Erniedrigter Anteil der CD4+/CD8+ Lymphozyten im Blut bei Morbus Alzheimer

Hintergrund und Ziele: Die Alzheimer Erkrankung (AE) gehört zu den häufigsten Erkrankungen des Alters und stellt aufgrund des demographischen Wandels zunehmende Herausforderungen für die Gesellschaft dar. Die Diagnosestellung findet meist erst im fortgeschrittenen Krankheitsverlauf mittels Liquorpunktion statt. Bisher ist die Krankheitsursache nicht vollständig geklärt und eine kurative Therapie derzeit nicht möglich. In dieser Arbeit werden verschiedene Oberflächenmoleküle auf Monozyten und Lymphozyten in Liquor und Blut untersucht, um Zusammenhänge zwischen der AE und einer veränderten Immunantwort auf Entzündungsprozesse genauer zu untersuchen. Ziel ist es, Biomarker zu identifizieren, die sich für eine Diagnosestellung mittels Bluttest eignen könnten, auch um die invasivere Liquorpunktion zu vermeiden. Methoden: Patienten der Gedächtnissprechstunde in der Psychiatrischen und Psychotherapeutischen Klinik Erlangen wurden Liquor- und Blutproben entnommen. Aus den Proben wurden Monozyten und Lymphozyten mit den fluoreszierenden Antikörpern CD14, CD16, CD4, CD8, MSR1, CCR5 und CCR7 markiert und anschließend mittels Durchflusszytometrie analysiert. Die so gewonnenen Daten wurden auf Unterschiede zwischen Patienten mit AE im Vergleich zu Patienten ohne AE untersucht. Beobachtungen und Ergebnisse: Die Liquor- und Blutanalysen wurden bei 55 Patienten durchgeführt (35 Männer, 20 Frauen; medianes Alter: 63,13 Jahre). Davon wurden 23 der Gruppe AE (15 Männer, 8 Frauen) und 32 der Kontrollgruppe (20 Männer, 12 Frauen) zugeordnet. Der Anteil der CD4+/CD8+ Lymphozyten an allen Lymphozyten im Blutwar bei AE signifikant erniedrigt im Vergleich zur Kontrollgruppe (p-Wert: 0,013). Im Liquor wurde hierbei das Signifikanzniveau nicht erreicht (p-Wert: 0,051). Bei den drei Subpopulationen klassische, intermediäre und nicht klassische Monozyten, bei den Oberflächenmolekülen CCR5 und CCR7 auf Monozyten und Lymphozyten, sowie bei MSR1 auf den CD16-negativen Monozyten konnten weder im Blut noch im Liquor signifikante Unterschiede zwischen den beiden Gruppen festgestellt werden. Schlussfolgerung: Der im Rahmen dieser Arbeit identifizierte erniedrigte Anteil der CD4+/CD8+ Lymphozyten im Blut bei Patienten mit AE könnte sich künftig in Kombination mit anderen Markern als potenzieller Biomarker für die Diagnosestellung der AE mittels eines Bluttests eignen. Weitere prospektive Studien sind notwendig, um diese Effekte zu explorieren.Background and Objectivs: Alzheimer’s disease (AE) is one of the most common diseases of old age and poses increasing challenges to society due to demographic change. Diagnosis usually occurs only in the advanced course of the disease by means of cerebrospinal fluid (CSF) puncture. So far, the cause of the disease is not fully understood and curative therapy is currently not possible. In this work, various surface molecules on monocytes and lymphocytes in CSF and blood are examined in order to investigate correlations between AE and an altered immune response to inflammatory processes in more detail. The aim is to identify biomarkers that might be suitable for diagnosis using a blood test, and also to avoid the more invasive CSF puncture. Design and Methods: CSF and blood samples were taken from patients of the memory consultation at the Department of Psychiatry and Psychotherapy of the University Hospital Erlangen. Monocytes and lymphocytes from the samples were labeled with the fluorescent antibodies CD14, CD16, CD4, CD8, MSR1, CCR5, and CCR7 and subsequently analyzed by flow cytometry. The resulting data were analyzed for differences between patients with AE compared to patients without AE. Observations and Results: CSF and blood analyses were performed in 55 patients (35 men, 20 women; median age: 63.13 years). Of these, 23 were assigned to the AE group (15 men, 8 women) and 32 to the control group (20 men, 12 women). The percentage of CD4+/CD8+ lymphocytes in all lymphocytes in the blood was significantly decreased in AE compared to the control group (p-value: 0.013), whereas in CSF no statistically significant differences could be observed (p-value: 0.051). Furthermore, no significant differences could be shown between patients with AE and the control group in the surface molecules CCR5 and CCR7 on monocytes and lymphocytes, in MSR1 on CD16-negative monocytes, as well as in the three subpopulations classical, intermediate and non-classica monocytes, neither in blood nor in CSF. Conclusion: The decreased percentage of CD4+/CD8+ lymphocytes in the blood of patients with AE detected in this work holds potential for a future biomarker for the diagnosis of AE by a blood test in addition to other markers. Further prospective studies are needed to explore these effects

