Refine
Year of publication
Document Type
- Doctoral Thesis (3276)
- Article (1927)
- Book (24)
- Conference Proceeding (17)
- Course Material (6)
- Report (6)
- Final Thesis (5)
- Part of a Book (1)
- Habilitation (1)
Language
- English (2685)
- German (2574)
- Multiple languages (4)
Is part of the Bibliography
- no (5263)
Keywords
- - (1164)
- Sepsis (83)
- Staphylococcus aureus (59)
- Plasma (45)
- Diabetes mellitus (38)
- Epidemiologie (37)
- SHIP (34)
- Proteomanalyse (33)
- Depression (31)
- proteomics (31)
Institute
- Institut für Biochemie (280)
- Institut für Physik (275)
- Kliniken und Polikliniken für Innere Medizin (265)
- Institut für Pharmazie (219)
- Abteilung für Mikrobiologie und Molekularbiologie (206)
- Institut für Community Medicine (200)
- Institut für Hygiene und Umweltmedizin (151)
- Zoologisches Institut und Museum (151)
- Institut für Botanik und Landschaftsökologie & Botanischer Garten (148)
- Klinik und Poliklinik für Neurologie (148)
- Institut für Geographie und Geologie (146)
- Institut für Psychologie (145)
- Institut für Diagnostische Radiologie und Neuroradiologie (135)
- Institut für Pharmakologie (134)
- Klinik für Anästhesiologie und Intensivmedizin (131)
- Klinik für Psychiatrie und Psychotherapie (113)
- Poliklinik für Kieferorthopädie, Präventive Zahnmedizin und Kinderzahnheilkunde (108)
- Institut für Anatomie und Zellbiologie (103)
- Klinik und Poliklinik für Frauenheilkunde u. Geburtshilfe (100)
- Klinik und Poliklinik für Orthopädie und Orthopädische Chirurgie (100)
- Klinik und Poliklinik für Kinder- und Jugendmedizin (95)
- Poliklinik für Zahnerhaltung, Parodontologie und Endodontologie (95)
- Institut für Mathematik und Informatik (88)
- Klinik und Poliklinik für Chirurgie Abt. für Viszeral-, Thorax- und Gefäßchirurgie (87)
- Institut für Mikrobiologie - Abteilung für Genetik & Biochemie (85)
- Institut für Klinische Chemie und Laboratoriumsmedizin (77)
- Klinik und Poliklinik für Chirurgie Abt. für Unfall- und Wiederherstellungschirurgie (77)
- Institut für Immunologie u. Transfusionsmedizin - Abteilung Immunologie (75)
- Interfakultäres Institut für Genetik und Funktionelle Genomforschung (MNF) (73)
- Klinik und Poliklinik für Augenheilkunde (73)
- Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie/Plastische Operationen (68)
- Institut für Med. Biochemie u. Molekularbiologie (67)
- Wirtschaftswissenschaften (60)
- Friedrich-Loeffler-Institut für Medizinische Mikrobiologie (59)
- Institut für Medizinische Psychologie (54)
- Klinik und Poliklinik für Hals-, Nasen-, Ohrenkrankheiten, Kopf- und Halschirurgie (51)
- Klinik und Poliklinik für Innere Medizin Abt. Gastroenterologie, Endokrinologie und Ernährungsmedizin (50)
- Institut für Immunologie u. Transfusionsmedizin - Abteilung Transfusionsmedizin (49)
- Klinik und Poliklinik für Urologie (49)
- Poliklinik für zahnärztliche Prothetik und Werkstoffkunde (48)
- Interfakultäres Institut für Genetik und Funktionelle Genomforschung (UMG) (46)
- Klinik und Poliklinik für Neurochirurgie (45)
- Institut für Pathologie (41)
- Klinik und Poliklinik für Hautkrankheiten (35)
- Universitätsmedizin (34)
- Institut für Epidemiologie u. Sozialmedizin (33)
- Institut für Physiologie (33)
- Institut für Erziehungswissenschaft (32)
- Institut für Politik- und Kommunikationswissenschaft (25)
- Rechtswissenschaften (25)
- Institut für Pathophysiologie (24)
- Zentrum für Zahn-, Mund- und Kieferheilkunde (22)
- Institut für Rechtsmedizin (21)
- Institut für Biometrie und Medizinische Informatik (20)
- Institut für Humangenetik (20)
- Historisches Institut (18)
- Institut für Baltistik (18)
- Institut für Philosophie (17)
- Klinik und Poliklinik für Kinderchirurgie (17)
- Klinik und Poliklinik für Innere Medizin Abt. Nephrologie, Hochdruckkrankheiten und Dialyse (16)
- Institut für Anglistik/Amerikanistik (15)
- Institut für Deutsche Philologie (14)
- Klinik und Poliklinik für Chirurgie (14)
- Caspar-David-Friedrich-Institut (13)
- Institut für Ethik und Geschichte der Medizin (13)
- Institut für Fennistik und Skandinavistik (13)
- Mathematisch-Naturwissenschaftliche Fakultät (12)
- Klinik für Herz-, Thorax- und Gefäßchirurgie - Klinikum Karlsburg (11)
- Institut für Slawistik (9)
- Institut für Geologische Wissenschaften (8)
- Institut für Geschichte der Medizin (bis 2014) (8)
- Philosophische Fakultät (8)
