253 research outputs found

    Development of quantitative metabolomics for Pichia pastoris

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    Accurate, reliable and reproducible measurement of intracellular metabolite levels has become important for metabolic studies of microbial cell factories. A first critical step for metabolomic studies is the establishment of an adequate quenching and washing protocol, which ensures effective arrest of all metabolic activity and removal of extracellular metabolites, without causing leakage of metabolites from the cells. Five different procedures based on cold methanol quenching and cell separation by filtration were tested for metabolomics of Pichia pastoris regarding methanol content and temperature of the quenching solution as key parameters. Quantitative evaluation of these protocols was carried out through mass balance analysis, based on metabolite measurements in all sample fractions, those are whole broth, quenched and washed cells, culture filtrate and quenching and washing solution. Finally, the optimal method was used to study the time profiles of free amino acid and central carbon metabolism intermediates in glucose-limited chemostat cultures. Acceptable recoveries (>90%) were obtained for all quenching procedures tested. However, quenching at −27°C in 60% v/v methanol performed slightly better in terms of leakage minimization. We could demonstrate that five residence times under glucose limitation are enough to reach stable intracellular metabolite pools. Moreover, when comparing P. pastoris and S. cerevisiae metabolomes, under the same cultivation conditions, similar metabolite fingerprints were found in both yeasts, except for the lower glycolysis, where the levels of these metabolites in P. pastoris suggested an enzymatic capacity limitation in that part of the metabolism

    Impact of immunosuppressive treatment and type of SARS-CoV-2 vaccine on antibody levels after three vaccinations in patients with chronic kidney disease or kidney replacement therapy

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    Background. Patients with chronic kidney disease (CKD) or kidney replacement therapy demonstrate lower antibody levels after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination compared with healthy controls. In a prospective cohort, we analysed the impact of immunosuppressive treatment and type of vaccine on antibody levels after three SARS-CoV-2 vaccinations. Methods. Control subjects (n = 186), patients with CKD G4/5 (n = 400), dialysis patients (n = 480) and kidney transplant recipients (KTR) (n = 2468) were vaccinated with either mRNA-1273 (Moderna), BNT162b2 (Pfizer-BioNTech) or AZD1222 (Oxford/AstraZeneca) in the Dutch SARS-CoV-2 vaccination programme. Third vaccination data were available in a subgroup of patients (n = 1829). Blood samples and questionnaires were obtained 1 month after the second and third vaccination. Primary endpoint was the antibody level in relation to immunosuppressive treatment and type of vaccine. Secondary endpoint was occurrence of adverse events after vaccination. Results. Antibody levels after two and three vaccinations were lower in patients with CKD G4/5 and dialysis patients with immunosuppressive treatment compared with patients without immunosuppressive treatment. After two vaccinations, we observed lower antibody levels in KTR using mycophenolate mofetil (MMF) compared with KTR not using MMF [20 binding antibody unit (BAU)/mL (3-113) vs 340 BAU/mL (50-1492), P &lt; .001]. Seroconversion was observed in 35% of KTR using MMF, compared with 75% of KTR not using MMF. Of the KTR who used MMF and did not seroconvert, eventually 46% seroconverted after a third vaccination. mRNA-1273 induces higher antibody levels as well as a higher frequency of adverse events compared with BNT162b2 in all patient groups. Conclusions. Immunosuppressive treatment adversely affects the antibody levels after SARS-CoV-2 vaccination in patients with CKD G4/5, dialysis patients and KTR. mRNA-1273 vaccine induces a higher antibody level and higher frequency of adverse events.</p

    Post COVID-19 condition imposes significant burden in patients with advanced chronic kidney disease:A nested case-control study

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    Background: The burden of post COVID-19 condition (PCC) is not well studied in patients with advanced kidney disease. Methods: A large prospective cohort of SARS-CoV-2 vaccinated patients with chronic kidney disease stages G4–G5 (CKD G4/5), on dialysis, and kidney transplant recipients (KTR) were included. Antibody levels were determined after vaccination. Presence of long-lasting symptoms was assessed in patients with and without prior COVID-19 and compared using logistic regression. In patients with prior COVID-19, PCC was defined according to the WHO definition. Results: Two hundred sixteen CKD G4/5 patients, 375 dialysis patients, and 2005 KTR were included. Long-lasting symptoms were reported in 204/853 (24%) patients with prior COVID-19 and in 297/1743 (17%) patients without prior COVID-19 (aOR: 1.45 (1.17–1.78)], P &lt; 0.001). PCC was prevalent in 29% of CKD G4/5 patients, 21% of dialysis patients, and 24% of KTR. In addition, 69% of patients with PCC reported (very) high symptom burden. Odds of PCC was lower per 10-fold increase in antibody level after vaccination (aOR 0.82 [0.70–0.96], P = 0.01) and higher in case of COVID-19 related hospital admission (aOR 4.64 [2.61–8.25], P = 0.003). Conclusions: CKD G4/5 patients, dialysis patients, and KTR are at risk for PCC with high symptom burden after SARS-CoV-2 vaccination, especially if antibody levels are low and in case of hospitalization due to COVID-19.</p

