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Monozentrische Evaluation des intelligenten Assistenzdienstes OPTINOFA in Bezug auf Prozess- und Qualitätsindikatoren der klinischen Notfallversorgung
No full textGegenwärtig sind deutsche Notaufnahmen regelhaft von Overcrowding betroffen. Einer Situation in der mehr Patienten versorgt werden müssen, als Personal und Ressourcen vorhanden sind. Vor diesem Hintergrund kommt der Steuerung von Patientenströmen eine zentrale Bedeutung zu.
Um eine stringentere Steuerung von Patienten in den ambulanten und stationären Sektor zu erreichen, und so die Notaufnahmen zu entlasten, versucht das Projekt „Optimierung der Notfallversorgung durch strukturierte Ersteinschätzung mittels intelligenter Assistenzdienste“ (OPTINOFA) mittels einem gleichnamigen Software-Tool zur intelligenten Ersteinschätzung sowohl Behandlungsdringlichkeit als auch eine Empfehlung zum Behandlungsort der Patienten strukturiert zu erheben. Die Empfehlung des Behandlungsortes ist bisher nicht Teil der Empfehlungen von etablierten Triage-Tools wie dem weit verbreiteten Emergency Severity Index (ESI).
Daher wurden in dieser Arbeit Prozess- und Qualitätsindikatoren, wie Wartezeit, Verweildauer und Letalität sowie die Übereinstimmungen der Triageempfehlungen zwischen ESI und OPTINOFA monozentrisch in der Notaufnahme der Universitätsmedizin Göttingen untersucht. Die Patienten wurden dabei im Kontrollzeitraum mittels ESI und im Interventionszeitraum mit OPTINOFA und ESI ersteingeschätzt, um die Empfehlungen der unterschiedlichen Triagestufen miteinander zu vergleichen.
Während es bei ESI zu einer klaren Überrepräsentation von Patienten in der Triagestufe 3 kam, verteilte OPTINOFA die Patienten ausgeglichener unter den verschiedenen Triagestufen. Die Analyse der Gründe für die Abweichungen zwischen den Triageempfehlungen von ESI und OPTINOFA im Interventionszeitraum ergab, dass in 57,3% der Fälle eine hinreichende Versorgung in einer kassenärztlichen Bereitschaftspraxis erwartet wurde.
Bei der Untersuchung der Wartezeit aller Patienten, war diese im Interventionszeitraum um 8 min (p < 0,001) reduziert. Bei Betrachtung der verschiedenen Triagestufen miteinander konnte zudem eine signifikante Reduktion der Wartezeit in der Triagestufen 2 (6 min, p < 0,001), Triagestufe 3 (12 min, p < 0,001) und Triagestufe 4 (10 min, p < 0,001), jedoch nicht in den Triagestufen 1 (4 min, p = 0,700 ) und 5 (2 min, p = 0,596) gezeigt werden.
Die Verweildauer der Patienten war mit 8 Minuten (p = 0,190) nicht signifikant reduziert. Die Analyse der Triagestufen ergab, dass nur Patienten der Triagestufe 3 eine signifikant kürzere Verweildauer aufwiesen (9 min, p = 0,015).
Aufgrund geringer Ereigniszahlen konnte über die Veränderung der Letalität in der Notaufnahme der Universitätsmedizin Göttingen keine Aussage getroffen werden.
Diese Arbeit zeigt monozentrisch, dass die Nutzung von OPTINOFA mit einer Reduktion der Wartezeit, jedoch nicht der Verweildauer assoziiert war. Eine signifikante Reduktion der Verweildauer konnte mutmaßlich nicht gezeigt werden, da die Verweildauer, mehr als die Wartezeit, von Faktoren außerhalb der Notaufnahme, wie beispielsweise der Belegung der bettenführenden Stationen abhängig ist. Aus dem Vergleich der beiden Tools im Interventionszeitraum lässt sich ableiten, dass ein Triage-Tool wie OPTINOFA, welches ambulante Behandlungsorte außerhalb der Notaufnahme empfiehlt den Bedarf der Notaufnahmen bei der heutigen Patientenzusammensetzung adäquat abbildet. Zusammenfassend könnte sich die Anwendung von OPTINOFA als vielversprechend in Bezug auf die Verbesserung der Qualitätsindikatoren in der Notaufnahme herausstellen und so konsekutiv die Versorgung von Patienten positiv beeinflussen.Currently German emergency departments are regularly affected by Overcrowding. A situation, in which the number of patients exceeds the available staff and resources. In this context the effective management of patient flow is therefore essential.
