@article{ForchertPotapovaPanettaetal.2022, author = {Forchert, Leandra and Potapova, Ekaterina and Panetta, Valentina and Dramburg, Stephanie and Perna, Serena and Posa, Daniela and Resch-Marat, Yvonne and Lupinek, Christian and Rohrbach, Alexander and Grabenhenrich, Linus and Icke, Katja and Bauer, Carl-Peter and Hoffman, Ute and Forster, Johannes and Zepp, Fred and Schuster, Antje and Wahn, Ulrich and Keil, Thomas and Lau, Susanne and Vrtala, Susanne and Valenta, Rudolf and Matricardi, Paolo Maria}, title = {Der p 23-specific IgE response throughout childhood and its association with allergic disease: A birth cohort study}, series = {Pediatric Allergy and Immunology}, volume = {33}, journal = {Pediatric Allergy and Immunology}, number = {7}, doi = {10.1111/pai.13829}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287181}, year = {2022}, abstract = {Background The Dermatophagoides pteronyssinus molecule Der p 23 is a major allergen whose clinical relevance has been shown in cross-sectional studies. We longitudinally analysed the trajectory of Der p 23-specific IgE antibody (sIgE) levels throughout childhood and youth, their early-life determinants and their clinical relevance for allergic rhinitis and asthma. Methods We obtained sera and clinical data of 191 participants of the German Multicentre Allergy Study, a prospective birth cohort. Serum samples from birth to 20 years of age with sIgE reactivity to Der p 23 in a customised semiquantitative microarray were newly analysed with a singleplex quantitative assay. Early mite exposure was assessed by measuring the average content of Der p 1 in house dust at 6 and 18 months. Results Der p 23-sIgE levels were detected at least once in 97/191 participants (51\%). Prevalence of Der p 23 sensitisation and mean sIgE levels increased until age 10 years, plateaued until age 13 years and were lowest at age 20 years. Asthma, allergic rhinitis (AR) and atopic dermatitis (AD) were more prevalent in Der p 23-sensitised children, including those with monomolecular but persistent sensitisation (11/97, 11\%). A higher exposure to mites in infancy and occurrence of AD before 5 years of age preceded the onset of Der p 23 sensitisation, which in turn preceded a higher incidence of asthma. Conclusions Der p 23 sensitisation peaks in late childhood and then decreases. It is preceded by early mite exposure and AD. Asthma and AR can occur in patients persistently sensitised to Der p 23 as the only mite allergen, suggesting the inclusion of molecular testing of Der p 23-sIgE for subjects with clinical suspicion of HDM allergy but without sIgE to other major D.pt. allergens.}, language = {en} } @article{ForsterKohlmorgenHaasetal.2022, author = {Forster, Johannes and Kohlmorgen, Britta and Haas, Julian and Weis, Philipp and Breunig, Lukas and Turnwald, Doris and Mizaikoff, Boris and Schoen, Christoph}, title = {A streamlined method for the fast and cost-effective detection of bacterial pathogens from positive blood cultures for the BacT/ALERT blood culture system using the Vitek MS mass spectrometer}, series = {PLoS ONE}, volume = {17}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0267669}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300213}, year = {2022}, abstract = {Background and objective Prompt pathogen identification of blood stream infections is essential to provide appropriate antibiotic treatment. Therefore, the objective of this prospective single centre study was to establish an inexpensive, fast and accurate protocol for bacterial species identification with SDS protein-extraction directly from BacT/Alert® blood culture (BC) bottles by VitekMS®. Results Correct species identification was obtained for 198/266 (74.4\%, 95\%-CI = [68.8\%, 79.6\%]) of pathogens. The protocol was more successful in identifying 87/96 (91.4\%, 95\%-CI = [83.8\%, 93.2\%]) gram-negative bacteria than 110/167 (65.9\%, 95\%-CI = [58.1\%, 73.0\%]) gram-positive bacteria. The hands-on time for sample preparation and measurement was about 15 min for up to five samples. This is shorter than for most other protocols using a similar lysis-centrifugation approach for the combination of BacT/Alert® BC bottles and the Vitek® MS mass spectrometer. The estimated costs per sample were approx. 1.80€ which is much cheaper than for commercial kits. Conclusion This optimized protocol allows for accurate identification of bacteria directly from blood culture bottles for laboratories equipped with BacT/Alert® blood culture bottles and VitekMS® mass spectrometer.