Non-Contrast-Enhanced MR Arteriography of Potential Living-Related Liver Donor: Using Contrast Enhanced CT Arteriography as Standard Reference.

Background: Contrast-enhanced computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are the primary modalities to assess donors' vessels before transplant surgery. Radiation and contrast medium are potentially harmful to donors.

Purpose: To compare the image quality and visualization scores of hepatic arteries on CTA and balanced steady-state free-precession (bSSFP) non-contrast-enhanced MRA (NC-MRA), and to evaluate if bSSFP NC-MRA can potentially be a substitute for CTA.

Expansion Microscopy-based imaging for visualization of mitochondria in Drosophila ovarian germline stem cells.

Recent studies have shown that mitochondrial morphology can modulate organelle function and greatly affect stem cell behavior, thus affecting tissue homeostasis. As such, we previously showed that the accumulation of fragmented mitochondria in aged Drosophila ovarian germline stem cells (GSCs) contributes to age-dependent GSC loss. However, standard immunofluorescence methods to examine mitochondrial morphology yield images with insufficient resolution for rigorous analysis, while 3-dimensional electron microscopy examination of mitochondrial morphology is labor intensive and allows only limited sampling of mitochondria.

Neural mechanism of spatio-chromatic opponency in the Drosophila amacrine neurons.

Visual animals detect spatial variations of light intensity and wavelength composition. Opponent coding is a common strategy for reducing information redundancy. Neurons equipped with both spatial and spectral opponency have been identified in vertebrates but not yet in insects.

Extrinsic Factors Regulating Dendritic Patterning.

Stereotypic dendrite arborizations are key morphological features of neuronal identity, as the size, shape and location of dendritic trees determine the synaptic input fields and how information is integrated within developed neural circuits. In this review, we focus on the actions of extrinsic intercellular communication factors and their effects on intrinsic developmental processes that lead to dendrite patterning. Surrounding neurons or supporting cells express adhesion receptors and secreted proteins that respectively, act direct contact or over short distances to shape, size, and localize dendrites during specific developmental stages.

Vesicular transport mediates the uptake of cytoplasmic proteins into mitochondria in Drosophila melanogaster.

Mitochondrial aging, which results in mitochondrial dysfunction, is strongly linked to many age-related diseases. Aging is associated with mitochondrial enlargement and transport of cytosolic proteins into mitochondria. The underlying homeostatic mechanisms that regulate mitochondrial morphology and function, and their breakdown during aging, remain unclear.

SNAP29 mediates the assembly of histidine-induced CTP synthase filaments in proximity to the cytokeratin network.

Under metabolic stress, cellular components can assemble into distinct membraneless organelles for adaptation. One such example is cytidine 5'-triphosphate synthase (CTPS, for which there are CTPS1 and CTPS2 forms in mammals), which forms filamentous structures under glutamine deprivation. We have previously demonstrated that histidine (His)-mediated methylation regulates the formation of CTPS filaments to suppress enzymatic activity and preserve the CTPS protein under glutamine deprivation, which promotes cancer cell growth after stress alleviation.

Antagonistic regulation by insulin-like peptide and activin ensures the elaboration of appropriate dendritic field sizes of amacrine neurons.

Establishing appropriate sizes and shapes of dendritic arbors is critical for proper wiring of the central nervous system. Here we report that Insulin-like Peptide 2 (DILP2) locally activates transiently expressed insulin receptors in the central dendrites of Dm8 amacrine neurons to positively regulate dendritic field elaboration. We found DILP2 was expressed in L5 lamina neurons, which have axonal terminals abutting Dm8 dendrites.

An Adult Drosophila Glioma Model for Studying Pathometabolic Pathways of Gliomagenesis.

Glioblastoma multiforme (GBM), the most prevalent brain tumor in adults, has extremely poor prognosis. Frequent genetic alterations that activate epidermal growth factor receptor (EGFR) and phosphatidylinositol-3 kinase (PI3K) signaling, as well as metabolic remodeling, have been associated with gliomagenesis. To establish a whole-animal approach that can be used to readily identify individual pathometabolic signaling factors, we induced glioma formation in the adult Drosophila brain by activating the EGFR-PI3K pathway.

Histidine-Dependent Protein Methylation Is Required for Compartmentalization of CTP Synthase.

