244 research outputs found

    Development of Morphological Diversity of Dendrites in Drosophila by the BTB-Zinc Finger Protein Abrupt

    Get PDF
    Morphological diversity of dendrites contributes to specialized functions of individual neurons. In the present study, we examined the molecular basis that generates distinct morphological classes of Drosophila dendritic arborization (da) neurons. da neurons are classified into classes I to IV in order of increasing territory size and/or branching complexity. We found that Abrupt (Ab), a BTB-zinc finger protein, is expressed selectively in class I cells. Misexpression of ab in neurons of other classes directed them to take the appearance of cells with smaller and/or less elaborated arbors. Loss of ab functions in class I neurons resulted in malformation of their typical comb-like arbor patterns and generation of supernumerary branch terminals. Together with the results of monitoring dendritic dynamics of ab-misexpressing cells or ab mutant ones, all of the data suggested that Ab endows characteristics of dendritic morphogenesis of the class I neurons

    X-ray Anomalous Scattering of Diluted Magnetic Oxide Semiconductors: Possible Evidence of Lattice Deformation for High Temperature Ferromagnetism

    Full text link
    We have examined whether the Co ions crystallographically substitute on the Ti sites in rutile and anatase Ti_{1-x}CoCo_{x}OO_{2-delta}thinfilmsthatexhibitroomtemperatureferromagnetism.IntensitiesofthexrayBraggreflectionfromthefilmsweremeasuredaroundthe thin films that exhibit room-temperature ferromagnetism. Intensities of the x-ray Bragg reflection from the films were measured around the KabsorptionedgeofCo.IftheCoionsrandomlysubstituteontheTisites,theintensityshouldexhibitananomalyduetotheanomalousdispersionoftheatomicscatteringfactorofCo.However,noneoftheanataseandrutilesamplesdidexhibitananomaly,unambiguouslyshowingthattheCoionsinTi-absorption-edge of Co. If the Co ions randomly substitute on the Ti sites, the intensity should exhibit an anomaly due to the anomalous dispersion of the atomic scattering factor of Co. However, none of the anatase and rutile samples did exhibit an anomaly, unambiguously showing that the Co ions in Ti_{1-x}CoCo_{x}OO_{2-delta}arenotexactlylocatedattheTisitesofTiO are not exactly located at the Ti sites of TiO_2.TheabsenceoftheanomalyisprobablycausedbyasignificantdeformationofthelocalstructurearoundCoduetotheoxygenvacancy.WehaveappliedthesamemethodtoparamagneticZn. The absence of the anomaly is probably caused by a significant deformation of the local structure around Co due to the oxygen vacancy. We have applied the same method to paramagnetic Zn_{1-x}CoCo_{x}$O thin films and obtained direct evidence that the Co ions are indeed substituted on the Zn sites.Comment: 5 pages, 4 figures, accepted in PR

    Ultrafiltration attenuates cardiopulmonary bypass–induced acute lung injury in a canine model of single-lung transplantation

    Get PDF
    ObjectiveThe purpose of this study was to investigate the effects of cardiopulmonary bypass and ultrafiltration on graft function in a canine single-lung transplantation model.MethodsFifteen left single-lung transplantations were done in weight-mismatched canine pairs. The animals were divided into 3 groups: group 1, in which transplantation was done without cardiopulmonary bypass; group 2, in which transplantation was done with cardiopulmonary bypass and in which the cardiopulmonary bypass flow was decreased slowly with controlled pulmonary artery pressure; and group 3, in which transplantation was done with cardiopulmonary bypass and ultrafiltration. Hemodynamic parameters and lung function were monitored for 6 hours after reperfusion. The grafts were harvested for histologic studies, myeloperoxidase assay, and real-time quantitive reverse transcription–polymerase chain reaction of mRNA encoding interleukin 6.ResultsThe hemodynamic parameters were similar among the 3 groups. In group 1 Pao2 and alveolar to arterial gradient for O2 levels were excellent throughout the 6-hour observation period, but in group 2 they progressively deteriorated. However, ultrafiltration significantly (P = .02) improved the Pao2 level in group 3. On histology, interstitial edema and polynuclear cell infiltration were most marked in group 2 and significantly worse than in groups 1 and 3. Myeloperoxidase assay and real-time quantitative reverse transcription–polymerase chain reaction showed increased myeloperoxidase activity and interleukin 6 gene expression in group 2 grafts compared with group 1 grafts. Myeloperoxidase activity and interleukin 6 gene expression were suppressed with ultrafiltration.ConclusionsCardiopulmonary bypass had negative effects on the graft, but ultrafiltration attenuated acute lung dysfunction by reducing the inflammatory response

