50 research outputs found

    Developmental expression profile of the yy2 gene in mice

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    <p>Abstract</p> <p>Background</p> <p>The transcription factor Yin Yang 2 (YY2) shares a structural and functional highly homologue DNA-binding domain with the ubiquitously expressed YY1 protein, which has been implicated in regulating fundamental biological processes. However, the biological relevance of YY2 has not been identified yet.</p> <p>Results</p> <p>Towards the understanding of YY2 biology, we analyzed in detail the expression pattern of <it>yy</it>2 in various organs during embryonic and postnatal mouse development till adulthood. Thereby, a constant <it>yy2 </it>level was detected in heart and lung tissue, whereas in different brain regions <it>yy2 </it>expression was dynamically regulated. Interestingly, in any analyzed tissue neither the homologue <it>yy1 </it>nor the <it>mbtps2 </it>gene showed changes in mRNA expression levels like <it>yy2</it>, although the intronless <it>yy2 </it>gene is located within the <it>mbtps2 </it>locus.</p> <p>Furthermore, we detected <it>yy1</it>, <it>yy2</it>, and <it>mbtps2 </it>mRNA in primary mouse neurons, microglia cells, and astrocytes. In comparison to <it>yy2 </it>and <it>mbtps2</it>, <it>yy1 </it>revealed the highest expression level in all cell types. Again, only <it>yy2 </it>showed significantly altered gene expression levels among the cell types. Higher <it>yy2 </it>expression levels were detected in microglia cells and astrocytes than in primary neurons.</p> <p>Conclusion</p> <p><it>Yy</it>2 expression in the heart and lung is constitutively expressed during embryogenesis and in adult mice. For the first time, developmental changes of <it>yy2 </it>transcription became obvious in various areas of the brain. This suggests that yy2 is involved in developmental gene regulation.</p

    Never too late? Quadruplets at the age of 65 years

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    Background: We discuss the challenges of multiple pregnancy at very advanced reproductive age. Case presentation: We present the case of a quadruplet pregnancy at the maternal age of 65 following in-vitro fertilization (IVF) with donor eggs and sperm, involving cross-border reproductive care. All children born were at 25 weeks' gestation and survived; however, poor neurodevelopmental outcome remains a major concern in one child. Conclusions: The use of reproductive technology to achieve a multiple pregnancy at such an advanced post-menopausal age generated a debate on ethical, psychosocial and medical questions. We share this debate and highlight the need to reconsider international guidelines for women of advanced reproductive age

    Expression pattern of the thrombopoietin receptor (Mpl) in the murine central nervous system

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    <p>Abstract</p> <p>Background</p> <p>Thrombopoietin (Thpo) and its receptor (Mpl), which regulate megakaryopoiesis, are expressed in the central nervous system (CNS), where Thpo is thought to exert pro-apoptotic effects on newly generated neurons. Mpl expression has been analysed in brain tissue on transcript level and in cultured primary rat neurons and astrocytes on protein level. Herein, we analysed Mpl expression in the developing and adult murine CNS by immunohistochemistry and investigated the brain of mice with homozygous <it>Mpl </it>deficiency (<it>Mpl</it><sup>-/-</sup>) by MRI.</p> <p>Results</p> <p>Mpl was not detectable at developmental stages E12 to E15 in any resident cells of the CNS. From E18 onwards, robust Mpl expression was found in various brain areas, including cerebral cortex, olfactory bulb, thalamus, hypothalamus, medulla, pons, and the grey matter of spinal cord. However, major developmental changes became obvious: In the subventricular zone of the cerebral cortex Mpl expression occurred only during late gestation, while in the hippocampus Mpl expression was detectable for first time at stage P4. In the white matter of the cerebellum Mpl expression was restricted to the perinatal period. In the adult cerebellum, Mpl expression switched to Purkinje cell. The majority of other Mpl-positive cells were NeuN-positive neurons. None of the cells could be double-labelled with astrocyte marker GFAP. <it>Mpl</it><sup>-/- </sup>mice showed no gross abnormalities of the brain.</p> <p>Conclusions</p> <p>Our data locate Mpl expression to neurons at different subdivisions of the spinal cord, rhombencephalon, midbrain and prosencephalon. Besides neuronal cells Mpl protein is also expressed in Purkinje cells of the adult cerebellum.</p

    The Erythropoietin Promoter Variant rs1617640 Is Not Associated with Severe Retinopathy of Prematurity, Independent of Treatment with Erythropoietin

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    In this case-control study, the erythropoietin (EPO) promoter variant s1617640, linked to high intravitreal EPO concentrations and increased risk of diabetic retinopathy, was not associated with severe retinopathy of prematurity. This finding was observed both in infants with and without recombinant EPO administration

    Validation of a New PCR-Based Screening Method for Prevention of Serratia marcescens Outbreaks in the Neonatal Intensive Care Unit