Protein folding on the ribosome studied using NMR spectroscopy

NMR spectroscopy is a powerful tool for the investigation of protein folding and misfolding, providing a characterization of molecular structure, dynamics and exchange processes, across a very wide range of timescales and with near atomic resolution. In recent years NMR methods have also been developed to study protein folding as it might occur within the cell, in a de novo manner, by observing the folding of nascent polypeptides in the process of emerging from the ribosome during synthesis. Despite the 2.3 MDa molecular weight of the bacterial 70S ribosome, many nascent polypeptides, and some ribosomal proteins, have sufficient local flexibility that sharp resonances may be observed in solution-state NMR spectra. In providing information on dynamic regions of the structure, NMR spectroscopy is therefore highly complementary to alternative methods such as X-ray crystallography and cryo-electron microscopy, which have successfully characterized the rigid core of the ribosome particle. However, the low working concentrations and limited sample stability associated with ribosome-nascent chain complexes means that such studies still present significant technical challenges to the NMR spectroscopist. This review will discuss the progress that has been made in this area, surveying all NMR studies that have been published to date, and with a particular focus on strategies for improving experimental sensitivity

Biosynthesis of Salmonella enterica [NiFe]-hydrogenase-5 : probing the roles of system-specific accessory proteins

A subset of bacterial [NiFe]-hydrogenases have been shown to be capable of activating dihydrogen-catalysis under aerobic conditions; however, it remains relatively unclear how the assembly and activation of these enzymes is carried out in the presence of air. Acquiring this knowledge is important if a generic method for achieving production of O2-resistant [NiFe]-hydrogenases within heterologous hosts is to be developed. Salmonella enterica serovar Typhimurium synthesizes the [NiFe]-hydrogenase-5 (Hyd-5) enzyme under aerobic conditions. As well as structural genes, the Hyd-5 operon also contains several accessory genes that are predicted to be involved in different stages of biosynthesis of the enzyme. In this work, deletions in the hydF, hydG, and hydH genes have been constructed. The hydF gene encodes a protein related to Ralstonia eutropha HoxO, which is known to interact with the small subunit of a [NiFe]-hydrogenase. HydG is predicted to be a fusion of the R. eutropha HoxQ and HoxR proteins, both of which have been implicated in the biosynthesis of an O2-tolerant hydrogenase, and HydH is a homologue of R. eutropha HoxV, which is a scaffold for [NiFe] cofactor assembly. It is shown here that HydG and HydH play essential roles in Hyd-5 biosynthesis. Hyd-5 can be isolated and characterized from a ΔhydF strain, indicating that HydF may not play the same vital role as the orthologous HoxO. This study, therefore, emphasises differences that can be observed when comparing the function of hydrogenase maturases in different biological systems

Serum Prolaktin-Konzentrationen als Risikofaktor des Metabolischen Syndroms oder Typ 2 Diabetes Mellitus?

