1,721,011 research outputs found
GESTATIONAL DIABETES MELLITUS INTERFERESWITH THE BIOLOGICAL CHARACTERISTICS OFWHARTON'S JELLY MESENCHYMAL STEM CELLS.
No full textRecent research indicates that the origin of obesity and related
metabolic disorders is not only caused by genetic and risk
factors in adult life (unbalanced diet, insufficient physical
activity) but also may be influenced by the perinatal environment.
In addition, studies in animal models suggest that the
mesenchymal stem cell commitment into pre-adipocytes can
already occur during fetal development and perinatal life.
Since the number of pre-adipocytes and mature adipocytes is
lower in normal subjects than in obese subjects, changes in the
prenatal maturational process may play a role in the pathogenesis
of obesity and metabolic-associated diseases.
Gestational diabetes mellitus is related to an increased risk of
obesity, early onset of metabolic syndrome and type 2 diabetes
in the offspring. For this reason it would be useful to investigate
how the perinatal environment may affect fetal mesenchymal
stem cells, especially in deregulated gestational diabetes,
where the fetal environment is modified in terms of hormone
levels and nutrition. Therefore, we have compared
Wharton’s jelly mesenchymal stem cells (WJ-MSC) obtained
from umbilical cord of both healthy and diabetic mothers, in
order to better understand the mechanisms involved in metabolic
diseases in offspring of diabetic mothers. Results indicate
that WJ-MSC from diabetic mothers display, in contrast to
cells from healthy mothers, a higher ability to differentiate
towards the adipogenic lineage. This suggests that the diabetic
uterine environment may be responsible for a “pre-commitment”
that could give rise in the post natal life to an alteration
of adipocyte production upon an incorrect diet style, which in
turn would produce obesity
Analysis of CMV-specific T cell responses and CMV-associated changes in the ageing human immune system
No full textDie Veraenderungen des Immunsystems mit zunehmendem Alter, Immunseneszenz genannt, resultieren in erhoehter Infektanfaelligkeit. Infolge dessen leiden aeltere Menschen unter haeufigeren und schwerer verlaufenden Infekten, Autoimmunerkrankungen und vermindertem Impfschutz. Immunseneszenz entsteht nicht nur aufgrund chronologischen Alterns, sondern wird auch durch andere teils ungeklaerte Faktoren verursacht. Cytomegalievirus (CMV) ist ein Herpesvirus, dass in immunkompetenten Menschen lebenslang persistiert. Infolge chronischer Immunaktivierung traegt CMV zur beschleunigten Immunseneszenz bei. In dieser Arbeit wurden die Alters- und CMV-induzierten Veraenderungen in humanen T-Zellen analysiert. Dafuer wurden PBMC von 50 gesunden Spendern in drei verschiedenen Altersgruppen antigenspezifisch (CMV-Proteine pp65 und IE1 und protein purified derivate von Mycobacterium tuberculosis (PPD)) und polyklonal (OKT3) in vitro stimuliert. Ein 11-Farben-Panel wurde etabliert, um die simultane Expression der Differenzierungsmarker CD45RA und CD27 und der Aktivierungsmarker CD40L, IFNg, IL2 und TNF auf T-Zellen durchflusszytometrisch zu untersuchen. Die Ergebnisse dieser Arbeit zeigten, dass die antigenabhaengige Differenzierung der Gedaechtnis-T-Zellen mit zunehmendem Alter und CMV-Infektion zunahm. Die Differenzierung der Gedaechtnis-T-Zellen in CMV-positiven Spendern war ausserdem mit der Antwortgroesse gegen pp65 korreliert. Die pp65-spezifische, aber nicht die IE1-spezifische polyfunktionale T-Zell-Antwort nahm mit zunehmendem Alter der Probanden zu. Zusammenfassend kann gesagt werden, dass CMV einen grossen Einfluss auf das Immunsystem gesunder Individuen hat. Die Differenzierung der Gedaechtnis-T-Zellen ist nicht nur abhaengig von der Infektion mit CMV, sondern auch davon, wie das Immunsytem auf CMV reagiert. Polyfunktionale CMV-spezifische T-Zellen, die wahrscheinlich CMV kontrollieren, sind vorhanden und werden nicht von dysfunktionalen T-Zellen im Alter verdraengt.Ageing of the immune system, also called immunosenescence, is a phenomenon that leads to increased susceptibility to infections in elderly people. Persistent cytomegalovirus (CMV) infection induces strong