TY  - JOUR
A1  - Reinecke, Robert
A1  - Trautmann, Tim
A1  - Wagener, Thorsten
A1  - Schüler, Katja
T1  - The critical need to foster computational reproducibility
JF  - Environmental research letters
KW  - reproducibility
KW  - models
KW  - software
KW  - Open Science
Y1  - 2022
U6  - https://doi.org/10.1088/1748-9326/ac5cf8
SN  - 1748-9326
VL  - 17
IS  - 4
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Deutschmann, Claudia
A1  - Roggenbuck, Dirk
A1  - Schierack, Peter
A1  - Rödiger, Stefan
T1  - Autoantibody testing by enzyme-linked immunosorbent assay-a case in which the solid phase decides on success and failure
JF  - Heliyon
N2  - Background: The enzyme-linked immunosorbent assay (ELISA) is an indispensable tool for clinical diagnostics to identify or differentiate diseases such as autoimmune illnesses, but also to monitor their progression or control the efficacy of drugs. One use case of ELISA is to differentiate between different states (e.g. healthy vs. diseased). Another goal is to quantitatively assess the biomarker in question, like autoantibodies. Thus, the ELISA technology is used for the discovery and verification of new autoantibodies, too. Of key interest, however, is the development of immunoassays for the sensitive and specific detection of such biomarkers at early disease stages. Therefore, users have to deal with many parameters, such as buffer systems or antigen-autoantibody interactions, to successfully establish an ELISA. Often, fine-tuning like testing of several blocking substances is performed to yield high signal-to-noise ratios. <br /> Methods: We developed an ELISA to detect IgA and IgG autoantibodies against chitinase-3-like protein 1 (CHI3L1), a newly identified autoantigen in inflammatory bowel disease (IBD), in the serum of control and disease groups (n = 23, respectively). Microwell plates with different surface modifications (PolySorp and MaxiSorp coating) were tested to detect reproducibility problems. <br /> Results: We found a significant impact of the surface properties of the microwell plates. IgA antibody reactivity was significantly lower, since it was in the range of background noise, when measured on MaxiSorp coated plates (p < 0.0001). The IgG antibody reactivity did not differ on the diverse plates, but the plate surface had a significant influence on the test result (p = 0.0005). <br /> Conclusion: With this report, we want to draw readers' attention to the properties of solid phases and their effects on the detection of autoantibodies by ELISA. We want to sensitize the reader to the fact that the choice of the wrong plate can lead to a false negative test result, which in turn has serious consequences for the discovery of autoantibodies.
KW  - biochemistry
KW  - coatings
KW  - surface chemistry
KW  - immunology
KW  - proteins
KW  - laboratory medicine
KW  - clinical research
KW  - enzyme-linked immunosorbent
KW  - assay
KW  - biomarker discovery
KW  - reproducibility
KW  - solid-phase
KW  - autoantibody
Y1  - 2020
U6  - https://doi.org/10.1016/j.heliyon.2020.e03270
SN  - 2405-8440
VL  - 6
IS  - 1
PB  - Elsevier
CY  - London [u.a.]
ER  - 
TY  - JOUR
A1  - Rector, Michael V.
A1  - Intziegianni, Konstantina
A1  - Müller, Steffen
A1  - Mayer, Frank
A1  - Cassel, Michael
T1  - Reproducibility of an ankle joint rotation correction method for assessment of Achilles tendon elongation
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - BACKGROUND: The Achilles tendon (AT) requires optimal material and mechanical properties to function properly. Calculation of these properties depends on accurate measurement of input parameters (i.e. tendon elongation). However, the measurement of AT elongation with ultrasound during maximum voluntary isometric contraction (MVIC) is overestimated by ankle joint rotation (AJR). Methods to correct the influence of this rotation on AT elongation exist, yet their reproducibility in clinical settings is unknown. OBJECTIVE: To evaluate the test-retest reproducibility of AT elongation during MVIC after AJR correction. METHODS: Ten participants attended test and retest measurements where they performed plantar-flexion MVIC on a dynamometer. Simultaneously, ultrasound recorded AT elongation as the displacement of the medial gastrocnemius-myotendinous junction, while an electrogoniometer measured AJR. The ankle was then passively rotated to the AJR achieved during MVIC and AT elongation again determined. Elongation was corrected by subtracting this passive AT elongation from the total AT elongation during MVIC. Reproducibility was evaluated using ICC (2.1), test-retest variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]) and standard error of the measurement (SEM). RESULTS: Corrected AT elongation reproducibility exhibited an ICC = 0.79, SEM = 0.2 cm and TRV = 20 +/- 19%. Bias +/- LoA were determined to be 0.0 +/- 0.8 cm. CONCLUSIONS: Using this ultrasound and electrogoniometer-based method, corrected AT elongation can be assessed reproducibly.