    Construction and psychometric testing of the EMPATHIC questionnaire measuring parent satisfaction in the pediatric intensive care unit

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    General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract Purpose: To construct and test the reliability and validity of the EMpowerment of PArents in THe Intensive Care (EMPATHIC) questionnaire measuring parent satisfaction in the pediatric intensive care unit (PICU). Methods: Structured development and psychometric testing of a parent satisfaction-withcare instrument with the results of two cohorts of parents (n = 2,046) from eight PICUs in the Netherlands. Results: In the first cohort, 667/ 1,055 (63%) parents participated followed by 551/991 (56%) parents in the second cohort. The empirical structure of the instrument was established by confirmatory factor analysis with the first sample of parents confirming 65 statements within five theoretically conceptualized domains: information, care and cure, organization, parental participation, and professional attitude. The standardized factor loadings were greater than 0.40 in 63 statements. Cronbach&apos;s a, a measure of reliability, per domain ranged from 0.73 to 0.93 in both cohorts with no significant difference documenting the reliability over time. Beside rigorous content and face validity, the congruent validity of the instrument showed adequate correlation with four gold standard questions measuring overall satisfaction. The nondifferential validity was confirmed with no significant differences between the population characteristics and the domains, except that parents with a child for a surgical admission were more satisfied on information issues. Intensive Care Med (2011) 37:310-318 DOI 10.1007/s00134-010-2042 PEDIATRIC ORIGINAL Conclusions: The final EMPATHIC questionnaire incorporates 65 statements. The empirical structure of the satisfaction statements and domains was satisfactory. The reliability and validity proved to be adequate. The EMPATHIC questionnaire is a valid quality performance indicator to measure quality of care as perceived by parents

    Combination antiretroviral therapy and the risk of myocardial infarction

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    Predicting overall survival and resection in patients with locally advanced pancreatic cancer treated with FOLFIRINOX:Development and internal validation of two nomograms

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    Background and Objectives Patients with locally advanced pancreatic cancer (LAPC) are increasingly treated with FOLFIRINOX, resulting in improved survival and resection of tumors that were initially unresectable. It remains unclear, however, which specific patients benefit from FOLFIRINOX. Two nomograms were developed predicting overall survival (OS) and resection at the start of FOLFIRINOX for LAPC. Methods From our multicenter, prospective LAPC registry in 14 Dutch hospitals, LAPC patients starting first-line FOLFIRINOX (April 2015-December 2017) were included. Stepwise backward selection according to the Akaike Information Criterion was used to identify independent baseline predictors for OS and resection. Two prognostic nomograms were generated. Results A total of 252 patients were included, with a median OS of 14 months. Thirty-two patients (13%) underwent resection, with a median OS of 23 months. Older age, female sex, Charlson Comorbidity Index 1, involvement of the superior mesenteric artery, celiac trunk, and superior mesenteric vein >= 270 degrees were independent factors decreasing the probability of resection (c-index: 0.79). Conclusions Two nomograms were developed to predict OS and resection in patients with LAPC before starting treatment with FOLFIRINOX. These nomograms could be beneficial in the shared decision-making process and counseling of these patients

    Construction and psychometric testing of the EMPATHIC questionnaire measuring parent satisfaction in the pediatric intensive care unit

