). Inter-laboratory variability ranged from 6.5% to 3.8%, covering a range from 51.3 to 6618.1 ng/L. The assay seems to influence the interpretation of resulting NT-proBNP values and therefore has to be chosen carefully. For the monitoring and classification of pediatric patients with congenital heart disease, age-based NT-proBNP values should be used.

HPLC quantification of metoprolol with solid-phase extraction for the drug monitoring of pediatric patients.

Although the analytical literature seems abundant for the determination of metoprolol in human plasma, a method using standard equipment providing a sensitive and simple high-performance liquid chromatographic (HPLC) method for limited blood volume, e.g. where 1 mL of blood in a 1 kg infant equals 70 mL of adult blood volume, has rarely been addressed. Therefore, in 500 microL of plasma, metoprolol was extracted using an internal standard and solid-phase extraction columns. Chromatographic analysis was performed on a Spherisorb C(6) column (5 microm particle size) at ambient temperature and fluorimetric detection with an excitation wavelength of 225 nm, and emission wavelength of 310 nm. The mobile phase [30% acetonitrile and 70% 0.25 m potassium acetate buffer (pH 4)] was pumped with 1 mL/min. Metoprolol recovery was determined at 73.0 +/- 20.5%, and the limit of quantitation was 2.4 ng/mL. Precision values of intra- and inter-assay were below 15.5% and those for accuracy were between 90 and 110%. This method was developed for monitoring and determination of pharmacokinetic parameters of metoprolol in pediatric patients and therefore metoprolol plasma concentrations in a 2-year-old child with ventricular tachycardia are reported. .