In order to improve the management of patient flow between inpatient and outpatient care the project OPTINOFA („Optimierung der Notfallversorgung durch strukturierte Ersteinschätzung mittels intelligenter Assistenzdienste“) developed an eponymous software tool for the intelligent initial assessment of patients in the emergency department. The tool not only provides a recommendation regarding treatment urgency but also suggests the most appropriate sector for patient care. This represents a novelty compared to established triage tools, such as the Emergency Severity Index (ESI).
In this thesis specific process and quality indicators, such as waiting time, overall length of stay in the emergency department, patient mortality and the concordance between the assessment of the two triage tools were analyzed. The evaluation was conducted monocentric in the emergency department of the Universitätsmedizin Göttingen. During the control period the patients were assessed using the established ESI tool, whereas in the intervention period both OPTINOFA and ESI assessments were performed to enable direct comparison between the individual triage levels.
While ESI showed a clear overrepresentation of patients in triage level 3, OPTINOFA distributed patients more evenly across the different triage levels. An analysis of the reasons for deviation between the recommendations of the two tools during the intervention period revealed that in 57,3% of all cases, adequate care was expected to be provided in a primary care center next to the emergency department.
The waiting time from triage assessment to the first physician contact was significantly reduced by 8 minutes during the intervention period. Comparison across the triage levels also revealed a significant decrease in waiting time for triage level 2 (6 min, p < 0,001), level 3 (12 min, p < 0,001) and level 4 (10 min, p < 0,001), whereas reductions in level 1 (4 min, p = 0,700 ) and level 5 (2 min, p = 0,596) were not statistically significant.
The overall time spend in the emergency room decreased by 8 minutes (p = 0,190) during the intervention period, however this result was not statistically significant. A significant decrease in overall stay was observed only among patients assessed with triage level 3 (9 min, p = 0,015).
Because of the limited number of events, no conclusion could be drawn regarding changes in mortality in the emergency department of the Universitätsmedizin Göttingen.
This monocentric study demonstrated that the use of OPTINOFA was associated with a reduction in waiting time but showed no significant change in overall length of stay. A significant reduction in length of stay could presumably not be demonstrated, as it is influenced to a greater extent than waiting time by external factors outside the emergency department, such as inpatient bed occupancy. The comparison of both tools during the intervention period suggests that a triage system like OPTINOFA, which also recommends outpatient treatment options outside the emergency department, effectively addresses the demand in emergency care given the current patient distribution. In summary, the implementation of OPTINOFA appears to be a promising approach for improving quality indicators in emergency departments and may therefore have a positive impact on patient care.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
In-ovo studies on the cellular metabolism of Hodgkin's lymphoma
No full textDie ausgezeichneten Überlebenschancen von Patienten mit Hodgkin-Lymphom (HL), einer bösartigen Neoplasie des lymphatischen Systems, können durch akute und langfristige Toxizitäten wie Infertilität, kardiovaskuläre Schäden oder sekundäre Malignome beeinträchtigt werden. Darüber hinaus werden dringend neue Therapien für Patient*innen benötigt, die nach einer Hochdosis-Chemotherapie einen Rückfall erleiden, mit dem Ziel, unerwünschte Risiken zu minimieren und gleichzeitig die Wirksamkeit zu erhalten. Zu den aufkommenden Therapieansätzen gehören kleine Moleküle, die intrazelluläre Proteine gezielt angreifen. Ein Beispiel dafür ist das Enzym Nicotinamidphosphoribosyltransferase (NAMPT), das in verschiedenen Tumorentitäten aberrant aktiv ist. In-vitro-Analysen haben gezeigt, dass chemische Inhibitoren der NAMPT toxisch für Zellen des HL sein können. Deshalb ist davon auszugehen, dass die NAMPT als geschwindigkeitsbestimmendes Enzym des Nicotinamidadenindinukleotid (NAD⁺)-Stoffwechsels wichtig für das HL ist. Es ist jedoch noch unklar, ob eine Intervention der NAMPT-Aktivität auch in vivo das Lymphomwachstum von HL-Zellen hemmt.
Ziel der vorliegenden Studie war es deshalb, ein präklinisches Xenograft-Modell zu nutzen. In dem In-ovo-Xenograft-Modell der Chorioallantoismembran des befruchteten Hühnereis (CAM) sollte untersucht werden, inwieweit die Inhibitoren FK866 und OT-82 die Lymphomentwicklung der L428-HL-Zellen verändern, sowie eine rot fluoreszierende, mCherry exprimierende Zelllinie für weiterführende In-ovo-Metabolismus-Analysen zu etablieren.
