Klinik und Poliklinik fĂĽr Kinder- und Jugendmedizin
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Background
The role of platelets for mediating closure of the ductus arteriosus in human preterm infants is controversial. Especially, the effect of low platelet counts on pharmacological treatment failure is still unclear.
Methods
In this retrospective study of 471 preterm infants [<1,500 g birth weight (BW)], who were treated for a patent ductus arteriosus (PDA) with indomethacin or ibuprofen, we investigated whether platelet counts before or during pharmacological treatment had an impact on the successful closure of a hemodynamically significant PDA. The effects of other factors, such as sepsis, preeclampsia, gestational age, BW, and gender, were also evaluated.
Results
Platelet counts before initiation of pharmacological PDA treatment did not differ between infants with later treatment success or failure. However, we found significant associations between low platelet counts during pharmacological PDA therapy and treatment failure (p < 0.05). Receiver operating characteristic (ROC) curve analysis showed that platelet counts after the first, and before and after the second cyclooxygenase inhibitor (COXI) cycle were significantly associated with treatment failure (area under the curve of >0.6). However, ROC curve analysis did not reveal a specific platelet cutoff-value that could predict PDA treatment failure. Multivariate logistic regression analysis showed that lower platelet counts, a lower BW, and preeclampsia were independently associated with COXI treatment failure.
Conclusion
We provide further evidence for an association between low platelet counts during pharmacological therapy for symptomatic PDA and treatment failure, while platelet counts before initiation of therapy did not affect treatment outcome.
Objective: We performed a pilot RCT to prove the hypothesis that a controlled ingestion of polyphenol-rich beverages (soy drink, decaffeinated black tea) in nutritive dosages by nursing women has an effect on the composition (flavonoid concentration, total antioxidant capacity) of breast milk. Methods: Healthy nursing women were supplemented with either 250 mL of a soy drink (12 mg isoflavones; n = 18), 300 mL decaffeinated black tea (67 mg catechins; n = 18), or 300 mL water (n = 8, control) for 6 days. Milk samples were collected before, during, and after intervention. Flavonoid content (isoflavones/catechins, HPLC) and total antioxidant capacity of milk and test drinks in milk specimens were assessed. Results: Isoflavone content (genistein and daidzein) in breast milk increased up to 12 nmol/L after soy drink consumption; the major flavonoids constituents of black tea (catechin, epicatechin, and respective conjugates) could not be detected in milk samples. With both interventions, the total antioxidant capacity of breast milk was not affected. Conclusions: Mothers' daily consumption of a soy drink considerably increases isoflavone content of breast milk resulting in an estimated daily exposure of 9.6 nmol isoflavones in a 4-month-old suckling infant. Luminal flavanol uptake from black tea consumed by the nursing mother may be too low to affect flavanol concentrations in breast milk.
Hyperoxia is a well-known cause of cerebral white matter injury in preterm infants with male sex being an independent and critical risk factor for poor neurodevelopmental outcome. We investigated the underlying mechanisms behind such a sex dependent difference in oligodendrocyte progenitor cells (OPCs). Our findings demonstrate that oxidative stress severely affects cellular functions related to energy metabolism, stress response, and maturation in male derived oligodendrocyte progenitor cells (OPCs) whereas the female cells remain largely unaffected. This impairment of maturation is accompanied by the downregulation of nucleoporin and nuclear lamina proteins. We identify Nup133, which regulates OPC maturation as a major target protein affected by hyperoxia in male cells and that this differential response is mediated by an inverse Nup133 regulation in the male and female cells. It also regulates mitochondrial function and oxidative stress response through its downstream target Nuclear respiratory factor 1 (Nrf1). Additionally, the presence of 17-β estradiol and higher amounts of fetal zone steroids (precursors for maternal estrogen synthesis during fetal development) confer resistance to the female cells mediated by the estrogen receptor alpha (ERα) along with Nup133. Both Nup133 and ERα regulate mitochondrial function and oxidative stress response by transcriptional regulation of Nrf1. These findings establish prominent sex based differences and the molecular mechanisms involved in differential response of OPCs towards oxidative stress and the important role of Nup133 in mediating a severe negative outcome in the male cells.
