oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 512 )

2018 ( 818 )

2017 ( 843 )

2016 ( 1105 )

Custom range...

Search Results: 1 - 10 of 479635 matches for " S. L. Bathgate "
All listed articles are free for downloading (OA Articles)
Page 1 /479635
Display every page Item
Moyamoya Disease in Pregnancy: Management after Intracranial Bypass Grafting
A. C. Gimovsky,C. J. Macri,S. L. Bathgate,D. E. Ross
Case Reports in Obstetrics and Gynecology , 2012, DOI: 10.1155/2012/638471
Abstract: Moyamoya disease (MD) is a chronic, progressive cerebrovascular disease distinguished by bilateral stenosis or occlusion of the arteries around the circle of Willis with resulting prominent arterial collateral circulation. We describe a pregnant woman in whom this diagnosis was confirmed by cerebral angiogram and treated with bilateral superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting prior to conception. The patient was managed with strict blood pressure monitoring and low-dose aspirin antepartum, intrapartum, and postpartum. The patient presented in spontaneous labor at term and underwent a spontaneous vaginal delivery without complications.
Moyamoya Disease in Pregnancy: Management after Intracranial Bypass Grafting
A. C. Gimovsky,C. J. Macri,S. L. Bathgate,D. E. Ross
Case Reports in Obstetrics and Gynecology , 2012, DOI: 10.1155/2012/638471
Abstract: Moyamoya disease (MD) is a chronic, progressive cerebrovascular disease distinguished by bilateral stenosis or occlusion of the arteries around the circle of Willis with resulting prominent arterial collateral circulation. We describe a pregnant woman in whom this diagnosis was confirmed by cerebral angiogram and treated with bilateral superficial temporal artery-middle cerebral artery (STA-MCA) bypass grafting prior to conception. The patient was managed with strict blood pressure monitoring and low-dose aspirin antepartum, intrapartum, and postpartum. The patient presented in spontaneous labor at term and underwent a spontaneous vaginal delivery without complications. 1. Introduction MD is a progressive cerebrovascular disease distinguished by bilateral stenosis or occlusion of the arteries supplying the circle of Willis and resulting in a prominent arterial collateral circulation. The disease is characterized by intimal thickening in the walls of the internal carotid arteries bilaterally. Intraventricular, subarachnoid, and intracerebral hemorrhage has been described with MD. There is a paucity of the literature regarding management during pregnancy. We present a case of a woman with MD who underwent intracranial bypass grafting prior to conception and subsequently underwent a successful vaginal delivery. 2. Case A 30-year-old right-handed African American presented for prenatal care at 10 weeks of gestation. The patient had a past medical history that was significant for a “stroke” in 1999. In 2008, the patient presented to the emergency department (ED) with difficulty using her right hand and transient left-sided weakness and numbness. A preliminary diagnosis of transient ischemic attack (TIA) was made. Her evaluation at that time included an MRI which demonstrated encephalomalacia in the right frontal cortex; MRA at that time demonstrated “irregular vessels” but was otherwise interpreted as unremarkable. A follow-up evaluation by a neurosurgeon confirmed the diagnosis of MD based upon findings at a cerebral angiogram. Please see Figures 1(a) and 1(b) for images from her cerebral angiogram. The patient underwent bilateral STA-MCA bypass grafting. One month following the second procedure the patient presented to the ED with aphasia and right hemiplegia. Evaluation revealed a left basal ganglia hemorrhage. Her symptoms subsequently resolved. Figure 1: The attached pictures are digitally subtracted images from a cerebral angiogram of our patient. (a) Right vertebral injection showing irregular, serpiginous ill-defined vessels. (b) Left vertebral
Care of HIV-Infected Pregnant Women in Maternal–Fetal Medicine Programs
Peter A. Sklar,Susanne L. Bathgate,Heather A. Young,David M. Parenti
Infectious Diseases in Obstetrics and Gynecology , 2001, DOI: 10.1155/s1064744901000151
Abstract: Objective: To survey the evolution over the past decade of attitudes and practices of obstetricians in maternal–fetal medicine fellowship programs regarding the management of human immunodeficiency virus (HIV)-infected pregnant women.