Es wurden Zellen der HL-Zelllinie L428 auf die CAM appliziert, die zuvor 24 Stunden mit FK866, OT-82 oder zur Kontrolle mit DMSO behandelt wurden. Die entstandenen Läsionen wurden nach 96 Stunden geerntet und histologisch sowie morphologisch charakterisiert. Zusätzlich zur Oberfläche wurde das Volumen der Tumore mittels Mikro-Computertomographie (micro-CT) bestimmt. Die mit FK866 und OT-82 behandelten Zellen waren noch in der Lage, in ovo Lymphome zu bilden, sie waren aber kleiner, weniger durchblutet und von geringerer Zelldichte bei höherem Kollagengehalt. Die Tumorzellen waren allerdings positiv für den Proliferationsmarker Ki67. Somit führt die Behandlung mit NAMPT-Inhibitoren zu einer Reduzierung von Tumorgröße und -durchblutung, nicht jedoch zu einem vollständigen therapeutischen Effekt.
Um zukünftige metabolische Analysen in ovo durchführen zu können, wurde eine Zelllinie etabliert, die das rot fluoreszierende Fusionsprotein mCherry-H2b exprimiert. Die hierbei etablierten Zelllinien reagierten in In-vitro- sowie in In-ovo-Studien ähnlich wie die parentale Zelllinie L428 auf die Behandlung mit den NAMPT-Inhibitoren FK866 und OT-82 hinsichtlich Zellviabilität, NAD+-Gehalt und NAMPT-Expression. Dies weist darauf hin, dass die etablierten Zelllinien für zukünftige Metabolismus-Analysen geeignet sind.
Zusammengefasst konnte ein Xenograft-Modell etablieren, das zur Analyse der NAMPT-Aktivität und deren Einfluss auf die Lymphomentwicklung geeignet ist. Weiterhin konnten wir zeigen, dass die NAMPT-Inhibition Einfluss auf die Lymphomentwicklung in ovo haben. Somit steht ein neues präklinisches Modell zur Untersuchung des Lymphommetabolismus, beispielsweise durch Fluoreszenzlebensdauer-Mikroskopie, zur Verfügung.Excellent survival rates of patients with Hodgkin lymphoma (HL), a malignant neoplasm of the lymphatic system, may be compromised by acute and long-term toxicities, including infertility, cardiovascular damage, and secondary malignancies. Furthermore, there is an urgent need for novel therapeutic strategies for patients who experience relapse following high-dose chemotherapy, with the aim of minimizing adverse effects while maintaining therapeutic efficacy. Upcoming treatment approaches include small molecules that selectively target intracellular proteins. One such target is the enzyme nicotinamide phosphoribosyltransferase (NAMPT), which has been found to be aberrantly active in various tumor entities. In vitro analyses have shown that chemical inhibition of NAMPT can be cytotoxic to HL cells. Consequently, as a rate-limiting enzyme in the nicotinamideadeninedinucleotide (NAD⁺) metabolism, NAMPT is presumed to play a crucial role in HL cells. However, it remains unclear whether inhibiting NAMPT activity can also suppress HL tumor growth in vivo.
The present study aimed to establish a preclinical xenograft model to investigate this question. Specifically, an in-ovo xenograft model of the chorio-allantoic membrane (CAM) of fertilized chicken eggs was employed to evaluate the effects of the NAMPT inhibitors FK866 and OT-82 on the development of L428 HL cells. This model has been shown to reflect key aspects of human lymphoma progression. Additionally, a red fluorescent mCherry-expressing cell line was established for future in-ovo metabolic analyses.
Cells of the L428 HL cell line were applied to the CAM following a 24-hour pre-treatment with FK866, OT-82, or dimethyl sulfoxide (DMSO) as a control. After 96 hours, the resulting lesions were harvested and characterized histologically and morphologically. In addition to tumor surface area, tumor volume was quantified using micro-computed tomography (micro-CT).
Although FK866- and OT-82-treated HL cells were still capable of forming tumors in ovo, the resulting lymphomas were smaller, less vascularized, and exhibited lower cellular density with an increased collagen content. However, tumor cells remained positive for the proliferation marker Ki67. Thus, NAMPT inhibition led to a reduction in tumor size and vascularization but did not achieve a complete therapeutic effect.
To facilitate future metabolic analyses in ovo, a cell line expressing the red fluorescent fusion protein mCherry-H2B was established. This newly generated cell line responded similarly to the parental L428 cell line in both in-vitro and in-ovo studies regarding cell viability, NAD⁺ levels, and NAMPT expression after treatment with FK866 and OT-82. This suggests that the established cell lines are suitable for future metabolism-focused investigations.