- Rechts- und Staatswissenschaftliche Fakultät (7)
- Theologie (7)
- Klinik und Poliklinik für Nuklearmedizin (5)
- Klinik und Poliklinik für Strahlentherapie (2)
- Romanistik am Institut für Fremdsprachliche Philologien (2)
- Theologische Fakultät (2)
- Institut für Altertumswissenschaften (1)
- Institut für Pflegewissenschaft und Interprofessionelles Lernen (1)
Publisher
- MDPI (568)
- Frontiers Media S.A. (364)
- Wiley (223)
- S. Karger AG (158)
- Springer Nature (137)
- IOP Publishing (75)
- De Gruyter (62)
- BioMed Central (BMC) (59)
- SAGE Publications (50)
- Nature Publishing Group (39)
Cerebral cavernous malformation (CCM) is a neurovascular disease that can lead to seizures and stroke-like symptoms. The familial form is caused by a heterozygous germline mutation in either the CCM1, CCM2, or CCM3 gene. While the importance of a second-hit mechanism in CCM development is well established, it is still unclear whether it immediately triggers CCM development or whether additional external factors are required. We here used RNA sequencing to study differential gene expression in CCM1 knockout induced pluripotent stem cells (CCM1−/− iPSCs), early mesoderm progenitor cells (eMPCs), and endothelial-like cells (ECs). Notably, CRISPR/Cas9-mediated inactivation of CCM1 led to hardly any gene expression differences in iPSCs and eMPCs. However, after differentiation into ECs, we found the significant deregulation of signaling pathways well known to be involved in CCM pathogenesis. These data suggest that a microenvironment of proangiogenic cytokines and growth factors can trigger the establishment of a characteristic gene expression signature upon CCM1 inactivation. Consequently, CCM1−/− precursor cells may exist that remain silent until entering the endothelial lineage. Collectively, not only downstream consequences of CCM1 ablation but also supporting factors must be addressed in CCM therapy development.
Zerebrale kavernöse Malformationen (CCMs) sind Gefäßfehlbildungen im Gehirn oder Rückenmark und können sich klinisch aufgrund einer erhöhten Blutungsbereitschaft mit Kopfschmerzen, Gefühls- und Sprachstörungen bis hin zu Krampfanfällen äußern. Sie treten sporadisch oder im Rahmen einer autosomal-dominant erblichen Form auf. Kausale Sequenzveränderungen sind dabei in den drei Genen CCM1, CCM2 und CCM3 bekannt. Die Detektionsrate für pathogene Varianten ist mit bis zu 60 % für sporadische Fälle und mit weit über 90 % für familiäre Fälle sehr hoch. Während Genpanel-Analysen sehr verlässlich Einzelnukleotidveränderungen, kleine Insertions- und Deletionsvarianten sowie Kopienzahlveränderungen detektieren können, werden komplexe Strukturvarianten oder Veränderungen in nicht-kodierenden Regionen kaum erfasst. Diese rücken jedoch für die bisher genetisch unaufgeklärten Fälle immer mehr in den Fokus des Interesses. Diese Arbeit adressiert daher zum einen die Identifizierung neuer Strukturvarianten und deren funktionale Interpretation im Kontext der CCM-Erkrankung.
Im Rahmen der vorliegenden Arbeit ist der erstmalige Nachweis einer interchromosomalen Insertion bei einem CCM-Patienten gelungen. Die unbalancierte Insertion genomischen Materials von Chromosom 1 in die kodierende Region des CCM2-Gens konnte durch die Verbindung von bioinformatischen Auswertestrategien der Next Generation Sequencing-Genpanel-Daten, molekularzytogenetischen Analysen und einer molekularen Bruchpunktkartierung genau charakterisiert werden. Die Identifikation einer weiteren Strukturvariante, einer Deletion des Transkriptionsstarts von CCM1, verdeutlichte die Herausforderungen bei der Bewertung von Veränderungen in nicht-kodierenden Genbereichen. Für eine eindeutige Klassifikation der Variante wurden daher funktionale Analysen durchgeführt, die auf einer CRISPR/Cas9-vermittelten Nachbildung der Deletion in iPSCs und der anschließenden Differenzierung in Endothelzellen beruhte. Damit konnte gezeigt werden, dass die Deletion zu einem Verlust der CCM1 mRNA- und Proteinexpression führt. Zudem wurde in den differenzierten Endothelzellen eine für die CCM-Pathogenese charakteristische Deregulation von KLF2, THBS1, NOS3 und HEY2 beobachtet. Schließlich war es auf Basis dieser in vitro-Analysen möglich, die Variante entsprechend den ACMG-Richtlinien als wahrscheinlich pathogen zu bewerten und somit die molekulare CCM-Diagnose zu sichern.