Examination of relaxin and its receptors expression in pig gametes and embryos
Jean M Feugang, Juan C Rodriguez-Munoz, Scott T Willard, Ross A Bathgate, Peter L Ryan
Reproductive Biology and Endocrinology , 2011, DOI: 10.1186/1477-7827-9-10
Abstract: Immature cumulus-oocyte complexes (COCs) were aspirated from sows' ovaries collected at the abattoir. After in vitro-maturation, COCs were in vitro-fertilized and cultured. For studies, immature and mature COCs were separately collected, and oocytes were freed from their surrounding cumulus cells. Denuded oocytes, cumulus cells, mature boar spermatozoa, zygotes, and embryos (cleaved and blastocysts) were harvested for temporal and spatial gene expression studies. Sections of ovary, granulosa and neonatal porcine uterine cells were also collected to use as controls.Using both semi-quantitative and quantitative PCRs, relaxin transcripts were not detected in all tested samples, while RXFP1 and RXFP2 mRNA were present. Both receptor gene products were found at higher levels in oocytes compared to cumulus cells, irrespective of the maturation time. Cleaved-embryos contained higher levels of RXFP2 mRNA, whereas, blastocysts were characterized by a higher RXFP1 mRNA content. Using western-immunoblotting or in situ immunofluorescence, relaxin and its receptor proteins were detected in all samples. Their fluorescence intensities were consistently more important in mature oocytes than immature ones. The RXFP1 and RXFP2 signal intensities were mostly located in the plasma membrane region, while the relaxin ones appeared homogeneously distributed within the oocytes and embryonic cells. Furthermore, spermatozoa displayed stronger RXFP2 signal than RXFP1 after western-immunoblotting.All together, our findings suggest potential roles of relaxin and its receptors during oocyte maturation, early embryo development, and beyond.The inadequate culture conditions greatly limit the production of high quality embryos [1,2]. In vivo, maturing gametes and developing embryos maintain complex interactions with their immediate environments which are rich in a variety of molecules such as relaxin, whose embryotrope effects are not completely understood [3,4]. Relaxin is a small peptide (≈ 6 kDa
Relaxin Signals through a RXFP1-pERK-nNOS-NO-cGMP-Dependent Pathway to Up-Regulate Matrix Metalloproteinases: The Additional Involvement of iNOS
Bryna Suet Man Chow, Elaine Guo Yan Chew, Chongxin Zhao, Ross A. D. Bathgate, Tim D. Hewitson, Chrishan S. Samuel
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042714
Abstract: The hormone, relaxin, inhibits aberrant myofibroblast differentiation and collagen deposition by disrupting the TGF-β1/Smad2 axis, via its cognate receptor, Relaxin Family Peptide Receptor 1 (RXFP1), extracellular signal-regulated kinase (ERK)1/2 phosphorylation (pERK) and a neuronal nitric oxide (NO) synthase (nNOS)-NO-cyclic guanosine monophosphate (cGMP)-dependent pathway. However, the signalling pathways involved in its additional ability to increase matrix metalloproteinase (MMP) expression and activity remain unknown. This study investigated the extent to which the NO pathway was involved in human gene-2 (H2) relaxin's ability to positively regulate MMP-1 and its rodent orthologue, MMP-13, MMP-2 and MMP-9 (the main collagen-degrading MMPs) in TGF-β1-stimulated human dermal fibroblasts and primary renal myofibroblasts isolated from injured rats; by gelatin zymography (media) and Western blotting (cell layer). H2 relaxin (10–100 ng/ml) significantly increased MMP-1 (by ~50%), MMP-2 (by ~80%) and MMP-9 (by ~80%) in TGF-β1-stimulated human dermal fibroblasts; and MMP-13 (by ~90%), MMP-2 (by ~130%) and MMP-9 (by ~115%) in rat renal myofibroblasts (all p<0.01 vs untreated cells) over 72 hours. The relaxin-induced up-regulation of these MMPs, however, was significantly blocked by a non-selective NOS inhibitor (L-nitroarginine methyl ester (hydrochloride); L-NAME; 75–100 μM), and specific inhibitors to nNOS (N-propyl-L-arginine; NPLA; 0.2–2 μM), iNOS (1400W; 0.5–1 μM) and guanylyl cyclase (ODQ; 5 μM) (all p<0.05 vs H2 relaxin alone), but not eNOS (L-N-(1-iminoethyl)ornithine dihydrochloride; L-NIO; 0.5–5 μM). However, neither of these inhibitors affected basal MMP expression at the concentrations used. Furthermore, of the NOS isoforms expressed in renal myofibroblasts (nNOS and iNOS), H2 relaxin only stimulated nNOS expression, which in turn, was blocked by the ERK1/2 inhibitor (PD98059; 1 μM). These findings demonstrated that H2 relaxin signals through a RXFP1-pERK-nNOS-NO-cGMP-dependent pathway to mediate its anti-fibrotic actions, and additionally signals through iNOS to up-regulate MMPs; the latter being suppressed by TGF-β1 in myofibroblasts, but released upon H2 relaxin-induced inhibition of the TGF-β1/Smad2 axis.