In summary, we successfully developed a xenograft model that enables the study of NAMPT activity and its impact on HL tumor development. Furthermore, we demonstrated that NAMPT inhibition influences lymphoma progression in ovo. This novel preclinical model provides a valuable tool for investigating lymphoma metabolism, including fluorescence lifetime microscopy-based analyses.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt. !Es liegt auch ein Embargo vor!These files are not accessible until the state exam has been completed
Analysis of the Risk of Progression from Monoclonal Gammopathy of Undetermined Significance to Multiple Myeloma Using Immunohistochemical Markers
No full textHintergrund: Die monoklonale Gammopathie unklarer Signifikanz (MGUS) gilt als präkanzeröse Vorstufe des Multiplen Myeloms mit einem jährlichen Progressionsrisiko von etwa 1–1,5 %. Das bislang etablierte Risikomodell der Mayo Clinic stützt sich vornehmlich auf klinische Parameter. Ziel der vorliegenden Untersuchung war die Identifizierung immunhistochemischer Risikofaktoren für die Progression.
Methoden: Retrospektiv wurden 608 Knochenmarkbiopsien von Patientinnen und Patienten mit MGUS analysiert. Unter Einsatz standardisierter Fixationsverfahren und monoklonaler Antikörper erfolgte der Nachweis verschiedener Differenzierungsmarker (CD138, CD56, CD20, Kappa- und Lambda-Leichtketten). Die Einteilung in drei Risikogruppen erfolgte anhand des Plasmazellanteils und des Vorliegens einer Leichtkettenrestriktion.
Ergebnisse: Eine immunhistochemisch nachweisbare Leichtkettenrestriktion (p = 0,00057) sowie eine CD56-Positivität der Plasmazellen (p = 0,00018) erwiesen sich als signifikante Risikofaktoren für eine Progression. Kein Einfluss zeigte sich hingegen für CD20, Alter, Geschlecht sowie den Quotienten der freien Leichtketten im Serum.
Schlussfolgerung: Die immunhistochemische Untersuchung von Knochenmarkbiopsien ermöglicht die Identifikation von Patientinnen und Patienten mit erhöhtem Progressionsrisiko und kann damit eine wertvolle Ergänzung zur klinischen Risikostratifizierung darstellen.Background: Monoclonal gammopathy of undetermined significance is a precancerous condition of MM with an annual risk of progression of 1-1.5%. The previously established risk stratification model of the Mayo Clinic is primarily based on clinical parameters. The aim of this study was to identify immunohistochemical risk factors for progression.
Methods: A retrospective analysis was performed on 608 bone marrow biopsies from patients with monoclonal gammopathy of undetermined significance. Standardised fixation methods and monoclonal antibodies were used to identify the different clusters of differentiation - CD138, CD56, CD20, kappa and lambda light chains. Patients were categorised into 3 risk groups based on the proportion of plasma cells and the presence of light chain restriction.
Results: Immunohistochemically detected light chain restriction (p = 0.00057) and CD56 positivity of plasma cells (p = 0.00018) were identified as significant risk factors for progression. CD20, age, gender and the level of the free light chain quotient in the serum had no influence on the probability of progression.
Conclusion: Immunohistochemical analysis of bone marrow helps to identify patients with a high risk of progression.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Psychische Belastung bei älteren multimorbiden Menschen mit Herzinsuffizienz: Zwei-Monats-Verlauf und dessen Vorhersage
No full textDue to the increasingly aging population, the number of people suffering from heart failure and multimorbidity is rising. Factors such as age, heart failure, and multimorbidity have a negative impact on psychological symptoms such as anxiety and depression, which were assessed in this study using the Hospital Anxiety and Depression Scale as psychological distress or psychological stress. Psychological stress was examined over a spontaneous period of two months in older, multimorbid patients with heart failure. In addition, psychosocial predictors of high psychological distress in these patients were investigated. Methodologically, t-tests were primarily used to test differences in means, Pearson and Spearman correlation analyses were performed, and multiple linear regression was conducted. In summary, this study showed that the HADS at time T0 and the number of pre existing conditions were the strongest predictors of psychological distress two months later. After classifying this study within the current state of research, further variables should nevertheless be investigated as possible predictors of persistent psychological distress in older, multimorbid people with heart failure due to the limitations of this study.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Pankreatisch zystische Neoplasien und das orointestinale Mikrobiom: Evaluierung als Biomarker
No full textPancreatic cystic neoplasms (PCN) are mostly benign cystic lesions of the pancreas, which can be a precursor lesion for pancreatic cancer. The risk of malignancy varies widely, depending on the entity of the PCN. Despite known risk factors and several studies, it has not yet been possible to reliably predict which patients with PCN will develop worrisome features or high-grade dysplasia and will therefore benefit from an early operation. Currently, it was revealed the benign pancreatic cysts and the pancreatic cancer harbors an own microbiome, Furthermore, the orointestinal microbiome can be exploited as a predictor for a pancreatic mass dignity. However, there is still a lack of knowledge whether the microbiome can predict the course of PCN. The aim of this prospective study was to investigate the orointestinal microbiome of patients with PCN and the association with the cyst entities, the Dutch-American risk stratification tool (DART-1) score and the presence of worrisome features in branch-duct intraductal papillary mucinous neoplasm (BD-IPMN).