CTP synthase (CTPS) forms compartmentalized filaments in response to substrate availability and environmental nutrient status. However, the physiological role of filaments and mechanisms for filament assembly are not well understood. Here, we provide evidence that CTPS forms filaments in response to histidine influx during glutamine starvation.

The human blood DNA methylome identifies crucial role of β-catenin in the pathogenesis of Kawasaki disease.

Kawasaki disease (KD) is a type of acute febrile vasculitis syndrome and is the most frequent cause of cardiac illness in children under the age of five years old. Although the etiology of KD remains largely unknown, some recent genome-wide studies have indicated that epigenetic factors may be important in its pathogenesis. We enrolled 24 KD patients and 24 non-KD controls in this study to access their DNA methylation status using HumanMethylation450 BeadChips.

Diagnosis by simplicity: an aptachip for dopamine capture and accurate detection with a dual colorimetric and fluorometric system.

In this study, we aim to rapidly fabricate an aptachip with a dual colorimetric and fluorometric sensing strategy for easy dopamine (DA) detection with high sensitivity and selectivity. To construct an aptachip with high DA capture efficiency, molecular dynamics (MD) simulations were utilitized to predict the most stable configuration of the DA-binding aptamer (DBA) for DA recognition. The DA in the specimen would be specifically captured on the DBA-aptachip, then released from the DBA in alkaline solution to form DA-quinone (DAQ), thus leading to a color change (from colorless to brown) and inducing a dramatic decrease in the fluorescence intensity as a result of the photoinduced electron transfer (PET) for bovine serum albumin (BSA)-stabilized Au nanoclusters (BSA-Au NCs).

An electrochemical biosensor to simultaneously detect VEGF and PSA for early prostate cancer diagnosis based on graphene oxide/ssDNA/PLLA nanoparticles.

Early diagnosis of prostate cancer (PCa) is critical for the prevention of metastasis and for early treatment; therefore, a simple and accurate device must be developed for this purpose. In this study, we reported a novel fabrication method for producing a dual-modality biosensor that can simultaneously detect vascular endothelial growth factor (VEGF) and prostate-specific antigen (PSA) in human serum for early diagnosis of PCa. This biosensor was constructed by coating graphene oxide/ssDNA (GO-ssDNA) on an Au-electrode for VEGF detection, and incorporated with poly--lactide nanoparticles (PLLA NPs) for signal amplification and PSA detection.

Dynamic labelling of neural connections in multiple colours by trans-synaptic fluorescence complementation.

Determining the pattern of activity of individual connections within a neural circuit could provide insights into the computational processes that underlie brain function. Here, we develop new strategies to label active synapses by trans-synaptic fluorescence complementation in Drosophila. First, we demonstrate that a synaptobrevin-GRASP chimera functions as a powerful activity-dependent marker for synapses in vivo.

Mapping chromatic pathways in the Drosophila visual system.

In Drosophila, color vision and wavelength-selective behaviors are mediated by the compound eye's narrow-spectrum photoreceptors R7 and R8 and their downstream medulla projection (Tm) neurons Tm5a, Tm5b, Tm5c, and Tm20 in the second optic neuropil or medulla. These chromatic Tm neurons project axons to a deeper optic neuropil, the lobula, which in insects has been implicated in processing and relaying color information to the central brain. The synaptic targets of the chromatic Tm neurons in the lobula are not known, however.

A gustatory second-order neuron that connects sucrose-sensitive primary neurons and a distinct region of the gnathal ganglion in the Drosophila brain.

Although the gustatory system provides animals with sensory cues important for food choice and other critical behaviors, little is known about neural circuitry immediately following gustatory sensory neurons (GSNs). Here, we identify and characterize a bilateral pair of gustatory second-order neurons (G2Ns) in Drosophila. Previous studies identified GSNs that relay taste information to distinct subregions of the primary gustatory center (PGC) in the gnathal ganglia (GNG).

Candidate neural substrates for off-edge motion detection in Drosophila.

Background: In the fly's visual motion pathways, two cell types-T4 and T5-are the first known relay neurons to signal small-field direction-selective motion responses [1]. These cells then feed into large tangential cells that signal wide-field motion. Recent studies have identified two types of columnar neurons in the second neuropil, or medulla, that relay input to T4 from L1, the ON-channel neuron in the first neuropil, or lamina, thus providing a candidate substrate for the elementary motion detector (EMD) [2].