}, language = {en} } @article{ForsterDichtlWagener2022, author = {Forster, Johannes and Dichtl, Karl and Wagener, Johannes}, title = {Lower beta-1,3-D-glucan testing cut-offs increase sensitivity for non-albicans Candida species bloodstream infections}, series = {Mycoses}, volume = {65}, journal = {Mycoses}, number = {5}, doi = {10.1111/myc.13421}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276515}, pages = {500 -- 507}, year = {2022}, abstract = {Purpose Fungal biomarkers support early diagnosis of invasive fungal infections. In this study, we evaluated the impact of a recent update to the manufacturer-recommended cut-off for beta-1,3-D-glucan (BDG) testing (Fujifilm Wako BDG assay) on sensitivity and specificity for the detection of candidemia. Additionally, we compared the performance with tests for Candida antigen (Ag by Serion ELISA antigen Candida, Virion\Serion) and anti-mannan antibodies (Ab by Hemkit Candida IHA, Ravo Diagnostika). Methods Sera of 82 patients with candidemia, which were sampled with a maximum distance of ±14 days from the date of sampling of the corresponding positive blood cultures, were retrospectively analysed for BDG, Ag and Ab. Results of BDG testing were compared with results from sera of 129 patients with candidemia from a different hospital. Results Sensitivity of BDG testing (47\%) was higher than for Ag (17\%) or Ab (20\%). By combining Ag and Ab testing, sensitivity was raised to 32\%. Lowering the cut-off of BDG from 11 pg/ml to the newly recommended cut-off of 7 pg/ml resulted in a significant increase in sensitivity (47\% vs 58\%, p = .01 and 63\% vs 71\% p < .01). At both centres, the increase was significant in NAC but not in C. albicans candidemia. No significant effects on specificity were observed. Conclusion BDG testing outperformed Ag and Ab testing and its combination. Lowering the BDG cut-off had no significant impact on specificity. The increase in sensitivity can be mainly attributed to a gain in sensitivity for non-albicans Candida species bloodstream infections.}, language = {en} } @article{StreckForstervonHertzbergBoelchetal.2022, author = {Streck, Laura Elisa and Forster, Johannes and von Hertzberg-Boelch, Sebastian Philipp and Reichel, Thomas and Rudert, Maximilian and Rueckl, Kilian}, title = {The role of synovial fluid aspiration in shoulder joint infections}, series = {BMC Musculoskeletal Disorders}, volume = {23}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-022-05285-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300795}, year = {2022}, abstract = {Background Joint aspiration with analysis of synovial fluid white blood cell count (WBC) and microbiological culture is a widely established aspect in the diagnosis of shoulder joint infections (SJI). In case of a two stage revision for SJI, joint aspiration before re-/implantation of a total shoulder arthroplasty (TSA) was used to rule out persistent infection for years but its value is under debate. Shoulder specific data on all aspects is rare. The current study aims to answer the following research questions: Does joint aspiration have an insufficient predictive value in the diagnosis of SJI in (1) initial workup and (2) before definite arthroplasty with polymethylmethacrylate (PMMA)-Spacer in place? Methods This retrospective evaluation investigates 35 patients that were treated for SJI with a two staged implantation of a TSA after debridement and implantation of an PMMA-Spacer. Joint aspirations were performed preoperatively (PA) and before re-/implantation of the prosthesis while spacer was in place (interstage aspiration, IA). Samples were taken for microbiological culture and analysis of WBC. Sensitivity and specificity were calculated with reference to intraoperative microbiological samples. Receiver Operating Characteristic (ROC), Area-Under-Curve analysis (AUC) and calculation of the Youden index were performed to find optimum cut-off for WBC. Results The sensitivity of microbiological cultures from PA was 58.3\% and the specificity was 88.9\%. The mean WBC was 27,800 leucocytes/mm3 (range 400-96,300). The maximum Youden index (0.857) was a cut-off of 2600 leucocytes/mm3 with a sensitivity of 85.7\% and a specificity of 100.0\%. The sensitivity and specificity of IA were 0.0\% and 88.5\%, respectively. Conclusions Preoperative aspiration is likely to miss Cutibacteria spp. and CoNS and cannot rule out infection for sure. However, we recommend it for its advantages of targeted antibiotic therapy in case of germ identification. Empiric antibiotic therapy should cover Cutibacteria and CoNS even if aspiration showed negative microbiological cultures. In contrast, the diagnostic value of interstage aspiration does not qualify for its routine use.}, language = {en} } @article{KurotschkaTiedemannWolfetal.2021, author = {Kurotschka, Peter Konstantin and Tiedemann, Elena and Wolf, Dominik and Thier, Nicola and Forster, Johannes and Liese, Johannes G. and Gagyor, Ildiko}, title = {Management of common infections in German primary care: a cross-sectional survey of knowledge and confidence among General Practitioners and outpatient pediatricians}, series = {Antibiotics}, volume = {10}, journal = {Antibiotics}, number = {9}, issn = {2079-6382}, doi = {10.3390/antibiotics10091131}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246272}, year = {2021}, abstract = {Outpatient antibiotic use is closely related to antimicrobial resistance and in Germany, almost 70\% of antibiotic prescriptions in human health are issued by primary care physicians (PCPs). The aim of this study was to explore PCPs, namely General Practitioners' (GPs) and outpatient pediatricians' (PDs) knowledge of guideline recommendations on rational antimicrobial treatment, the determinants of confidence in treatment decisions and the perceived need for training in this topic