Buccal and rectal swab samples were prospectively collected to analyze the microbiome of patients with PCN. The microbiome was assessed by Oxford Nanopore sequencing technology (16S rRNA and metagenomics). Clinical data was collected with a standardized online questionnaire (RedCap). 78 patients have been enrolled in the study between January 2021 and December 2022. Alpha diversity metrics as the Observed Species, Shannon Index and Inverse-Simpson Index were determined and compared between the patients. Furthermore, the relative difference between these groups was shown and calculated using beta diversity distance metrics.
The buccal microbiome of patients with BD-IPMN with worrisome features, as defined by the Fukuoka guidelines of 2017, revealed to harbor significantly different species compared to those without worrisome features. The rectal microbiome showed no significant differences between the two groups. In addition, a higher DART-1 score in patients with BD-IPMN was associated with significantly lower alpha diversity. No significant differences in the buccal or rectal microbiome were found between the cyst entities.
The present study provides an opportunity to further research the microbiome as a biomarker for the progression of PCN.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Reevaluation der standardisierten CCT - Kontrollbildgebung bei Kindern nach neurochirurgischer Tumorresektion
No full textNach operativen Eingriffen im Bereich der Neurochirurgie wurde standardmäßig eine postoperative kraniale Bildgebung mittels Computertomographie (CCT) als angewandtes Kontrollverfahren herangezogen. Ziel war es, eine durch die Operation entstandene und therapeutisch relevante Komplikation zu detektieren oder auszuschließen. Jedoch birgt die routinemäßige Nutzung dieser postoperativen Bildgebung einige Nachteile, wie die Risiken durch die Strahlenbelastung, den intrahospitalen Transport und die entstehenden Kosten. Kinder gelten als besonders vulnerabel hinsichtlich diagnostischer Strahlenbelastung, und es besteht ein erwiesenermaßen signifikant höheres Risiko der Entstehung einer Neoplasie. Es galt, erstmalig zu evaluieren, inwieweit das frühpostoperative Kontroll-CCT, auch EPOCT genannt (early postoperative computed tomography), nach speziell pädiatrisch neurochirurgischer Tumorresektion für die postoperative Überwachung und Behandlung einen relevanten therapeutischen Nutzen hat. Innerhalb dieser retrospektiven klinischen Studie wurden Daten aller pädiatrischen Patienten des Schwerpunktes Kinderneurochirurgie der UMG untersucht, die sich zwischen 2011 und 08/2022 einer intrakraniellen Tumorresektion sowie innerhalb von vier Stunden einer EPOCT unterzogen haben. Es wurden selektierte Variablen gesammelt und hinsichtlich ihrer Assoziation mit dem Outcome der EPOCT einzeln untersucht. Im Anschluss wurden acht logistische Regressionsanalysen und ROC-Kurven erstellt, um mehrere Variablen gleichzeitig im gemeinsamen Einfluss auf das Ergebnis der Kontrollbildgebung darzustellen und eine Schätzung des Outcomes zu ermöglichen. Es erwiesen sich bestimmte Variablen als signifikant in der Assoziation mit einer auffälligen EPOCT: Die neurologischen Defizite unmittelbar postoperativ, die präoperativen Maße der Ventrikelweite ER und FOHR, eine präoperativ gelegte extraventrikuläre Drainage EVD, die OP-Dauer und eine intra- oder unmittelbar postoperative Erythrozytentransfusion. Im Rahmen der logistischen Regressionsanalysen konnten zur Schätzung des Outcomes der EPOCT drei der acht Modelle mit der höchsten Güte herausgestellt werden: Neurologische Defizite in Modell 1 mit EVD (AUC 0,82), in Modell 3 mit Tumorlokalisation (AUC 0,81) und in Modell 4 mit OP-Dauer (AUC 0,85). Es ließ sich jeweils ein Score erstellen, der eine Indikationsstellung für eine EPOCT erlaubt. Es zeigte sich, dass die neurologische Auffälligkeit einen starken Zusammenhang mit dem Ergebnis der EPOCT aufweist. In Anbetracht einer möglichen Indikation zur notfallmäßigen Rückkehr in den Operationssaal konnte gezeigt werden, dass die neurologische Untersuchung einen höheren Stellenwert einnahm als die EPOCT. In keinem einzigen Fall wurde eine notfallmäßige Reoperation allein durch eine auffällige Bildgebung indiziert. Zusammenfassend lässt sich festhalten, dass die routinemäßige EPOCT zur Indikationsstellung einer notfallmäßigen Reoperation nach neurochirurgischer Tumorresektion der klassischen neurologischen Untersuchung nicht überlegen ist. Es konnten Risikofaktoren identifiziert werden, die nachweislich signifikant mit einer auffälligen