KW  - Ultrasonography
KW  - Achilles tendon
KW  - reproducibility
KW  - isokinetic
KW  - ankle joint rotation
Y1  - 2017
U6  - https://doi.org/10.3233/IES-160644
SN  - 0959-3020
SN  - 1878-5913
VL  - 25
IS  - 1
SP  - 47
EP  - 52
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schenk, Matthew
A1  - Eichelmann, Fabian
A1  - Schulze, Matthias Bernd
A1  - Rudovich, Natalia
A1  - Pfeiffer, Andreas F. H.
A1  - di Giuseppe, Romina
A1  - Böing, Heiner
A1  - Aleksandrova, Krasimira
T1  - Reproducibility of novel immune-inflammatory biomarkers over 4 months
BT  - an analysis with repeated measures design
JF  - Biomarkers in medicine
N2  - Aim: Assessment of the feasibility and reliability of immune-inflammatory biomarker measurements. Methods: The following biomarkers were assessed in 207 predominantly healthy participants at baseline and after 4 months: MMF, TGF-beta, suPAR and clusterin. Results: Intraclass correlation coefficients (95% CIs) ranged from good for TGF-beta (0.75 [95% CI: 0.33-0.90]) to excellent for MMF (0.81 [95% CI: 0.64-0.90]), clusterin (0.83 [95% CI: 0.78-0.87]) and suPAR (0.91 [95% CI: 0.88-0.93]). Measurement of TGF-beta was challenged by the large number of values below the detection limit. Conclusion: Single measurements of suPAR, clusterin and MMF could serve as feasible and reliable biomarkers of immune-inflammatory pathways in biomedical research.
KW  - clusterin
KW  - immune-inflammatory biomarkers
KW  - MMF
KW  - repeated measures design
KW  - reproducibility
KW  - suPAR
KW  - TGF-beta
Y1  - 2019
U6  - https://doi.org/10.2217/bmm-2018-0351
SN  - 1752-0363
SN  - 1752-0371
VL  - 13
IS  - 8
SP  - 639
EP  - 648
PB  - Future Medicine
CY  - London
ER  - 
TY  - GEN
A1  - Bittmann, Frank
A1  - Dech, Silas
A1  - Aehle, Markus
A1  - Schaefer, Laura
T1  - Manual Muscle Testing—Force Profiles and Their Reproducibility
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - The manual muscle test (MMT) is a flexible diagnostic tool, which is used in many disciplines, applied in several ways. The main problem is the subjectivity of the test. The MMT in the version of a “break test” depends on the tester’s force rise and the patient’s ability to resist the applied force. As a first step, the investigation of the reproducibility of the testers’ force profile is required for valid application. The study examined the force profiles of n = 29 testers (n = 9 experiences (Exp), n = 8 little experienced (LitExp), n = 12 beginners (Beg)). The testers performed 10 MMTs according to the test of hip flexors, but against a fixed leg to exclude the patient’s reaction. A handheld device recorded the temporal course of the applied force. The results show significant differences between Exp and Beg concerning the starting force (padj = 0.029), the ratio of starting to maximum force (padj = 0.005) and the normalized mean Euclidean distances between the 10 trials (padj = 0.015). The slope is significantly higher in Exp vs. LitExp (p = 0.006) and Beg (p = 0.005). The results also indicate that experienced testers show inter-tester differences and partly even a low intra-tester reproducibility. This highlights the necessity of an objective MMT-assessment. Furthermore, an agreement on a standardized force profile is required. A suggestion for this is given.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 671 
KW  - manual muscle testing
KW  - neuromuscular diagnostics
KW  - force profiles
KW  - reproducibility
KW  - adaptive force
KW  - handheld device
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-485612
SN  - 1866-8364
IS  - 671
ER  - 
TY  - JOUR
A1  - Bittmann, Frank
A1  - Dech, Silas
A1  - Aehle, Markus
A1  - Schaefer, Laura
T1  - Manual Muscle Testing—Force Profiles and Their Reproducibility
JF  - Diagnostics
N2  - The manual muscle test (MMT) is a flexible diagnostic tool, which is used in many disciplines, applied in several ways. The main problem is the subjectivity of the test. The MMT in the version of a “break test” depends on the tester’s force rise and the patient’s ability to resist the applied force. As a first step, the investigation of the reproducibility of the testers’ force profile is required for valid application. The study examined the force profiles of n = 29 testers (n = 9 experiences (Exp), n = 8 little experienced (LitExp), n = 12 beginners (Beg)). The testers performed 10 MMTs according to the test of hip flexors, but against a fixed leg to exclude the patient’s reaction. A handheld device recorded the temporal course of the applied force. The results show significant differences between Exp and Beg concerning the starting force (padj = 0.029), the ratio of starting to maximum force (padj = 0.005) and the normalized mean Euclidean distances between the 10 trials (padj = 0.015). The slope is significantly higher in Exp vs. LitExp (p = 0.006) and Beg (p = 0.005). The results also indicate that experienced testers show inter-tester differences and partly even a low intra-tester reproducibility. This highlights the necessity of an objective MMT-assessment. Furthermore, an agreement on a standardized force profile is required. A suggestion for this is given.