Die Verbindung des CRISPR/Cas9-Systems mit iPSCs ist nicht nur für die Variantenbewertung von großem Nutzen, sondern bietet auch das Potential zum besseren Verständnis von Krankheitsmechanismen. Ein weiterer Fokus der vorliegenden Arbeit lag daher auf der Etablierung und Verwendung iPSC-basierter Zellkulturmodelle für die CCM-Modellierung. Zunächst ist es gelungen, mehrere iPSC-Linien mit einer kompletten CRISPR/Cas9-vermittelten CCM1-, CCM2- oder CCM3-Inaktivierung zu generieren. Diese wurden anschließend für die Differenzierung in hBMEC-ähnliche Zellen und innovative dreidimensionale vaskuläre Organoide verwendet. In diesen Systemen konnte beispielsweise eindrücklich eine tumorähnliche Proliferation CCM3-defizienter Endothelzellen nachvollzogen werden, die nur in Kontakt mit Wildtyp-Zellen auftrat. RNA-Sequenzierungen in einem CCM1-basierten Knockout-Modell konnten darüber hinaus die Rolle von CCM1 als Endothel-spezifisches Suppressorgen stärken. Die im Rahmen der Arbeit etablierten Systeme werden zukünftig für weitere Fragestellungen der CCM-Pathogenese wie der endothelialen Barrierestörung eingesetzt und stellen darüber hinaus sehr gut geeignete Plattformen für die effektive Entwicklung dringend benötigter therapeutischer Ansätze dar.
The Flavivirus genus (Flaviviridae family) comprises the most important arboviruses in the world such as dengue virus, West Nile virus (WNV), Zika virus (ZIKV), Japanese encephalitis virus and yellow fever virus (YFV). Every year, several outbreaks caused by flaviviruses are reported worldwide (i.e.: ZIKV and YFV outbreaks in South America) with a huge impact on economy and public health. In the last few decades, many aspects of the flavivirus biology and the interaction of flaviviruses with host cells have been elucidated. However, many underlying mechanisms concerning receptor usage, entry process and viral interaction with host cell factors are still not completely understood. Integrins, the major class of cell adhesion molecules have been implicated in the infectious cycle of different viruses including flaviviruses. A previous report proposed that a particular integrin, the αVβ3 integrin, might act as a cellular receptor for WNV. However, this hypothesis was not confirmed by other groups. In the present study, murine cell lines lacking the expression of one or more integrin subunits were used to evaluate the involvement of different integrins in the flavivirus infection cycle. Mouse fibroblasts lacking the expression of β1 integrin (MKF-β1-/-) or β3 integrin (MEF-β3-/-) subunits or αVβ3 integrin (MEF-αVβ3-/-) as well as their corresponding wild-type cells were utilized. A second model using Chinese hamster ovary cells (CHO-K1), a cell line that has been described to be refractory to some flaviviruses, were modified to express either αV (CHO-αV+/+) or β3 (CHO-β3+/+) integrin subunits. All cell lines were first characterized by confocal laser microscopy, flow cytometry and functional assays prior to infection to assess their integrin expression. The cell lines were then inoculated with different flaviviruses of public health relevance: WNV, YFV-17D, Usutu virus (USUV), Langat virus (LGTV) and ZIKV. Infection assays were designed in order to evaluate whether integrins influence i) cell susceptibility; ii) binding; iii) internalization and iv) replication of the investigated flaviviruses. Our findings clearly demonstrate that β1, β3 and αVβ3 integrins do not act as flavivirus cellular receptor or attachment factor since their ablation does not completely abrogate flavivirus infection in the investigated cell lines. Flavivirus binding to the cell surface of MEFs, MKFs and CHO cells was not disturbed by the genomic deletion of the above-mentioned integrins. The deletion of β1 and β3 integrin subunit did not affect internalization of any of the flaviviruses tested. In contrast to that, loss of αVβ3 integrin in the MEF-αVβ3-/- cells showed a statistically significant decrease in WNV and USUV internalization while ZIKV, YFV-17D and LGTV internalization remained unaffected suggesting that αVβ3 integrin might be involved in the internalization process of at least some flaviviruses. On the other hand, flavivirus replication was substantially impaired in the integrin-deficient cell lines in comparison to their corresponding wild-type cells. Both, MEF-β3-/- and MKF-β1-/- cells showed a statistically significant reduction on viral load for all flaviviruses tested in comparison to their respective wild-type cells. The MEF-αVβ3-/- cells in particular, showed a strong inhibition of flavivirus replication with a reduction of up to 99% on viral loads for all flaviviruses tested. Levels of flavivirus negative-strand RNA were substantially decreased in MEF-αVβ3-/- cells indicating that integrins might influence flavivirus RNA replication. The ectopic expression of either αV or β3 integrin subunits in CHO cells slightly increased the replication of all flaviviruses tested. Taken together, this is the first report highlighting the involvement of integrins in ZIKV, USUV, LGTV and YFV infection. The results strongly indicate that the investigated integrins play an important role in flavivirus infection and might represent a novel host cell factor that enhances flavivirus replication. Although the exact mechanism of interaction between integrins and flaviviruses is currently unknown, the results provided in this study deepen our insight into flavivirus - host cell interactions and open doors for further investigations.