Kontrollbildgebung oder einer Veränderung im Patientenmanagement einhergingen. Zudem konnten Scores erstellt werden, die eine Einschätzung des Outcomes der EPOCT in kausalem Zusammenhang mit zwei Variablen ermöglichen. Nach aktuellem Stand ist es noch nicht möglich, einen exakten Score zu erstellen, der fallübergreifend als Wegweiser dienen kann. Bis dies gelingt, möglichst mittels einer größeren, prospektiven Studie, gilt es, die EPOCT von ihrer Position als routinemäßige Kontrolle abzulösen und sie lediglich als unterstützendes Hilfsmittel heranzuziehen.After surgical interventions in the field of neurosurgery, postoperative cranial imaging using computed tomography (CCT) was used as a standard control procedure. The aim was to detect or rule out any therapeutically relevant complications resulting from the operation. However, the routine use of this postoperative imaging has a number of disadvantages, such as the risks associated with radiation exposure, intrahospital transportation and the costs incurred. Children are considered to be particularly vulnerable to diagnostic radiation exposure, and there is a proven significantly higher risk of neoplasia developing. The aim was to evaluate for the first time the extent to which early postoperative computed tomography (EPOCT) has a relevant therapeutic benefit for postoperative monitoring and treatment after tumor resection specifically in pediatric neurosurgery. Within this retrospective clinical study, data of all pediatric patients of the department of pediatric neurosurgery of the UMG who underwent intracranial tumor resection and an EPOCT within four hours between 2011 and 08/2022 were examined. Selected variables were collected and individually inspected with regard to their association with the outcome of the EPOCT. Subsequently, eight logistic regression analyses and ROC curves were created to show the joint influence of several variables on the result of the control imaging and to enable an estimation of the outcome. Certain variables were found to be significantly associated with an abnormal outcome of the EPOCT: immediate postoperative neurologic deficits, preoperative measures of ventricular width ER and FOHR, a preoperatively placed extraventricular drain EVD, duration of surgery, and an intraoperative or immediate postoperative erythrocyte transfusion. Within the logistic regression analyses, three of the eight models with the highest quality were identified for estimating the outcome of the EPOCT: Neurological deficits in model 1 with EVD (AUC 0.82), in model 3 with tumor localisation (AUC 0.81) and in model 4 with duration of surgery (AUC 0.85). In each case, a score was generated that allowed an indication for the EPOCT to be determined. It was shown that neurological deficits had a strong correlation with the result of the EPOCT. In view of a possible indication for an emergency return to the operating room, it was shown that the neurological examination was a better predictor than the EPOCT. In no single case was an emergency reoperation indicated by abnormal imaging alone. In summary, it can be concluded that routine EPOCT is not superior to conventional neurological examination for the indication of emergency reoperation after neurosurgical tumor resection. Risk factors were identified that were proven to be significantly associated with abnormal control imaging or a change in patient management. In addition, scores were created that enable an assessment of the outcome of the EPOCT in causal relation with two variables. As things stand, it is not yet possible to create an exact score that can serve as a guide across all cases. Until this is achieved, ideally through a larger, prospective study, the EPOCT must be removed from its position as a routine control and used merely as a supportive tool.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Establishment and characterization of cervical carcinoma cell lines with stable overexpression of the G-protein-coupled estrogen receptor (GPER1)
No full textCervical cancer (CC) remains the fourth most common malignancy among women worldwide, despite effective HPV vaccination strategies. CC can be classified into different histological subtypes. The majority of cases are cervical squamous cell carcinomas (CSCC), followed by adenocarcinomas (CAC), the latter including a higher proportion of HPV-negative tumors. These subtypes differ in their etiology, pathology, and clinical presentation. While the incidence of CSCC has been declining, CAC incidence has increased in recent years.