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    Background: Serratia marcescens may cause severe nosocomial infections, mostly in very low birth weight infants. Since S. marcescens exhibits by far the highest adjusted incidence rate for horizontal transmission, it can cause complex outbreak situations in neonatal intensive care units. Objective: The aim of this study was to establish a fast and highly sensitive colonization screening for prompt cohorting and barrier nursing strategies. Methods: A probe-based duplex PCR assay targeting the 16S rRNA gene of S. marcescens was developed and validated by using 36 reference strains, 14 S. marcescens outbreak- and nonoutbreak isolates, defined by epidemiological linkage and molecular typing, and applied in 1,347 clinical specimens from 505 patients. Results and Conclusions: The novel PCR assay proved to be highly specific and had an in vitro sensitivity of 100 gene copies per reaction (∌15 bacteria). It showed a similar (in laryngeal/tracheal specimens) or even higher (in rectal/stoma swabs) in vivo sensitivity in comparison to routine microbial culture and was much quicker (<24 h vs. 2 days). By combining different oligonucleotide primers, there was robust detection of genetic variants of S. marcescens strains. PCR inhibition was low (1.6%) and observed with rectal swabs only. Cohort analysis illustrated applicability of the PCR assay as a quick tool to prevent outbreak scenarios by allowing rapid decisions on cohorting and barrier nursing. In summary, this novel molecular screening for colonization by S. marcescens is specific, highly sensitive, and substantially accelerates detection

    The circadian clock regulates rhythmic erythropoietin expression in the murine kidney

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    Generation of circadian rhythms is cell-autonomous and relies on a transcription/translation feedback loop controlled by a family of circadian clock transcription factor activators including CLOCK, BMAL1 and repressors such as CRY1 and CRY2. The aim of the present study was to examine both the molecular mechanism and the hemopoietic implication of circadian erythropoietin expression. Mutant mice with homozygous deletion of the core circadian clock genes cryptochromes 1 and 2 (Cry-null) were used to elucidate circadian erythropoietin regulation. Wild-type control mice exhibited a significant difference in kidney erythropoietin mRNA expression between circadian times 06 and 18. In parallel, a significantly higher number of erythropoietin-producing cells in the kidney (by RNAscopeÂź) and significantly higher levels of circulating erythropoietin protein (by ELISA) were detected at circadian time 18. Such changes were abolished in Cry-null mice and were independent from oxygen tension, oxygen saturation, or expression of hypoxia-inducible factor 2 alpha, indicating that circadian erythropoietin expression is transcriptionally regulated by CRY1 and CRY2. Reporter gene assays showed that the CLOCK/BMAL1 heterodimer activated an E-box element in the 5' erythropoietin promoter. RNAscopeÂź in situ hybridization confirmed the presence of Bmal1 in erythropoietin-producing cells of the kidney. In Cry-null mice, a significantly reduced number of reticulocytes was found while erythrocyte numbers and hematocrit were unchanged. Thus, circadian erythropoietin regulation in the normoxic adult murine kidney is transcriptionally controlled by master circadian activators CLOCK/BMAL1, and repressors CRY1/CRY2. These findings may have implications for kidney physiology and disease, laboratory diagnostics, and anemia therapy

    Pooling, room temperature, and extended storage time increase the release of adult‐specific biologic response modifiers in platelet concentrates: a hidden transfusion risk for neonates?

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    BACKGROUND: Adult donor platelets (PLTs) are frequently transfused to prevent or stop bleeding in neonates with thrombocytopenia. There is evidence for PLT transfusion-related morbidity and mortality, leading to the hypothesis on immunomodulatory effects of transfusing adult PLTs into neonates. Candidate factors are biologic response modifiers (BRMs) that are expressed at higher rates in adult than in neonatal PLTs. This study investigated whether storage conditions or preparation methods impact on the release of those differentially expressed BRMs. STUDY DESIGN AND METHODS: Pooled PLT concentrates (PCs) and apheresis PCs (APCs) were stored under agitation for up to 7 days at room temperature (RT) or at 2 to 8 degrees C. The BRMs CCL5/RANTES, TGF beta 1, TSP1, and DKK1 were measured in PCs' supernatant, lysate, and corresponding plasma. PLT function was assessed by light transmission aggregometry. RESULTS: Concerning the preparation method, higher concentrations of DKK1 were found in pooled PCs compared to APCs. In supernatants, the concentrations of CCL5, TGF beta 1, TSP1, and DKK1 significantly increased, both over standard (≀ 4 days) and over extended storage times (7 days). Each of the four BRMs showed an up to twofold increase in concentration after storage at RT compared to cold storage (CS). There was no difference in the aggregation capacity. CONCLUSION: This analysis shows that the release of adult-specific BRMs during storage is lowest in short- and CS APCs. Our study points to strategies for reducing the exposure of sick neonates to BRMs that can be specifically associated to PLT transfusion-related morbidity

    Independent effects of sham laparotomy and anesthesia on hepatic microRNA expression in rats

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    Background: Studies on liver regeneration following partial hepatectomy (PH) have identified several microRNAs (miRNAs) that show a regulated expression pattern. These studies involve major surgery to access the liver, which is known to have intrinsic effects on hepatic gene expression and may also affect miRNA screening results. We performed two-third PH or sham laparotomy (SL) in Wistar rats to investigate the effect of both procedures on miRNA expression in liver tissue and corresponding plasma samples by microarray and qRT-PCR analyses. As control groups, non-treated rats and rats undergoing anesthesia only were used. Results: We found that 49 out of 323 miRNAs (15%) were significantly deregulated after PH in liver tissue 12 to 48 hours postoperatively (>20% change), while 45 miRNAs (14%) were deregulated following SL. Out of these miRNAs, 10 miRNAs were similarly deregulated after PH and SL, while one miRNA showed opposite regulation. In plasma, miRNA upregulation was observed for miR-133a and miR-133b following PH and SL, whereas miR-100 and miR-466c were similarly downregulated following anesthesia and surgery. Conclusions: We show that miRNAs are indeed regulated by sham laparotomy and anesthesia in rats. These findings illustrate the critical need for finding appropriate control groups in experimental surgery
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