Background: Alveolar soft-part sarcoma (ASPS) is a rare sarcoma often occurring in young patients that is characterized by the unbalanced translocation der(17)t(X;17) (p11;q25). Although itusuallyshowsan indolent clinical course, the prognosis is usually poor in advanced disease. Since standard chemotherapy regimens used in soft-tissue sarcomas lack efficacy in ASPS, new therapeutic options are needed. We investigated the efficacy of trabectedin, which has demonstrated activity in a variety of cancer types including some of the most prevalent translocation-related sarcomas. Patients and Methods: 7 patients with metastatic or advanced ASPS treated with trabectedin in the Sarcoma Center Berlin-Brandenburg and the University Hospital of Greifswald were analyzed for median progression-free survival (mPFS), overall survival (OS), and therapy-related toxicity. Results: In 6 patients with documented disease progression, disease stabilization was reached with trabectedin; only 1 patient experienced progressive disease. The mPFS and OS were 7 months and 21 months, respectively, since the start of trabectedin treatment. Overall, no severe Common Toxicity Criteria (CTC) grade 3 or 4 toxicity was observed. Conclusions: The poor prognosis of patients with ASPS has so far been due to the unavailability of effective systemic treatments. Trabectedin can be considered the only currently registered drug with clinical activity in this disease.
Objective: Epithelioid sarcoma (ES) presents unique clinical features in comparison to other sarcoma subtypes. Data regarding the benefits of chemotherapy are very limited. Combination regimens using gemcitabine and docetaxel (Gem/Doce) have proven to be effective, especially in uterine and nonuterine leiomyosarcoma. Yet, there is no available data on the efficacy of Gem/Doce in ES. Methods: A retrospective analysis of the three participating institutions was performed. Twenty-eight patients with an ES diagnosis presented at one of the participating institutions between 1989 and 2012. Of this group, 17 patients received chemotherapy. Results: Patients' median overall survival (OS) after the beginning of palliative chemotherapy was 21 months, and the 1-year OS was 87%. Twelve patients received Gem/Doce with a clinical benefit rate of 83%. The median progression-free survival (PFS) was 8 months for all patients receiving Gem/Doce. The best response was complete remission in 1 patient and partial remission in 6 patients. All 6 patients receiving Gem/Doce as a first-line treatment showed measurable responses with a median PFS of 9 months. Conclusions: In this retrospective study, Gem/Doce was an effective chemotherapeutic regimen for ES. Prospective studies are needed to better assess the effects of this combination drug therapy.
Die at-line Expressionsanalyse von Bioprozess-relevanten Markergenen auf der Grundlage von elektrischen Biochip-Verfahren ist eine viel versprechende Strategie für eine prozessbegleitende Beurteilung der Zellphysiologie des Produktionswirtes. Eine derartige direkte Methode für die Bestimmung des physiologischen Status würde zu einer umfassenderen Überwachung und Kontrolle von industriellen Fermentationsprozessen beitragen. Die Expressionsanalyse der Markergene mit den verwendeten elektrischen Biochips beruht auf dem Nachweis der entsprechenden mRNA über eine Sandwich-Hybridisierung und der elektrochemischen Detektion der Hybride. Hierbei sind sowohl Bead-basierte als auch Array-basierte Formate möglich. Der Bead-basierte mRNA-Nachweis nutzt paramagnetische Partikel (Beads) für die Immobilisierung von Gen-spezifischen Fängersonden. Während der Hybridisierung wird die nachzuweisende mRNA auf den Beads gebunden. Gleichzeitig hybridisiert eine Detektionssonde in einem anderen Bereich der mRNA und ermöglicht so die Markierung mit einem Enzym. Dieses setzt para-Aminophenol (pAP) frei, das an den Elektroden des Biochips über zyklische Oxidations- und Reduktionsprozesse (Redox-Recycling) amperometrisch detektiert wird. Der resultierende elektrische Strom dient als Maß für die mRNA-Menge in der Probe. Die Array-basierte mRNA-Detektion nutzt elektrische Biochips mit 16 individuell auslesbaren Elektrodenpositionen. In diesem Format werden die Fängersonden direkt auf der Elektrodenoberfläche immobilisiert. Durch die Hybridisierung wird die nachzuweisende mRNA auf den jeweiligen Elektrodenpositionen gebunden. Die Detektion erfolgt positionsspezifisch über das Enzym-kontrollierte Redox-Recycling von pAP. Der Fokus der vorliegenden Arbeit lag vor allem auf der Verkürzung, Optimierung und Automation der Bead-basierten mRNA-Detektion. Durch erste Optimierungen einzelner Protokollschritte der Bead-basierten Sandwich-Hybridisierung konnte eine Verkürzung des Protokolls von ursprünglich 4 h auf unter 3 h erzielt werden. Der Übergang zu einer Sandwich-Hybridisierung in Lösung führte vor allem zu einer verbesserten Handhabbarkeit und Reproduzierbarkeit des Protokolls. Die Neuanordnung der Sondenbindestellen auf der Ziel-mRNA und die Einführung einer zweiten Detektionssonde resultierten in signifikanten Steigerungen der Hybridisierungssignale. Dies ermöglichte eine Verkürzung der Detektionszeit auf ca. 75 min. Durch weitere Optimierungen einzelner Aspekte des Protokolls konnte schließlich eine mRNA-Detektionszeit von ca. 45 min realisiert werden. Somit wurde das Protokoll für die Bead-basierte mRNA-Detektion mit dem elektrischen Biochip, ausgehend von isolierter Gesamt-RNA, von ursprünglich 4 h auf 45 min verkürzt. Gleichzeitig konnte die Sensitivität des Protokolls um das etwa Fünffache gesteigert werden. Die Automatisierung mithilfe eines Pipettierroboters erlaubte eine parallele Bearbeitung und die automatische, sequentielle Detektion von 8 Proben innerhalb von ca. 1 h. Weiterhin wurde die Array-basierte mRNA-Detektion etabliert und teilweise optimiert. Dies ermöglichte eine parallele, elektrochemische Detektion von derzeit 4 verschiedenen mRNAs in einer Probe isolierter Gesamt-RNA innerhalb von 20 min. Allerdings sind vor der automatischen Messung noch zusätzliche Schritte für die manuelle Bearbeitung der RNA-Proben (ca. 25 min) erforderlich. Die Anwendbarkeit der entwickelten Protokolle wurde jeweils am Beispiel von ausgewählten Markergenen des industriell bedeutsamen Wirtes Bacillus licheniformis getestet. Die mithilfe der elektrischen Biochip gemessenen Expressionsprofile der Markergene korrelierten mit den mittels real-time RT-PCR bestimmten mRNA-Mengen. Somit konnte im Rahmen der vorliegenden Dissertation die Grundlage für eine Bioprozess-begleitende mRNA-Analytik, basierend auf elektrischen Biochips, geschaffen werden.