Multiple redundant medulla projection neurons mediate color vision in Drosophila.

The receptor mechanism for color vision has been extensively studied. In contrast, the circuit(s) that transform(s) photoreceptor signals into color percepts to guide behavior remain(s) poorly characterized. Using intersectional genetics to inactivate identified subsets of neurons, we have uncovered the first-order interneurons that are functionally required for hue discrimination in Drosophila.

A hard-wired glutamatergic circuit pools and relays UV signals to mediate spectral preference in Drosophila.

Many visual animals have innate preferences for particular wavelengths of light, which can be modified by learning. Drosophila's preference for UV over visible light requires UV-sensing R7 photoreceptors and specific wide-field amacrine neurons called Dm8. Here we identify three types of medulla projection neurons downstream of R7 and Dm8 and show that selectively inactivating one of them (Tm5c) abolishes UV preference.

Photoreceptor-derived activin promotes dendritic termination and restricts the receptive fields of first-order interneurons in Drosophila.

How neurons form appropriately sized dendritic fields to encounter their presynaptic partners is poorly understood. The Drosophila medulla is organized in layers and columns and innervated by medulla neuron dendrites and photoreceptor axons. Here, we show that three types of medulla projection (Tm) neurons extend their dendrites in stereotyped directions and to distinct layers within a single column for processing retinotopic information.

Identification of miR-27b as a novel signature from the mRNA profiles of adipose-derived mesenchymal stem cells involved in the tolerogenic response.

Adipose-derived mesenchymal stem cells (adipose-derived MSCs, ASCs) possess the ability to differentiate into multiple tissue types and have immune-modulatory properties similar to those of MSCs from other origins. However, the regulation of the MSC-elicited immune-modulatory activity by specific microRNA (miRNA) mechanisms remains unexplored. Gene expression profiling with knowledge-based functional enrichment analysis is an appropriate approach for unraveling these mechanisms.

Cis-regulatory complexity within a large non-coding region in the Drosophila genome.

Analysis of cis-regulatory enhancers has revealed that they consist of clustered blocks of highly conserved sequences. Although most characterized enhancers reside near their target genes, a growing number of studies have shown that enhancers located over 50 kb from their minimal promoter(s) are required for appropriate gene expression and many of these 'long-range' enhancers are found in genomic regions that are devoid of identified exons. To gain insight into the complexity of Drosophila cis-regulatory sequences within exon-poor regions, we have undertaken an evolutionary analysis of 39 of these regions located throughout the genome.

Use of a Drosophila genome-wide conserved sequence database to identify functionally related cis-regulatory enhancers.

Background: Phylogenetic footprinting has revealed that cis-regulatory enhancers consist of conserved DNA sequence clusters (CSCs). Currently, there is no systematic approach for enhancer discovery and analysis that takes full-advantage of the sequence information within enhancer CSCs.

Results: We have generated a Drosophila genome-wide database of conserved DNA consisting of >100,000 CSCs derived from EvoPrints spanning over 90% of the genome.

Focusing transgene expression in Drosophila by coupling Gal4 with a novel split-LexA expression system.

Here we report the development of a ternary version of the LexA::VP16/LexAop system in which the DNA-binding and trans-activating moieties are independently targeted using distinct promoters to achieve highly restricted, intersectional expression patterns. This Split LexA system can be concatenated with the Gal4/upstream activating sequence system to refine the expression patterns of existing Gal4 lines with minimal genetic manipulations.

Abi plays an opposing role to Abl in Drosophila axonogenesis and synaptogenesis.

Abl tyrosine kinase (Abl) regulates axon guidance by modulating actin dynamics. Abelson interacting protein (Abi), originally identified as a kinase substrate of Abl, also plays a key role in actin dynamics, yet its role with respect to Abl in the developing nervous system remains unclear. Here we show that mutations in abi disrupt axonal patterning in the developing Drosophila central nervous system (CNS).

The involvement of Abl and PTP61F in the regulation of Abi protein localization and stability and lamella formation in Drosophila S2 cells.

Most aspects of cellular events are regulated by a series of protein phosphorylation and dephosphorylation processes. Abi (Abl interactor protein) functions as a substrate adaptor protein for Abl and a core member of the WAVE complex, relaying signals from Rac to Arp2/3 complex and regulating actin dynamics. It is known that the recruitment of Abi into the lamella promotes polymerization of actin, although how it does this is unclear.