GPER1 is a membrane-bound G protein-coupled receptor with seven transmembrane domains that activates various intracellular signaling cascades. These include cAMP production, the Rho-ROCK pathway, and EGFR transactivation, which subsequently stimulate MAPK and Akt pathways. Through HIF-1α, GPER1 further modulates NOTCH and VEGF signaling. GPER1 plays a relevant role in the initiation and progression of several malignancies, including CC.
To elucidate the specific role of GPER1 in CC, stable overexpression (OE) of GPER1 was established in the CC cell lines SiHa and HeLa using a non-viral Sleeping-Beauty transposon-based vector. Stable GPER1-OE was confirmed by RT-qPCR, Western blotting, and flow cytometry (FACS). Functional consequences of GPER1-OE were assessed by examining tumor-associated cellular behaviors including proliferation, migration, invasion, apoptosis, metabolic viability, as well as stem-cell-associated properties via colony- and tumorsphere-formation assays. In addition, next-generation sequencing (NGS) was conducted to identify differential gene expression and signaling pathways particularly relevant for tumor development and progression.
Overall, GPER1-OE resulted in a more aggressive phenotype in SiHa cells (CSCC), characterized by increased proliferation, migration, and enhanced cancer stem-cell-like traits. In contrast, HeLa cells (CAC) displayed a less aggressive phenotype, with reduced proliferation and migration, increased apoptosis, and diminished stem-cell properties. The NGS analysis supported these findings, revealing an upregulation of mTOR, MYC, p53, EMT, and angiogenesis-related pathways in SiHa cells with GPER1-OE, whereas these pathways were predominantly downregulated in HeLa cells, accompanied by suppressed Hedgehog, KRAS, and Wnt/β-catenin signaling. These results suggest that GPER1 can exert either tumor-promoting or tumor-suppressive effects in CC depending on the histological subtype.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Identification and characterisation of type II neuroblasts in the embryo of the red flour beetle Tribolium castaneum
No full textJacob-Henle-Programm der Universitätsmedizin GöttingenEvolution has created a wide range of morphological diversity in insect brains, while the basic structure is conserved. Little is known about the mechanisms that lead to this evolutionary diversification of similar structures. The central complex, one of these neuropiles, shows evolutionary heterochrony: While the hemimetabolious grasshopper Schistocerca gregaria builds up this whole structure during the embryonic period, the highly derived holometabolous fruit fly Drosophila melanogaster develops it mainly in the late larval and pupal stages. Neurogenesis in insects is carried out by neuroblasts. Most of the insect nervous system is build up by type I neuroblasts but for central complex development in Drosophila and Schistocerca also type II neuroblasts have been discovered. Those have the ability to produce more progeny by generating intermediate progenitor cells. Regarding to the central complex development, the red flour beetle Tribolium castaneum shows an intermediate position by building up an immature but already functional version of this neuropil in the late embryo. Using mRNA in situ hybridisation and antibody staining on transgenic lines that mark distinct genes, this work identified actively proliferating cell lines produced by type II neuroblasts in the Tribolium embryo that take part in the embryonic central complex genesis. A high degree of conservation could be shown, especially regarding their dorsomedial position in the embryonic head and their characteristic gene expression pattern, which appears homologous to the situation in Drosophila. However, the unexpected finding that Tribolium generates nine type II neuroblasts, while only eight could be found in Drosophila and Schistocerca, combined with the fact that Tribolium embryonic type II lines could be characterised as containing significantly more cells than those in Drosophila leads to the conclusion that embryonic type II neuroblasts seem to be a factor for the relatively earlier central complex development in Tribolium. Regarding this, type II neuroblasts appear also as an interesting model for further studies on heterochrony during insect brain development.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Identification of differentially m6A methylated circRNAs in patient derived RBM20 mutated and control iPS-Cardiomyocytes
No full textApproximately 5% of dilated cardiomyopathies are caused by a mutation in the RBM20 gene, which encodes a protein involved in the splicing of cardiac specific titin and formation of cTTNs, the titin specific circRNA. Although circular RNAs (circRNAs) belong to the class of non-coding RNAs, recent findings suggest that they can indeed be translated independently of their 3′ and 5′ ends. The functions of proteins encoded by circRNAs remain largely unknown. Among various epigenetic modifications, N6-methyladenosine (m6A methylation) is the most prevalent in both DNA and RNA, and has been shown to enhance the translation efficiency of circRNAs.
Each of these elements, RBM20 mutations, circRNA biogenesis, and m6A methylation, has been individually implicated in the development of heart failure. However, no studies to date have examined their interactions and potentially combined impact on cardiac dysfunction.