Das Ziel dieser Arbeit ist es auf Basis einer großen populationsbasierten Kohorte im Rahmen der SHIP-Studie (Study of Health of Pommerania) die mögliche Assoziation zwischen der Serum PRL-Konzentration mit dem MetS und dem T2DM aufzuzeigen. Dieser Sachverhalt wurde bereits in früheren ausgewählten Studien mit kleineren Kohorten untersucht. In unserer Studie wurden dazu die Daten von 3,993 Individuen (2,027 Frauen) in einem Alter von 20-79 Jahren aus der populationsbasierten SHIP-Studie verwendet. Die Assoziation zwischen PRL-Konzentrationen und MetS sowie dem T2DM wurden sowohl im Queer- als auch im Längsschnitt mittels alters- und multivariabel-adjustierten Poisson-Regressionsmodellen untersucht. PRL wurde log-transformiert und als kontinuierliche (per Anstieg der Standartabweichung (SD)) oder kategoriale (geschlechtsspezifische Quartil) Einflussvariable, getrennt nach Männern und Frauen, dargestellt. Die Querschnittsanalyse zeigte eine inverse Assoziation zwischen niedrigen PRL Konzentrationen und einem prävalenten T2DM Risiko sowohl in Männern als auch in Frauen nach multivariabler Adjustierung (Männer: Q1 vs. Q4: relatives Risiko (RR), 1,55; 95% Konfidenzintervall (CI), 1.13 – 2.14; Frauen: Q1 vs. Q4: RR, 1.70; 95% CI, 1.10 – 2.62). Gleichermaßen wurde höhere PRL Konzentrationen mit signifikant niedrigerem T2DM Risiko assoziiert (RR pro SD Anstieg in log-transformierten PRL: 0,83, 95% CI, 0,72-0,95 bei Männern und 0,84, 95% CI, 0,71 bis 0,98 bei Frauen). Die inverse Assoziation zwischen PRL und dem MetS konnte nach der multivariablen Adjustierung nicht beibehalten werden. In der Längsschnittanalyse konnte die Assoziation zwischen PRL und inzidentem MetS oder T2DM nicht aufrechterhalten werden. Zusammenfassend ist dies die erste große populationsbasierte Studie, welche im Querschnitt über eine inverse Assoziation zwischen PRL und prävalentem T2DM in beiden Geschlechtern berichten kann. Jedoch deutet die fehlende longitudinale Assoziation darauf hin, dass PRL keine kausale Rolle als Risikofaktor für einen inzidenten T2DM oder MetS darstellt.Objective: To investigate potential associationsof serum prolactin concentration (PRL)withmetabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM), previously observed in small and selected study samples, in a large population-based cohort. Methods: Data from 3,993 individuals (2,027 women) aged 20-79 years from the population-based Study of Health of Pomerania (SHIP) were used to analyse cross-sectional and longitudinal associations ofPRL with MetS and T2DM risk in age- and multivariable-adjusted Poisson regression models. PRL were log-transformed andmodelled as continuous (per standard deviation (SD) increase) and categorical predictor (sex-specific quartiles) variable, separately for men and woman. Results: Cross-sectional analyses showed an inverse association between low PRL concentrations and prevalent T2DM risk in men and women after multivariable-adjustment (men: Q1 vs. Q4: relative risk (RR), 1.55; 95% confidence interval (CI), 1.13 – 2.14; women: Q1 vs. Q4: RR, 1.70; 95% CI, 1.10 – 2.62). Likewise, higher PRL concentrations were associated with significantly lower T2DM risk (RR per SD increase in log-PRL: 0.83; 95% CI, 0.72 – 0.95 in men, and 0.84; 95% CI, 0.71 – 0.98 in women, respectively).An inverse association between PRL and MetS risk was not retained after multivariable adjustment. Longitudinal analyses yielded no association of PRL with incident MetS or T2DM. Conclusion: The present study is the first large population-based study reporting a cross-sectional inverse association between PRL and prevalent T2DM in both genders. But the absent longitudinal associations do not support a causal role of PRL as a risk factor of incident MetS or T2DM

RheumMadness Over Two Years: Engaging Participants in Active Learning and Connecting Early Trainees to the Rheumatology Community

Objective RheumMadness is an online learning collaborative that seeks to actively engage the rheumatology community. The objective of this manuscript is to analyze the educational experience of RheumMadness over two years. Methods Direct measures of participant engagement were obtained using web‐based analytics. An electronic survey was created after the tournament to capture self‐reported engagement and educational experience using the Community of Inquiry framework. Data were analyzed according to the following objectives: (1) compare demographics, engagement, and educational experience of participants between 2021 and 2022; (2) describe the educational experience of those who created scouting reports; (3) explore the impact of RheumMadness on early learners (medical students and residents). Results Compared with 2021, the 2022 tournament had more participants who submitted a bracket, more early learners, and more scouting report creators. Self‐reported engagement and educational experience was high in both years of the tournament among all participants. Over 85% of scouting report creators reported that making a report was a fun and valuable learning experience. Early learners reported significantly higher levels of knowledge integration, sense of belonging in the rheumatology community, social connection, and overall learning experience compared with more advanced participants. Eighty‐five percent of early learners reported that RheumMadness increased their interest in rheumatology. Conclusion RheumMadness expanded from 2021 to 2022, engaging more participants in collaborative learning. Our results demonstrate that RheumMadness is particularly impactful among medical students and residents by helping them explore rheumatology topics and connect with the rheumatology community