KW  - manual muscle testing
KW  - neuromuscular diagnostics
KW  - force profiles
KW  - reproducibility
KW  - adaptive force
KW  - handheld device
Y1  - 2020
U6  - https://doi.org/10.3390/diagnostics10120996
SN  - 2075-4418
VL  - 10
IS  - 12
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - König, Niklas
A1  - Müller, Steffen
A1  - Fröhlich, Katja
A1  - Mayer, Frank
T1  - Ultrasonography for the assessment of the structural properties of the Achilles tendon in asymptomatic individuals: An intra-rater reproducibility study
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - BACKGROUND: Reproducible measurements of tendon structural properties are a prerequisite for accurate diagnosis of tendon disorders and for determination of their mechanical properties. Despite the widely used application of Ultrasonography (US) in musculoskeletal assessment, its operator dependency and lack of standardization influences the consistency of the measurement.
 OBJECTIVE: To evaluate the intra-rater reproducibility of a standardized US method assessing the structural properties of the Achilles tendon (AT).
 METHODS: Sixteen asymptomatic participants were positioned prone on an isokinetic dynamometer with the knee extended and ankle at 90. flexion. US was used to assess AT-length, cross-sectional area (CSA), and AT-elongation during isometric plantarflexion contraction. The intra-rater reproducibility was assessed by ICC (2.1), Test-Retest Variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]), and Standard-Error of Measurement (SEM).
 RESULTS: Measurements of AT-length demonstrated an ICC of 0.93, TRV of 4.5 +/- 3.9%, Bias +/- LoA of -2.8 +/- 25.0 mm and SEM of 6.6 mm. AT-CSA showed an ICC of 0.79, TRV of 8.7 +/- 9.6%, Bias +/- LoA of 1.7 +/- 19.4 mm(2) and SEM of 5.3 mm(2). AT-elongation revealed an ICC of 0.92, TRV of 12.9 +/- 8.9%, Bias +/- LoA of 0.3 +/- 5.7 mm and SEM of 1.5 mm.
 CONCLUSIONS: The presented methodology allows a reproducible assessment of Achilles tendon structural properties when performed by a single rater.
KW  - Ultrasonography
KW  - Achilles tendon
KW  - reproducibility
KW  - isokinetic
Y1  - 2015
U6  - https://doi.org/10.3233/IES-150586
SN  - 0959-3020
SN  - 1878-5913
VL  - 23
IS  - 4
SP  - 263
EP  - 270
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - THES
A1  - Müller, Steffen
T1  - Die belastungsspezifische neuromuskuläre Antwort bei Athleten mit Tendinopathie der Achilles- oder Patellarsehne : Analysen der funktionalen und therapeutischen Effekte eines sensomotorischen Trainings
T1  - Neuromuscular response to physical stress in athletes with tendinopathie of the achilles- or patellartendon : funktional and therapeutic effects of an sensorimotor training
N2  - Tendinopathien der Achilles- oder Patellarsehne sind häufig in Sportarten mit zahlreichen repetitiven Belastungen im Dehnungs-Verkürzungs-Zyklus der unteren Extremität zu finden. Sowohl eine möglicherweise alterierte belastungsspezifische neuromuskuläre Antwort (NMA), als auch funktional begründete Therapiemaßnahmen mit möglichen positiven Effekten sind aktuell ungeklärt. Ziel der Arbeit war deshalb die Untersuchung der belastungsspezifischen neuromuskulären Antwort bei Athleten mit Tendinopathie der Achilles- oder Patellarsehne im Vergleich zu beschwerdefreien Athleten. Zusätzlich sollten mögliche funktionale und therapeutische Effekte eines sensomotorischen Trainings im randomisierten, kontrollierten und prospektiven Studiendesign überprüft werden. 51 Sportler mit unilateraler Tendinopathie (Achilles-/Patellarsehne n = 35/16) und 33 gesunde Sportler wurden zur Beurteilung der belastungsspezifischen neuromuskulären Antwort eingeschlossen. Zur Klärung der Effekte eines sensomotorischen Trainings im Längsschnitt konnten 26 Sportler mit Tendinopathie randomisiert zu einer Kontrollgruppe (n = 14) und einer Therapiegruppe mit sensomotorischem Training (n = 12) zugeordnet werden. Nach einer ersten biomechanischen Messung M1 (Belastungssituationen: Lauf-, Stabilisations-, Kraftbelastung) und der Erhebung der subjektiven Schmerzsymptomatik folgte eine 8-wöchige Therapiephase mit einer abschließenden