In this study, we isolated and characterized m6A-methylated circRNAs from induced pluripotent stem cell (iPSC)-derived cardiomyocytes from RBM20 mutated patients and healthy controls, using MeRIP (methylated RNA immunoprecipitation) and subsequent next-generation sequencing. We also analyzed the expression of enzymes responsible for m6A methylation at both gene and protein levels using qPCR and Western blotting.
Our results revealed a higher abundance of m6A-methylated circRNAs in RBM20 mutated cardiomyocytes compared to controls. Additionally, the m6A modification sites within circRNAs differed significantly between the two groups. The general transcriptional activity appeared elevated in RBM20 mutated cells. Furthermore, we identified PTPRZ1, PAK3, and NTRK2 as the most prevalent m6A-modified circRNAs unique to RBM20 mutated cells. Interestingly, the expression of m6A methylation-related enzymes on gene level was significantly higher in control cells, while the expression on protein level was significantly elevated in the RBM20 mutated cells.
This study is the first to investigate the interplay between RBM20 mutations and m6A methylation in circRNAs, providing novel insights into their potential role in the pathogenesis of heart failure.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt.These files are not accessible until the state exam has been completed
Bacteriorhodopsin-like cation channelrhodopsin based optogenetic tools for the future optical cochlear implant
No full textElse-Kröner-Fresenius-Promotionskolleg für Medizinstudierende GöttingenDeafness is a widespread and severe condition. Electrical cochlear implants, which use electrical stimulation of the auditory nerve, enable speech comprehension in those patients suffering from sensorineural hearing loss. However, the frequency resolution of these implants is limited due to the broad spread of electrical current. To address this issue, the use of light, which can be more precisely confined in space, is being developed as the basis for an optical cochlear implant. The introduction of light-gated ion channels, known as channelrhodopsins, into spiral ganglion neurons enables the necessary light-driven excitation. However, channelrhodopsins exhibit significant variation in their electrophysiological properties. None of the published variants meets all the criteria for use in an optical cochlear implant. This doctoral thesis primarily focuses on the criteria redshifted action spectrum, fast channel kinetics, large current densities, and minimal desensitization.
This doctoral thesis aims to expand the optogenetic toolbox and contribute to designing a channelrhodopsin variant suitable for optical cochlear implants. This aim was pursued through three different approaches: investigating representatives of the newly described Bacteriorhodopsin-like channelrhodopsin family, improving the characteristics of the published variant ChRmine, and contributing to the establishment of automation for channelrhodopsin characterization. NG cells were used to express channelrhodopsin variants, which were then characterized through whole-cell patch-clamp experiments. Plasma membrane expression was assessed by analyzing line profiles from single-stack confocal images. The effectiveness of the automated patch clamp system SyncroPatch 384 in determining light dependence was investigated by comparing it to the manual patching set-up.
The investigation of Bacteriorhodopsin-like channelrhodopsins revealed a significant variability within the subfamily. One representative, DN22769-c0-g2-i1, demonstrated fast channel kinetics and reduced desensitization, making it a valuable candidate for in vivo applications. Attempts to increase the current density of this variant by optimizing plasma membrane expression were unsuccessful. However, a more detailed examination of plasma membrane expression uncovered additional variability within the Bacteriorhodopsin-like channelrhodopsin subfamily. The investigation of various ChRmine variants revealed that mutations within a random coil region between transmembrane helix two and three affect closing kinetics. Further investigation of this region could result in the development of a ChRmine variant with faster closing kinetics. Two variants, ChReef-H33R and ChReef-T119A, demonstrated accelerated closing kinetics while maintaining current densities similar to wild-type values. Combining both mutations in the variant ChReef-H33R/T119A did not potentiate the accelerating effects on closing kinetics.
This thesis deepens the understanding of the mechanisms behind ChRmines’ photocycle by characterizing its variants. Furthermore, it demonstrates the reproducibility of a light dependence measurement obtained manually using the automated patch clamp system SyncroPatch 384. Additional work is required to establish this system, but the results suggest the potential for future automation in characterizing channelrhodopsins. This could significantly accelerate the investigation of new variants and the optimization of known ones. Based on these results, it is recommended to utilize automated patch-clamp to examine numerous variants of Bacteriorhodopsin-like channelrhodopsin and ChRmine. These variants can be obtained from mutant libraries based on partially advantageous variants, such as ChReef-H33R, and hot spot regions, such as the random coil region between transmembrane helix two and three.10000-01-01Diese Dateien sind bis zum Abschluß der Staatsexamensprüfung gesperrt. !Es liegt auch ein Embargo vor!These files are not accessible until the state exam has been completed.These files are not accessible until the state exam has been completed