In vivo high-resolution structural imaging of large arteries in small rodents using two-photon laser scanning microscopy

In vivo (molecular) imaging of the vessel wall of large arteries at subcellular resolution is crucial for unraveling vascular pathophysiology. We previously showed the applicability of two-photon laser scanning microscopy (TPLSM) in mounted arteries ex vivo. However, in vivo TPLSM has thus far suffered from in-frame and between-frame motion artifacts due to arterial movement with cardiac and respiratory activity. Now, motion artifacts are suppressed by accelerated image acquisition triggered on cardiac and respiratory activity. In vivo TPLSM is performed on rat renal and mouse carotid arteries, both surgically exposed and labeled fluorescently (cell nuclei, elastin, and collagen). The use of short acquisition times consistently limit in-frame motion artifacts. Additionally, triggered imaging reduces between-frame artifacts. Indeed, structures in the vessel wall (cell nuclei, elastic laminae) can be imaged at subcellular resolution. In mechanically damaged carotid arteries, even the subendothelial collagen sheet (~1 µm) is visualized using collagen-targeted quantum dots. We demonstrate stable in vivo imaging of large arteries at subcellular resolution using TPLSM triggered on cardiac and respiratory cycles. This creates great opportunities for studying (diseased) arteries in vivo or immediate validation of in vivo molecular imaging techniques such as magnetic resonance imaging (MRI), ultrasound, and positron emission tomography (PET)

Relations between parental and child separation anxiety: The role of dependency-oriented psychological control

Contains fulltext : 145494.pdf (publisher's version ) (Open Access)Although separation anxiety is prevalent in young children, it remains unclear whether and how maternal separation anxiety is related to separation anxiety in children. This study examined associations between maternal separation anxiety and separation anxiety in children, and the potential effect psychologically controlling parenting. Mothers (N = 269) and children (N = 287) recruited for a community sample participated in two 1-year interval data-waves. Children were aged five-eight and were interviewed using an age-appropriate method for obtaining self-reports of separation anxiety and perceptions of dependency-oriented psychologically controlling parenting. Mothers reported on their feelings of separation anxiety regarding their child via a questionnaire. We found that maternal separation anxiety was positively related to separation anxiety in children within, but not over time. We did not find psychologically controlling parenting to mediate this association. Studying other factors than parenting may be an important avenue for future research in explaining separation anxiety in children.8 p

Polypyrimidine Tract Binding Protein (hnRNP I) Is Possibly a Conserved Modulator of miRNA-Mediated Gene Regulation

MiRNAs can regulate gene expression through versatile mechanisms that result in increased or decreased expression of the targeted mRNA and it could effect the expression of thousands of protein in a particular cell. An increasing body of evidence suggest that miRNAs action can be modulated by proteins that bind to the same 3′UTRs that are targeted by miRNAs, suggesting that other factors apart from miRNAs and their target sites determine miRNA-modulation of gene expression. We applied an affinity purification protocol using biotinylated let-7 miRNA inhibitor to isolate proteins that are involved in let-7 mediated gene regulation that resulted in an affinity purification of Polypyrimidine Tract Binding protein (PTB). Here we show that PTB interacts with miRNAs and human Argonaute 2 (hAgo2) through RNA as well as identified potential mammalian cellular targets that are co-regulated by PTB and hAgo2. In addition, using genetic approach, we have demonstrated that PTB genetically interacts with Caenorhabditis elegans let-7 indicating a conserved role for PTB in miRNA-mediated gene regulation