Re-Test-Messung M2 identisch zu M1. Das sensomotorische Training war auf die gesamte untere Extremität ausgerichtet und wurde nach Einweisung regelmäßig kontrolliert. Die Erfassung der NMA erfolgte über die Quantifizierung der muskulären Aktivität (EMG). Zusätzlich wurde die Kinetik (z.B. Maximalkraft) belastungsspezifisch erfasst. Eine reduzierte NMA konnte für die Sportler mit Tendinopathie über veränderte EMG-Zeit- und Amplitudenmessgrößen, eine reduzierte aktive Stabilisationsfähigkeit und Maximalkraft (p < 0,05) nachgewiesen werden. In Abhängigkeit der Lokalisation (Achilles-/Patellarsehen) bzw. der Seite (Beschwerdeseite/gesunde Seite) ergaben sich keine relevanten Differenzen. Das sensomotorische Training zeigte eine Optimierung der NMA (z.B. erhöhte Maximalkraft) bei Tendinopathie der Achilles- oder Patellarsehne. Die Überprüfung der Beschwerdesymptomatik wies in allen Schmerz-Scores nach der Therapie reduzierte Werte und damit einen positiven therapeutischen Effekt gegenüber der Kontrollgruppe auf. Zusammenfassend kann eine systematisch reduzierte NMA bei Lauf-, Stabilisations- und Kraftbelastung der Sportler mit Tendinopathie nachgewiesen werden. Das sensomotorische Training ist funktional und therapeutisch als effiziente Therapiemaßnahme zu erachten.
N2  - Tendinopathies of the achilles- or patellartendon are common overuse unjuries in sports including high numbers of repetitive stretch-shortening-cycles of the lower limb. Possible alterations of the neuromuscular response (NMR) to physical stress and functionally justified therapies with potential positive effects are currently unknown. The aim of the study was therefore the analysis of the neuromuscular response in situations with physical stress in athletes with tendinopathie of the achilles or patellartendon compared to symptom free athletes. In addition, possible functional and therapeutic effects of a sensorimotor training were studied in a prospective, randomized and controlled study. 51 athletes with unilateral tendinopathy (achilles-/patellartendon n = 35/16) and 33 healthy athletes were included to assess the stress related neuromuscular response (NMR). To clarify the effects of a sensorimotor training 26 athletes with tendinopathy were randomized to a control group (n = 14) and a therapy group with sensorimotor training (n = 12). After initial biomechanical measurements M1 (situations: running, active postural stability and maximum strength test) and the collection of subjective complaints (pain) an 8-week treatment phase followed with a final re-test M2 measure identical to M1. The sensorimotor training was arranged for the entire lower extremity, and was checked after an initial briefing on a regular basis. The assessment of the NMR was quantified by muscle activity (EMG). In addition, the kinetics (e.g. maximum force) was acquired in the stabilization and maximum strength test. A reduced NMR could be proven for athletes with tendinopathy with changed EMG time and amplitude measurements, a reduced active postural stabilization ability and reduced maximum strength (p <0.05). No relevant differences could be observed in comparing localization (achilles-/patellartendon) and side (leg with complains/healthy leg). The sensorimotor training showed an optimization of NMR (e.g. increased maximum strength) for patient with tendinopathy of the achilles- or patellartendon. The examination of the complaints showed reduced values in all pain scores after therapy. The treatment had therefore positive therapeutic effects compared to the control group. In summary, a systematically reduced NMR in running, stabilization and strength tests are evident for athletes with tendinopathy. The sensorimotor training can be considered as an efficient treatment with functional and therapeutic effects.
KW  - Tendinopathie
KW  - neuromuskuläre Kontrolle
KW  - sensomotorisches Training
KW  - Reliabilität
KW  - tendinopathy
KW  - neuromuscular control
KW  - sensorimotor training
KW  - reproducibility
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-16454
SN  - 978-3-940793-18-8
PB  - Universitätsverlag Potsdam
CY  - Potsdam
ER  -