Human cytomegalovirus (HCMV) latency is typically harmless but reactivation can be largely detrimental to immune compromised hosts. We modeled latency and reactivation using a traceable HCMV laboratory strain expressing the Gaussia luciferase reporter gene (HCMV/GLuc) in order to interrogate the viral modulatory effects on the human adaptive immunity. Humanized mice with long-term (more than 17 weeks) steady human T and B cell immune reconstitutions were infected with HCMV/GLuc and 7 weeks later were further treated with granulocyte-colony stimulating factor (G-CSF) to induce viral reactivations. Whole body bio-luminescence imaging analyses clearly differentiated mice with latent viral infections vs. reactivations. Foci of vigorous viral reactivations were detectable in liver, lymph nodes and salivary glands. The number of viral genome copies in various tissues increased upon reactivations and were detectable in sorted human CD14+, CD169+, and CD34+ cells. Compared with non-infected controls, mice after infections and reactivations showed higher thymopoiesis, systemic expansion of Th, CTL, Treg, and Tfh cells and functional antiviral T cell responses. Latent infections promoted vast development of memory CD4+ T cells while reactivations triggered a shift toward effector T cells expressing PD-1. Further, reactivations prompted a marked development of B cells, maturation of IgG+ plasma cells, and HCMV-specific antibody responses. Multivariate statistical methods were employed using T and B cell immune phenotypic profiles obtained with cells from several tissues of individual mice. The data was used to identify combinations of markers that could predict an HCMV infection vs. reactivation status. In spleen, but not in lymph nodes, higher frequencies of effector CD4+ T cells expressing PD-1 were among the factors most suited to distinguish HCMV reactivations from infections. These results suggest a shift from a T cell dominated immune response during latent infections toward an exhausted T cell phenotype and active humoral immune response upon reactivations. In sum, this novel in vivo humanized model combined with advanced analyses highlights a dynamic system clearly specifying the immunological spatial signatures of HCMV latency and reactivations. These signatures can be merged as predictive biomarker clusters that can be applied in the clinical translation of new therapies for the control of HCMV reactivation.
Introduction
Primary immunodeficiency disorders (PIDs) are a heterogeneous group of more than 200 rare diseases. Timely diagnosis is of uttermost importance. Therefore, we aimed to develop a diagnostic questionnaire with computerized pattern-recognition in order to support physicians to identify suspicious patient histories.
Materials and methods
Standardized interviews were conducted with guardians of children with PID. The questionnaire based on parental observations was developed using Colaizzis’ framework for content analysis. Answers from 64 PID patients and 62 controls were analyzed by data mining methods in order to make a diagnostic prediction. Performance was evaluated by k-fold stratified cross-validation.
Results
The diagnostic support tool achieved a diagnostic sensitivity of up to 98%. The analysis of 12 interviews revealed 26 main phenomena observed by parents in the pre-diagnostic period. The questions were systematically phrased and selected resulting in a 36-item questionnaire. This was answered by 126 patients with or without PID to evaluate prediction. Item analysis revealed significant questions.
Discussion
Our approach proved suitable for recognizing patterns and thus differentiates between observations of PID patients and control groups. These findings provide the basis for developing a tool supporting physicians to consider a PID with a questionnaire. These data support the notion that patient’s experience is a cornerstone in the diagnostic process.
Das Immunsystem des Neugeborenen unterscheidet sich grundlegend von
dem des Erwachsenen. Aufgrund der unvollständig entwickelten adaptiven
Immunantwort sind Neonaten einer erhöhten Infektionsgefahr ausgesetzt,
während sie vorrangig auf das innate Immunsystem bei der Abwehr von
Erregern zurĂĽckgreifen mĂĽssen. Einen wesentlichen Bestandteil dieser
angeborenen Immunabwehr stellen die neutrophilen Granulozyten dar, die
unter anderem in Form der Phagozytose die Bekämpfung von Pathogenen
im Gewebe realisieren.
Eine weitere, 2004 beschriebene Funktion der Neutrophilen ist die Bildung von „Neutrophil Extracellular Traps“ (NETs). Bei dieser speziellen Form des Zelltods, die auch als NETose bezeichnet wird, nutzen die neutrophilen Granulozyten ihre DNA und intrazelluläre Proteine, um antimikrobiell wirksame, netzförmige Strukturen in den Extrazellularraum auszuwerfen. Diese sind dort in der Lage, Pathogene zu binden und zu zerstören. Ziel dieser Arbeit war, die NETose bei Neugeborenen im Vergleich zu Erwachsenen zu untersuchen und wichtige perinatale Einflussfaktoren auf die NETose zu charakterisieren.
Die Neutrophilen wurden aus Nabelschnurblut isoliert und anschlieĂźend
mit entsprechenden Stimuli zur NETose angeregt. Die ausgeworfene DNA
wurde angefärbt, mittels Fluoreszenzmikroskopie analysiert und die
Ergebnisse hinsichtlich Anzahl und Größe der NETs ausgewertet.
In der vorliegenden Studie konnte gezeigt werden, dass die NETose bei
Neugeborenen im Vergleich zu Erwachsenen signifikant vermindert ist.
DarĂĽber hinaus wurde ein Zusammenhang mit dem Gestationsalter
festgestellt, so wiesen unreife gegenüber reifen Neugeborenen ebenfalls eine eingeschränkte NET-Fähigkeit auf. Ferner wurde der Einfluss weiterer Parameter beleuchtet, wie des Geburtsgewichts und des -modus, des Geschlechts oder einer perinatalen Infektion.
Die verminderte Fähigkeit zur NETose ist Teil der unvollständig
entwickelten Immunantwort bei Neugeborenen und könnte so zu deren
Infektionsanfälligkeit beitragen.