Androgene sind bei Männern und Frauen hochkomplex in die Regulation des humanen
Metabolismus involviert, prägen in beträchtlichem Ausmaß die Körpermorphologie und können bei
Dysregulation in zahlreichen Erkrankungen resultieren. Jedoch ist die Rolle der Androgene auf den
Metabolismus bisher nicht vollständig erforscht und auch die detaillierten Mechanismen der
Interaktion sowie die abschließende Bedeutung für die Entstehung von Krankheiten sind
größtenteils unklar. Ziel der vorliegenden Arbeit war daher, mit Hilfe der Metabolomik - der
Bestimmung molekularer Stoffwechselzwischen- und endprodukte - einen Beitrag zum besseren
Verständnis der Wechselwirkungen zwischen dem Androgenhaushalt und Metabolismus zu leisten.
Die Datengrundlage der vorliegenden Arbeit wird aus einer Studienpopulation bestehend aus 430
Männern und 343 Frauen in einem Alter zwischen 20 und 79 Jahren gebildet, welche im Rahmen
der populationsbasierten Querschnittsstudie SHIP-TREND rekrutiert wurden. Unter Verwendung
von massenspektrometrischen Messmethoden und durch lineare Regressionsmodelle wurden
Assoziationen zwischen den Androgenen Testosteron, Androstendion und
Dehydroepiandrosteronsulfat beziehungsweise dem Transportprotein SHBG (sexual hormonebinding globulin) und Metaboliten aus Plasma und Urin identifiziert und anschließend ausgewertet.
Die Analysen offenbarten eine deutliche geschlechtsspezifische Differenz in Androgen-assoziierten
Metaboliten, beispielsweise bezüglich Urat, verschiedenen Lipiden und zahlreichen
Surrogatparametern für Lebensstilfaktoren, wie Piperin, Cotinin oder Trigonellin. Auffallend ist
hierbei, dass, im Vergleich zu Männern, Androgene bei Frauen, insbesondere bei Betrachtung von
postmenopausalen Frauen, eine deutlich stärkere Assoziation mit Metabolitkonzentrationen in
Plasma und Urin zeigten. Besonders deutlich wurde dieses Phänomen bei Untersuchungen
zwischen Dehydroepiandrosteronsulfat und verschiedenen Lipidderivaten. Letzterem ist eine
besonders hohe klinische Bedeutung beizumessen, da sich Veränderungen im Androgenhaushalt
bei Frauen häufig im Zusammenhang mit metabolischen und kardiovaskulären Erkrankungen
präsentieren. Weiterhin konnte in der vorliegenden Arbeit eine neuartige Beobachtung bezüglich
der Assoziation zwischen Androstendion und dem Metabolismus biogener Amine, wie Dopamin
oder Serotonin, dokumentiert werden. Überraschend war die geringe Überschneidung von
Androgen-assoziierten Metaboliten, insbesondere Dehydroepiandrosteron, über die Geschlechter
hinweg.
Die Ergebnisse dieser Arbeit liefern neue Einblicke in die Interaktion zwischen Androgenen und dem
humanen Metabolismus und ermöglichen es, insbesondere für den weiblichen Stoffwechsel,
Rückschlüsse zu ziehen sowie etwaige klinische Fragestellungen zukünftig in isolierten Studien zu
untersuchen.
Abstract
Differentiation of cardiac progenitor cells (CPC) into cardiomyocytes is a fundamental step in cardiogenesis, which is marked by changes in gene expression responsible for remodeling of the cytoskeleton and in altering the mechanical properties of cells. Here we have induced the differentiation of CPC derived from human pluripotent stem cells into immature cardiomyocytes (iCM) which we compare with more differentiated cardiomyocytes (mCM). Using atomic force microscopy and real‐time deformability cytometry, we describe the mechanodynamic changes that occur during the differentiation process and link our findings to protein expression data of cytoskeletal proteins. Increased levels of cardiac‐specific markers as well as evolution of cytoskeletal morphology and contractility parameters correlated with the expected extent of cell differentiation that was accompanied by hypertrophic growth of cells. These changes were associated with switching in the balance of the different actin isoforms where β‐actin is predominantly found in CPC, smooth muscle α‐actin is dominant in iCM cells and sarcomeric α‐actin is found in significantly higher levels in mCM. We link these cytoskeletal changes to differences in mechano‐dynamic behavior of cells that translate to changes in Young's modulus that depend on the cell adherence. Our results demonstrate that the intracellular balance of actin isoform expression can be used as a sensitive ruler to determine the stage of differentiation during early phases of cardiomyocyte differentiation that correlates with an increased expression of sarcomeric proteins and is accompanied by changes in cellular elasticity.