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    Abstract PURPOSE: To construct and test the reliability and validity of the EMpowerment of PArents in THe Intensive Care (EMPATHIC) questionnaire measuring parent satisfaction in the pediatric intensive care unit (PICU). METHODS: Structured development and psychometric testing of a parent satisfaction-with-care instrument with the results of two cohorts of parents (n = 2,046) from eight PICUs in the Netherlands. RESULTS: In the first cohort, 667/1,055 (63%) parents participated followed by 551/991 (56%) parents in the second cohort. The empirical structure of the instrument was established by confirmatory factor analysis with the first sample of parents confirming 65 statements within five theoretically conceptualized domains: information, care and cure, organization, parental participation, and professional attitude. The standardized factor loadings were greater than 0.40 in 63 statements. Cronbach's α, a measure of reliability, per domain ranged from 0.73 to 0.93 in both cohorts with no significant difference documenting the reliability over time. Beside rigorous content and face validity, the congruent validity of the instrument showed adequate correlation with four gold standard questions measuring overall satisfaction. The non-differential validity was confirmed with no significant differences between the population characteristics and the domains, except that parents with a child for a surgical admission were more satisfied on information issues. CONCLUSIONS: The final EMPATHIC questionnaire incorporates 65 statements. The empirical structure of the satisfaction statements and domains was satisfactory. The reliability and validity proved to be adequate. The EMPATHIC questionnaire is a valid quality performance indicator to measure quality of care as perceived by parents

    Textbook Outcome Nationwide Analysis of a Novel Quality Measure in Pancreatic Surgery:Nationwide Analysis of a Novel Quality Measure in Pancreatic Surgery

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    Background: Textbook outcome (TO) is a multidimensional measure for quality assurance, reflecting the ‘‘ideal’’ surgical outcome. Methods: Post-hoc analysis of patients who underwent pancreatoduodenectomy (PD) or distal pancreatectomy (DP) for all indications between 2014 and 2017, queried from the nationwide prospective Dutch Pancreatic Cancer Audit. An international survey was conducted among 24 experts from 10 countries to reach consensus on the requirements for TO in pancreatic surgery. Univariable and multivariable logistic regression was performed to identify TO predictors. Between-hospital variation in TO rates was compared using observed-versus-expected rates. Results: Based on the survey (92% response rate), TO was defined by the absence of postoperative pancreatic fistula, bile leak, postpancreatectomy hemorrhage (all ISGPS grade B/C), severe complications (Clavien–Dindo III), readmission, and in-hospital mortality. Overall, 3341 patients were included (2633 (79%) PD and 708 (21%) DP) of whom 60.3% achieved TO; 58.3% for PD and 67.4% for DP. On multivariable analysis, ASA class 3 predicted a worse TO rate after PD (ASA 3 OR 0.59 [0.44–0.80]), whereas a dilated pancreatic duct (>3 mm) and pancreatic ductal ade

    Detection, Treatment, and Survival of Pancreatic Cancer Recurrence in the Netherlands A Nationwide Analysis

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    OBJECTIVE: To evaluate whether detection of recurrent pancreatic ductal adenocarcinoma (PDAC) in an early, asymptomatic stage increases the number of patients receiving additional treatment, subsequently improving survival. SUMMARY OF BACKGROUND DATA: International guidelines disagree on the value of standardized postoperative surveillance for early detection and treatment of PDAC recurrence. METHODS: A nationwide, observational cohort study was performed including all patients who underwent PDAC resection (2014-2016). Prospective baseline and perioperative data were retrieved from the Dutch Pancreatic Cancer Audit. Data on follow-up, treatment, and survival were collected retrospectively. Overall survival (OS) was evaluated using multivariable Cox regression analysis, before and after propensity-score matching, stratified for patients with symptomatic and asymptomatic recurrence. RESULTS: Eight hundred thirty-six patients with a median follow-up of 37 months (interquartile range 30-48) were analyzed. Of those, 670 patients (80%) developed PDAC recurrence after a median follow-up of 10 months (interquartile range 5-17). Additional treatment was performed in 159/511 patients (31%) with symptomatic recurrence versus 77/159 (48%) asymptomatic patients (P < 0.001). After propensity-score matching on lymph node ratio, adjuvant therapy, disease-free survival, and recurrence site, additional treatment was independently associated with improved OS for both symptomatic patients [hazard ratio 0.53 (95% confidence interval 0.42-0.67); P < 0.001] and asymptomatic patients [hazard ratio 0.45 (95% confidence interval 0.29-0.70); P < 0.001]. CONCLUSIONS: Additional treatment of PDAC recurrence was independently associated with improved OS, with asymptomatic patients having a higher probability to receive recurrence treatment. Therefore, standardized postoperative surveillance aiming to detect PDAC recurrence before the onset of symptoms has the potential to improve survival. This provides a rationale for prospective studies on standardized surveillance after PDAC resection
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