    Transarterial embolization for convexity dural arteriovenous fistula

    Get PDF
    Background: Convexity dural arteriovenous fistulae (dAVF) usually reflux into cortical veins without involving the venous sinuses. Although direct drainage ligation is curative, transarterial embolization (TAE) may be an alternative treatment. Case Description: Between September 2018 and January 2021, we encountered four patients with convexity dAVFs. They were three males and one female; their age ranged from 36 to 73 years. The initial symptom was headache (n = 1) or seizure (n = 2); one patient was asymptomatic. In all patients, the feeders were external carotid arteries with drainage into the cortical veins; in two patients, there was pial arterial supply from the middle cerebral artery. All patients were successfully treated by TAE alone using either Onyx or N-butyl cyanoacrylate embolization. Two patients required two sessions. All dAVFs were completely occluded and follow-up MRI or angiograms confirmed no recurrence. Conclusion: Our small series suggests that TAE with a liquid embolic material is an appropriate first-line treatment in patients with convexity dAVFs with or without pial arterial supply

    Nilvadipine attenuates ischemic degradation of gerbil brain cytoskeletal proteins. Stroke

    Get PDF
    A ccumulating evidence shows that calcium L \ channel blockers have protective effects J. \ , against cerebral ischemia, 1 and this protection has been attributed not only to the vascular effects of these drugs 2 but also to their direct effects on nervous tissue. 3 Nilvadipine, 4 a new dihydropyridine-derived calcium channel blocker, possesses advantages over known blockers in having a selective relaxant effect on the basilar artery and prolonged facilitation of blood flow. A previous study has shown that nilvadipine was effective in reducing ischemia in models of chronic coronary artery occlusion in dogs

    Increase in Cellulose Accumulation and Improvement of Saccharification by Overexpression of Arabinofuranosidase in Rice

    Get PDF
    Cellulosic biomass is available for the production of biofuel, with saccharification of the cell wall being a key process. We investigated whether alteration of arabinoxylan, a major hemicellulose in monocots, causes an increase in saccharification efficiency. Arabinoxylans have β-1,4-D-xylopyranosyl backbones and 1,3- or 1,4-α-l-arabinofuranosyl residues linked to O-2 and/or O-3 of xylopyranosyl residues as side chains. Arabinose side chains interrupt the hydrogen bond between arabinoxylan and cellulose and carry an ester-linked feruloyl substituent. Arabinose side chains are the base point for diferuloyl cross-links and lignification. We analyzed rice plants overexpressing arabinofuranosidase (ARAF) to study the role of arabinose residues in the cell wall and their effects on saccharification. Arabinose content in the cell wall of transgenic rice plants overexpressing individual ARAF full-length cDNA (OsARAF1-FOX and OsARAF3-FOX) decreased 25% and 20% compared to the control and the amount of glucose increased by 28.2% and 34.2%, respectively. We studied modifications of cell wall polysaccharides at the cellular level by comparing histochemical cellulose staining patterns and immunolocalization patterns using antibodies raised against α-(1,5)-linked l-Ara (LM6) and β-(1,4)-linked d-Xyl (LM10 and LM11) residues. However, they showed no visible phenotype. Our results suggest that the balance between arabinoxylan and cellulose might maintain the cell wall network. Moreover, ARAF overexpression in rice effectively leads to an increase in cellulose accumulation and saccharification efficiency, which can be used to produce bioethanol

    Localization of ASV Integrase-DNA Contacts by Site-Directed Crosslinking and their Structural Analysis

    Get PDF
    We applied crosslinking techniques as a first step in preparation of stable avian sarcoma virus (ASV) integrase (IN)-DNA complexes for crystallographic investigations. These results were then compared with the crystal structures of the prototype foamy virus (PFV) intasome and with published data for other retroviral IN proteins.Photoaffinity crosslinking and site-directed chemical crosslinking were used to localize the sites of contacts with DNA substrates on the surface of ASV IN. Sulfhydryl groups of cysteines engineered into ASV IN and amino-modified nucleotides in DNA substrates were used for attachment of photocrosslinkers. Analysis of photocrosslinking data revealed several specific DNA-protein contacts. To confirm contact sites, thiol-modified nucleotides were introduced into oligo-DNA substrates at suggested points of contact and chemically crosslinked to the cysteines via formation of disulfide bridges. Cysteines incorporated in positions 124 and 146 in the ASV IN core domain were shown to interact directly with host and viral portions of the Y-mer DNA substrate, respectively. Crosslinking of an R244C ASV IN derivative identified contacts at positions 11 and 12 on both strands of viral DNA. The most efficient disulfide crosslinking was observed for complexes of the ASV IN E157C and D64C derivatives with linear viral DNA substrate carrying a thiol-modified scissile phosphate.Analysis of our crosslinking results as well as published results of retroviral IN protein from other laboratories shows good agreement with the structure of PFV IN and derived ASV, HIV, and MuLV models for the core domain, but only partial agreement for the N- and C-terminal domains. These differences might be explained by structural variations and evolutionary selection for residues at alternate positions to perform analogous functions, and by methodological differences: i.e., a static picture of a particular assembly from crystallography vs. a variety of interactions that might occur during formation of functional IN complexes in solution
    corecore