The Common Tern (Sterna hirundo) is one of Germany’s farthest migrating bird species. Ringing studies have shown the use of the East Atlantic flyway, and according to their main wintering areas at the western and southern African coasts, German and European Common Tern populations have been divided into two allohiemic groups. However, first ring recoveries of German Common Terns in Israel indicated that some of the birds breeding in eastern Germany cross central Europe and migrate along the eastern African coast. To investigate the migratory behavior of Common Terns from East Germany, we fitted 40 Common Terns breeding in a colony at the German Baltic coast with light-level geolocators. Twenty-four loggers with analyzable datasets could be retrieved, revealing two different migratory strategies within one population. Seventeen individuals (70.83%) used the eastern Atlantic flyway and spent the winter at the western African coast, the Gulf of Guinea and the southern African coast, while the other individuals (n = 7; 29.17%) crossed central Europe, migrated along the eastern African coast and overwintered in the Mozambique Channel and South African coast. We, therefore, suggest to add a third allohiemic group to complement the picture of European Common Tern migration. Moreover, our results provide new knowledge and open new questions, which can be used for future studies regarding the evolution of different migratory strategies and its consequences in relation to climate change.
Obesity and diabetes have reached epidemic proportions and have emerged as massive public health problems globally. The etiology of both obesity and diabetes are related, multifactorial, highly complex, and involves interplay of genetic, environmental, socio-economic and physiological factors, which calls for a more extensive research in understanding the risk factors and biological pathways. Hence, this dissertation contributed in part to understanding the role of iron markers in the development of type 2 diabetes mellitus and the role of intrauterine hyperglycemia in influencing the risk of offspring obesity along with investigating potential pathways.
In the first part of my dissertation, the associations of iron markers (ferritin and transferrin) with type 2 diabetes mellitus and metabolic syndrome were investigated using the population-based Study of Health in Pomerania. The present analyses were based on 3,232 participants aged 20-81 years with a follow-up time of nearly 11 years. The results suggest that serum ferritin concentrations were associated with a higher prevalence of type 2 diabetes mellitus and metabolic syndrome in the total population as well as in men. However, the effects of serum ferritin on incident type 2 diabetes mellitus were observed only in women, while the effects on incident metabolic syndrome were seen in the total population. Serum ferritin is also known to reflect systemic inflammation or hepatic dysfunction in addition to increased iron stores. Hence, upon further analyses, the associations were found to be attenuated after adjustment for hepatic enzymes but not after adjustment for inflammation. Transferrin was not associated with any of the outcomes. Thus, our study provides evidence for a link between the iron marker ferritin and type 2 diabetes mellitus and metabolic syndrome, although the association seemed to vary by sex. Moreover, hepatic dysfunction seems likely to be in the pathway between ferritin and type 2 diabetes mellitus and metabolic syndrome.
In the second part of my dissertation, the association between maternal hyperglycemia and the risk of offspring overweight and obesity were investigated using three different cohorts: TEDDY, TEENDIAB and BABYDIAB/BABYDIET. The present analyses were based on a total of 8,103 children who were followed until 6 years of age in TEDDY study and until 18 years of age in TEENDIAB and BABYDIAB/BABYDIET studies. The dissertation revealed that maternal hyperglycemia in general may be associated with increased risk for childhood overweight and obesity, and that the association gets stronger as children grow older, with the risk being clearly evident at late childhood and adolescence. Moreover, this dissertation adds that this association can be driven by different pathways based on the type of maternal diabetes to which the offspring was exposed. The association of maternal gestational diabetes mellitus with offspring overweight can be largely explained by the confounding influence of maternal BMI, whereas the association of maternal type 1 diabetes mellitus with offspring overweight can be substantially explained by birthweight in all three studies. In our attempt to understand biological pathways at a cellular level, we found that the offspring metabolome was unlikely to be in the causal pathway between maternal type 1 diabetes mellitus and overweight, because this association could not be explained by any of the potentially relevant metabolites.
To conclude, this dissertation acknowledges the fact that prevention and early intervention of obesity and diabetes is of paramount importance to lessen the impact of these public health problems. Thus, our findings of the role of ferritin in increasing the risk of type 2 diabetes mellitus/ metabolic syndrome and the role of intrauterine hyperglycemia in increasing the risk of offspring overweight helped to identify particular risk groups who may need closer attention with respect to prevention of obesity and diabetes.