in a large sample of PCPs from southern Germany. Out of 3753 reachable PCPs, 1311 completed the survey (overall response rate = 34.9\%). Knowledge of guideline recommendations and perceived confidence in making treatment decisions were high in both GPs and PDs. The two highest rated influencing factors on prescribing decisions were reported to be guideline recommendations and own clinical experiences, hence patients' demands and expectations were judged as not influencing treatment decisions. The majority of physicians declared to have attended at least one specific training course on antibiotic use, yet almost all the participating PCPs declared to need more training on this topic. More studies are needed to explore how consultation-related and context-specific factors could influence antibiotic prescriptions in general and pediatric primary care in Germany beyond knowledge. Moreover, efforts should be undertaken to explore the training needs of PCPs in Germany, as this would serve the development of evidence-based educational interventions targeted to the improvement of antibiotic prescribing decisions rather than being focused solely on knowledge of guidelines.}, language = {en} } @article{StreckGaalForsteretal.2021, author = {Streck, Laura Elisa and Gaal, Chiara and Forster, Johannes and Konrads, Christian and Hertzberg-Boelch, Sebastian Philipp von and Rueckl, Kilian}, title = {Defining a synovial fluid white blood cell count threshold to predict periprosthetic infection after shoulder arthroplasty}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {1}, issn = {2077-0383}, doi = {10.3390/jcm11010050}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252275}, year = {2021}, abstract = {Background: The diagnosis of periprosthetic shoulder infection (PSI) requires a thorough diagnostic workup. Synovial fluid aspiration has been proven to be a reliable tool in the diagnosis of joint infections of the lower extremity, but shoulder specific data is limited. This study defines a threshold for synovial fluid white blood cell count (WBC) and assesses the reliability of microbiological cultures. Methods: Retrospective study of preoperative and intraoperative fluid aspiration of 31 patients who underwent a revision of a shoulder arthroplasty (15 with PSI defined by IDSA criteria, 16 without infection). The threshold for WBC was calculated by ROC/AUC analysis. Results: WBC was significantly higher in patients with PSI than in other patients. A threshold of 2800 leucocytes/mm\(^3\) showed a sensitivity of 87\% and a specificity of 88\% (AUROC 0.92). Microbiological cultures showed a sensitivity of 76\% and a specificity of 100\%. Conclusions: A threshold of 2800 leucocytes/mm\(^3\) in synovial fluid can be recommended to predict PSI. Microbiological culture has an excellent specificity and allows for targeted antibiotic therapy. Joint aspiration presents an important pillar to diagnose PSI.}, language = {en} } @article{DichtlForsterOrmannsetal.2020, author = {Dichtl, Karl and Forster, Johannes and Ormanns, Steffen and Horns, Heidi and Suerbaum, Sebastian and Seybold, Ulrich and Wagener, Johannes}, title = {Comparison of β-D-Glucan and galactomannan in serum for detection of invasive aspergillosis: retrospective analysis with focus on early diagnosis}, series = {Journal of Fungi}, volume = {6}, journal = {Journal of Fungi}, number = {4}, issn = {2309-608X}, doi = {10.3390/jof6040253}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216298}, year = {2020}, abstract = {The early diagnosis of invasive aspergillosis (IA) relies mainly on computed tomography imaging and testing for fungal biomarkers such as galactomannan (GM). We compared an established ELISA for the detection of GM with a turbidimetric assay for detection of the panfungal biomarker β-D-glucan (BDG) for early diagnosis of IA. A total of 226 serum specimens from 47 proven and seven probable IA cases were analysed. Sensitivity was calculated for samples obtained closest to the day of IA-diagnosis (d0). Additional analyses were performed by including samples obtained during the presumed course of disease. Most IA cases involved the respiratory system (63\%), and Aspergillus fumigatus was the most frequently isolated species (59\%). For proven cases, sensitivity of BDG/GM analysis was 57\%/40\%. Including all samples dating from -6 to +1 weeks from d0 increased sensitivities to 74\%/51\%. Sensitivity of BDG testing was as high as or higher than GM testing for all subgroups and time intervals analysed. BDG testing was less specific (90-93\%) than GM testing (99-100\%). Combining BDG and GM testing resulted in sensitivity/specificity of 70\%/91\%. Often, BDG testing was positive before GM testing. Our study backs the use of BDG for diagnosis of suspected IA. We suggest combining BDG and GM to improve the overall sensitivity.