T cell responses in humans and is thought to be one of the driving forces of immunosenescence. In this work CMV-induced alterations in the T cell compartment of human individuals were analysed in terms of frequencies and absolute numbers per ml blood. Peripheral blood mononuclear cells (PBMC) from 50 donors in three different age groups were stimulated in vitro and examined for the phenotypic markers CD45RA and CD27 and the effector molecules CD40L, IFNg, IL2 and TNF by polychromatic flow cytometry. The frequency of responding polyfunctional T cells to stimulation with OKT3 or CMV peptide pools phosphoprotein 65 (pp65) or immediate-early protein1 (IE1) increased with the age of the donor. The memory subset distribution differed between CMV-seronegative and CMV-seropositive donors and was correlated with the response size in the CMV-seropositive group. Polyfunctional T cells expressed quantitatively and qualitatively more activation marker on a per cell level than monofunctional cells and therefore appeared to be more effective. Furthermore, polyfunctional T cells expressed reduced amounts of surface CD3, CD4 and CD8 compared to monofunctional or non-responding T cells. In summary, the results indicate that CMV has a significant influence on the immune system of healthy people. The memory subset composition of the entire T cell compartment depends on how the immune system responds to CMV (large or small responses) rather than the presence or absence of infection. Irrespectively of response size or age a robust population of polyfunctional CMV-specific T cells is present and may be in control of CMV
Saison 2024 stechmückenübertragener Krankheitserreger in Deutschland beginnt
No full textZiel ist es mit dem Artikel auf die beginnende Saison stechmückenübertragener Krankheitserreger aufmerksam zu machen. In Deutschland gibt es zwei unterschiedliche Herausforderungen: In Teilen Ostdeutschlands zirkuliert auf der einen Seite seit mehreren Jahren das von heimischen Stechmücken übertragene West-Nil-Virus (im Süden und Südosten der WNV-Endemiegebiete gibt es teilweise Überlappungen mit FSME-Risikogebieten). Auf der anderen Seite breitet sich vor allem in Teilen Süd- und Westdeutschlands die Asiatische Tigermücke weiter aus, die im Prinzip Chikungunya-, Dengue- oder Zikaviren übertragen kann - bisher wurden aber noch keine von ihr übertragenen Infektionen in Deutschland identifiziert. Die entsprechenden Infektionskrankheiten sollten von Ärzten je nach Endemie-/Risikogebiet (WNV, FSME) und Ausbreitungsgebiet (Aedes albopictus) im Sommer und Frühherbst differentialdiagnostisch in Betracht gezogen werden
Emerg Infect Dis
No full textTo validate anecdotal evidence on scabies infestations, we analyzed inpatient and outpatient claims data in Germany. Scabies diagnoses increased 9-fold and treatment failure 4-fold during 2009-2018, driven mainly by persons 15-24 years of age. Prevention and control in young adults appear key because of these persons' high mobility and social connectivity
Starker Anstieg der Denguefieber-Meldefallzahlen in den ersten Monaten 2024
No full textDas in den Tropen und Teilen der Subtropen endemische Denguefieber ist eine akut fieberhafte Erkrankung. Überträger des Denguevirus sind Steckmücken vor allem der Spezies Ae. aegypti oder Ae. albopictus. Während ein Großteil der Infektionen asymptomatisch und selbstlimitierend verläuft, sind auch seltene schwere Verläufe und Todesfälle möglich. Für die ersten Monate des Jahres 2024 wurde bisher eine auffallend hohe reiseassoziierte Denguefieber-Fallzahl gemeldet. Diese ist nicht durch eine erhöhte Reiseaktivität zu erklären. Vielmehr sind die Fallzahlen gerade in vielen Endemiegebieten erhöht und betreffen dort auch Reisende aus Deutschland. Reisenden in Denguevirus-Endemiegebieten wird empfohlen, sich ganztags vor Mückenstichen zu schützen. Reiserückkehrenden in deutschen Regionen mit kompetenten Mückenvektoren wird im Sommer und Frühherbst auch bei Symptomfreiheit bis 14 Tage nach der Reise Mückenschutz empfohlen, um autochthone Übertragungen zu verhindern
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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