The Apolipoprotein E (APOE) gene polymorphism (rs429358 and rs7412) shows a well-established association with lipid profiles, but its effect on cardiovascular disease is still conflicting. Therefore, we examined the association of different APOE alleles with common carotid artery intima-media thickness (CCA-IMT), carotid plaques, incident myocardial infarction (MI) and stroke. We analyzed data from 3327 participants aged 20–79 years of the population-based Study of Health in Pomerania (SHIP) from Northeast Germany with a median follow-up time of 14.5 years. Linear, logistic, and Cox-regression models were used to assess the associations of the APOE polymorphism with CCA-IMT, carotid plaques, incident MI and stroke, respectively. In our study, the APOE E2 allele was associated with lower CCA-IMT at baseline compared to E3 homozygotes (β: − 0.02 [95% CI − 0.04, − 0.004]). Over the follow-up, 244 MI events and 218 stroke events were observed. APOE E2 and E4 allele were not associated with incident MI (E2 HR: 1.06 [95% CI 0.68, 1.66]; E4 HR: 1.03 [95% CI 0.73, 1.45]) and incident stroke (E2 HR: 0.79 [95% CI 0.48, 1.30]; E4 HR: 0.96 [95% CI 0.66, 1.38]) in any of the models adjusting for potential confounders. However, the positive association between CCA-IMT and incident MI was more pronounced in E2 carriers than E3 homozygotes. Thus, our study suggests that while APOE E2 allele may predispose individuals to lower CCA-IMT, E2 carriers may be more prone to MI than E3 homozygotes as the CCA-IMT increases. APOE E4 allele had no effect on CCA-IMT, plaques, MI or stroke.
The long-term effectiveness of powered toothbrushes (PTBs) and interdental cleaning aids (IDAs) on a population level is unproven. We evaluated to what extent changes in PTB and IDA use may explain changes in periodontitis, caries, and tooth loss over the course of 17 y using data for adults (35 to 44 y) and seniors (65 to 74 y) from 3 independent cross-sectional surveys of the German Oral Health Studies (DMS). Oaxaca decomposition analyses assessed to what extent changes in mean probing depth (PD), number of caries-free surfaces, and number of teeth between 1) DMS III and DMS V and 2) DMS IV and DMS V could be explained by changes in PTB and IDA use. Between DMS III and V, PTB (adults: 33.5%; seniors: 28.5%) and IDA use (adults: 32.5%; seniors: 41.4%) increased along with an increase in mean PD, number of caries-free surfaces, and number of teeth. Among adults, IDA use contributed toward increased number of teeth between DMS III and V as well as DMS IV and V. In general, the estimates for adults were of lower magnitude. Among seniors between DMS III and V, PTB and IDA use explained a significant amount of explained change in the number of caries-free surfaces (1.72 and 5.80 out of 8.44, respectively) and the number of teeth (0.49 and 1.25 out of 2.19, respectively). Between DMS IV and V, PTB and IDA use contributed most of the explained change in caries-free surfaces (0.85 and 1.61 out of 2.72, respectively) and the number of teeth (0.25 and 0.46 out of 0.94, respectively) among seniors. In contrast to reported results from short-term clinical studies, in the long run, both PTB and IDA use contributed to increased number of caries-free healthy surfaces and teeth in both adults and seniors.
Aim
This study aimed to identify the factors influencing the changes in the number of teeth present and the number of healthy or filled surfaces between two time points.
Materials and Methods
Repeated cross-sectional data from population-based studies, namely the German Oral Health Studies (DMS-III vs. DMS-V), the Studies of Health in Pomerania (SHIP-START-0 vs. SHIP-TREND-0), and the Jönköping study (2003 vs. 2013), were analysed. Oaxaca decomposition models were constructed for the outcomes (number of teeth, number of healthy surfaces, and number of filled surfaces).
Results
The number of teeth increased between examinations (DMS: +2.26 [adults], +4.92 [seniors], SHIP: +1.67, Jönköping: +0.96). Improvements in education and dental awareness brought a positive change in all outcomes. An increase in powered toothbrushing and inter-dental cleaning had a great impact in DMS (adults: +0.25 tooth, +0.78 healthy surface, +0.38 filled surface; seniors: +1.19 teeth, 5.79 healthy surfaces, +0.48 filled surface). Inter-dental cleaning decreased by 4% between SHIP-START-0 and SHIP-TREND-0, which negatively affected the outcomes.
Conclusions
From this study, it can be concluded that education may be the most important factor having a direct and indirect effect on the outcomes. However, for better oral health, powered toothbrushing and inter-dental cleaning should not be neglected.
Individual responses to behavioral treatment of anxiety disorders vary considerably, which requires a better understanding of underlying processes. In this study, we examined the violation and change of threat beliefs during exposure. From 8,484 standardized exposure records of 605 patients with different anxiety disorders, learning indicators were derived: expectancy violation as mismatch between threat expectancy before exposure and threat occurrence, expectancy change as difference between original and adjusted expectancy after exposure, and prediction-error learning rate as extent to which expectancy violation transferred into change. Throughout sessions, high threat expectancy but low occurrence and adjusted expectancy indicated successful violation and change of threat beliefs by exposure. Expectancy violation, change, and learning rate substantially varied between patients. Not expectancy violation itself, but higher learning rate and expectancy change predicted better treatment outcome. Successful exposure thus requires expectancy violation to induce actual expectancy change, supporting learning from prediction error as transdiagnostic mechanism underlying successful exposure therapy.