}, language = {en} } @phdthesis{Forster2016, author = {Forster, Johannes}, title = {Variational Approach to the Modeling and Analysis of Magnetoelastic Materials}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147226}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {This doctoral thesis is concerned with the mathematical modeling of magnetoelastic materials and the analysis of PDE systems describing these materials and obtained from a variational approach. The purpose is to capture the behavior of elastic particles that are not only magnetic but exhibit a magnetic domain structure which is well described by the micromagnetic energy and the Landau-Lifshitz-Gilbert equation of the magnetization. The equation of motion for the material's velocity is derived in a continuum mechanical setting from an energy ansatz. In the modeling process, the focus is on the interplay between Lagrangian and Eulerian coordinate systems to combine elasticity and magnetism in one model without the assumption of small deformations. The resulting general PDE system is simplified using special assumptions. Existence of weak solutions is proved for two variants of the PDE system, one including gradient flow dynamics on the magnetization, and the other featuring the Landau-Lifshitz-Gilbert equation. The proof is based on a Galerkin method and a fixed point argument. The analysis of the PDE system with the Landau-Lifshitz-Gilbert equation uses a more involved approach to obtain weak solutions based on G. Carbou and P. Fabrie 2001.}, subject = {Magnetoelastizit{\"a}t}, language = {en} } @article{GrabenhenrichReichFischeretal.2014, author = {Grabenhenrich, Linus B. and Reich, Andreas and Fischer, Felix and Zepp, Fred and Forster, Johannes and Schuster, Antje and Bauer, Carl-Peter and Bergmann, Renate L. and Bergmann, Karl E. and Wahn, Ulrich and Keil, Thomas and Lau, Susanne}, title = {The Novel 10-Item Asthma Prediction Tool: External Validation in the German MAS Birth Cohort}, series = {PLOS ONE}, volume = {9}, journal = {PLOS ONE}, number = {12}, issn = {1932-6203}, doi = {10.1371/journal.pone.0115852}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-114202}, pages = {e115852}, year = {2014}, abstract = {Background: A novel non-invasive asthma prediction tool from the Leicester Cohort, UK, forecasts asthma at age 8 years based on 10 predictors assessed in early childhood, including current respiratory symptoms, eczema, and parental history of asthma. Objective: We aimed to externally validate the proposed asthma prediction method in a German birth cohort. Methods: The MAS-90 study (Multicentre Allergy Study) recorded details on allergic diseases prospectively in about yearly follow-up assessments up to age 20 years in a cohort of 1,314 children born 1990. We replicated the scoring method from the Leicester cohort and assessed prediction, performance and discrimination. The primary outcome was defined as the combination of parent-reported wheeze and asthma drugs (both in last 12 months) at age 8. Sensitivity analyses assessed model performance for outcomes related to asthma up to age 20 years. Results: For 140 children parents reported current wheeze or cough at age 3 years. Score distribution and frequencies of later asthma resembled the Leicester cohort: 9\% vs. 16\% (MAS-90 vs. Leicester) of children at low risk at 3 years had asthma at 8 years, at medium risk 45\% vs. 48\%. Performance of the asthma prediction tool in the MAS-90 cohort was similar (Brier score 0.22 vs. 0.23) and discrimination slightly better than in the original cohort (area under the curve, AUC 0.83 vs. 0.78). Prediction and discrimination were robust against changes of inclusion criteria, scoring and outcome definitions. The secondary outcome 'physicians' diagnosed asthma at 20 years' showed the highest discrimination (AUC 0.89). Conclusion: The novel asthma prediction tool from the Leicester cohort, UK, performed well in another population, a German birth cohort, supporting its use and further development as a simple aid to predict asthma risk in clinical settings.}, language = {en} } @misc{Forster2013, type = {Master Thesis}, author = {Forster, Johannes}, title = {Mathematical Modeling of Complex Fluids}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83533}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {This thesis gives an overview over mathematical modeling of complex fluids with the discussion of underlying mechanical principles, the introduction of the energetic variational framework, and examples and applications. The purpose is to present a formal energetic variational treatment of energies corresponding to the models of physical phenomena and to derive PDEs for the complex fluid systems. The advantages of this approach over force-based modeling are, e.g., that for complex systems energy terms can be established in a relatively easy way, that force components within a system are not counted twice, and that this approach can naturally combine effects on different scales. We follow a lecture of Professor Dr. Chun Liu from Penn State University, USA, on complex fluids which he gave at the University of Wuerzburg during his Giovanni Prodi professorship in summer 2012. We elaborate on this lecture and consider also parts of his work and publications, and substantially extend the lecture by own calculations and arguments (for papers including an overview over the energetic variational treatment see [HKL10], [Liu11] and references therein).}, subject = {Variationsrechnung}, language = {en} }