Abstract
Background
The need to optimize exposure treatments for anxiety disorders may be addressed by temporally intensified exposure sessions. Effects on symptom reduction and public health benefits should be examined across different anxiety disorders with comorbid conditions.
Methods
This multicenter randomized controlled trial compared two variants of prediction error‐based exposure therapy (PeEx) in various anxiety disorders (both 12 sessions + 2 booster sessions, 100 min/session): temporally intensified exposure (PeEx‐I) with exposure sessions condensed to 2 weeks (n = 358) and standard nonintensified exposure (PeEx‐S) with weekly exposure sessions (n = 368). Primary outcomes were anxiety symptoms (pre, post, and 6‐months follow‐up). Secondary outcomes were global severity (across sessions), quality of life, disability days, and comorbid depression.
Results
Both treatments resulted in substantial improvements at post (PeEx‐I: dwithin = 1.50, PeEx‐S: dwithin = 1.78) and follow‐up (PeEx‐I: dwithin = 2.34; PeEx‐S: dwithin = 2.03). Both groups showed formally equivalent symptom reduction at post and follow‐up. However, time until response during treatment was 32% shorter in PeEx‐I (median = 68 days) than PeEx‐S (108 days; TRPeEx‐I = 0.68). Interestingly, drop‐out rates were lower during intensified exposure. PeEx‐I was also superior in reducing disability days and improving quality of life at follow‐up without increasing relapse.
Conclusions
Both treatment variants focusing on the transdiagnostic exposure‐based violation of threat beliefs were effective in reducing symptom severity and disability in severe anxiety disorders. Temporally intensified exposure resulted in faster treatment response with substantial public health benefits and lower drop‐out during the exposure phase, without higher relapse. Clinicians can expect better or at least comparable outcomes when delivering exposure in a temporally intensified manner.
Background/Aims
Prematurely born infants undergo costly, stressful eye examinations to uncover the small fraction with retinopathy of prematurity (ROP) that needs treatment to prevent blindness. The aim was to develop a prediction tool (DIGIROP-Screen) with 100% sensitivity and high specificity to safely reduce screening of those infants not needing treatment. DIGIROP-Screen was compared with four other ROP models based on longitudinal weights.
Methods
Data, including infants born at 24–30 weeks of gestational age (GA), for DIGIROP-Screen development (DevGroup, N=6991) originate from the Swedish National Registry for ROP. Three international cohorts comprised the external validation groups (ValGroups, N=1241). Multivariable logistic regressions, over postnatal ages (PNAs) 6–14 weeks, were validated. Predictors were birth characteristics, status and age at first diagnosed ROP and essential interactions.
Results
ROP treatment was required in 287 (4.1%)/6991 infants in DevGroup and 49 (3.9%)/1241 in ValGroups. To allow 100% sensitivity in DevGroup, specificity at birth was 53.1% and cumulatively 60.5% at PNA 8 weeks. Applying the same cut-offs in ValGroups, specificities were similar (46.3% and 53.5%). One infant with severe malformations in ValGroups was incorrectly classified as not needing screening. For all other infants, at PNA 6–14 weeks, sensitivity was 100%. In other published models, sensitivity ranged from 88.5% to 100% and specificity ranged from 9.6% to 45.2%.
Conclusions
DIGIROP-Screen, a clinical decision support tool using readily available birth and ROP screening data for infants born GA 24–30 weeks, in the European and North American populations tested can safely identify infants not needing ROP screening. DIGIROP-Screen had equal or higher sensitivity and specificity compared with other models. DIGIROP-Screen should be tested in any new cohort for validation and if not validated it can be modified using the same statistical approaches applied to a specific clinical setting.
Background
The COVID-19 pandemic and the imposed lockdowns severely affected routine care in general and specialized physician practices.
Objective
To describe the long-term impact of the COVID-19 pandemic on the physician services provision and disease recognition in German physician practices and perceived causes for the observed changes.
Design
Observational study based on medical record data and survey data of general practitioners and specialists' practices.
Participants
996 general practitioners (GPs) and 798 specialist practices, who documented 6.1 million treatment cases for medical record data analyses and 645 physicians for survey data analyses.
Main measures
Within the medical record data, consultations, specialist referrals, hospital admissions, and documented diagnoses were extracted for the pandemic (March 2020–September 2021) and compared to corresponding pre-pandemic months in 2019. The additional online survey was used to assess changes in practice management during the COVID-19 pandemic and physicians' perceived main causes of affected primary and specialized care provision.
Main results
Hospital admissions (GPs: −22% vs. specialists: −16%), specialist referrals (−6 vs. −3%) and recognized diseases (−9 vs. −8%) significantly decreased over the pandemic. GPs consultations initially decreased (2020: −7%) but compensated at the end of 2021 (+3%), while specialists' consultation did not (−2%). Physicians saw changes in patient behavior, like appointment cancellation, as the main cause of the decrease. Contrary to this, they also mentioned substantial modifications of practice management, like reduced (nursing) home visits (41%) and opening hours (40%), suspended checkups (43%), and delayed consultations for high-risk patients (71%).
Conclusion
The pandemic left its mark on primary and specialized healthcare provision and its utilization. Both patient behavior and organizational changes in practice management may have caused decreased and non-compensation of services. Evaluating the long-term effect on patient outcomes and identifying potential improvements are vital to better prepare for future pandemic waves.