Fast NO2 retrievals from Odin-OSIRIS limb scatter measurements
A. E. Bourassa, C. A. McLinden, C. E. Sioris, S. Brohede, A. F. Bathgate, E. J. Llewellyn,D. A. Degenstein
Atmospheric Measurement Techniques (AMT) & Discussions (AMTD) , 2011,
Abstract: The feasibility of retrieving vertical profiles of NO2 from space-based measurements of limb scattered sunlight has been demonstrated using several different data sets since the 1980's. The NO2 data product routinely retrieved from measurements made by the Optical Spectrograph and InfraRed Imaging System (OSIRIS) instrument onboard the Odin satellite uses a spectral fitting technique over the 437 to 451 nm range, over which there are 36 individual wavelength measurements. In this work we present a proof of concept technique for the retrieval of NO2 using only 4 of the 36 OSIRIS measurements in this wavelength range, which reduces the computational cost by almost an order of magnitude. The method is an adaptation of a triplet analysis technique that is currently used for the OSIRIS retrievals of ozone at Chappuis band wavelengths. The results obtained are shown to be in very good agreement with the spectral fit method, and provide an important alternative for applications where the computational burden is very high. Additionally this provides a baseline for future instrument design in terms of cost effectiveness and reducing spectral range requirements.
Silencing Relaxin-3 in Nucleus Incertus of Adult Rodents: A Viral Vector-based Approach to Investigate Neuropeptide Function
Gabrielle E. Callander, Sherie Ma, Despina E. Ganella, Verena C. Wimmer, Andrew L. Gundlach, Walter G. Thomas, Ross A. D. Bathgate
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042300
Abstract: Relaxin-3, the most recently identified member of the relaxin peptide family, is produced by GABAergic projection neurons in the nucleus incertus (NI), in the pontine periventricular gray. Previous studies suggest relaxin-3 is a modulator of stress responses, metabolism, arousal and behavioural activation. Knockout mice and peptide infusions in vivo have significantly contributed to understanding the function of this conserved neuropeptide. Yet, a definitive role remains elusive due to discrepancies between models and a propensity to investigate pharmacological effects over endogenous function. To investigate the endogenous function of relaxin-3, we generated a recombinant adeno-associated viral (rAAV) vector expressing microRNA against relaxin-3 and validated its use to knock down relaxin-3 in adult rats. Bilateral stereotaxic infusion of rAAV1/2 EmGFP miR499 into the NI resulted in significant reductions in relaxin-3 expression as demonstrated by ablation of relaxin-3-like immunoreactivity at 3, 6 and 9 weeks and by qRT-PCR at 12 weeks. Neuronal health was unaffected as transduced neurons in all groups retained expression of NeuN and stained for Nissl bodies. Importantly, qRT-PCR confirmed that relaxin-3 receptor expression levels were not altered to compensate for reduced relaxin-3. Behavioural experiments confirmed no detrimental effects on general health or well-being and therefore several behavioural modalities previously associated with relaxin-3 function were investigated. The validation of this viral vector-based model provides a valuable alternative to existing in vivo approaches and promotes a shift towards more physiologically relevant investigations of endogenous neuropeptide function.
Comparison of Straight and Helical Nanotube Production in a Swirled Fluid CVD Reactor
Graham Bathgate,Sunny Iyuke,Frank Kavishe
ISRN Nanotechnology , 2012, DOI: 10.5402/2012/985834
Abstract: Research into Carbon Nanotubes and their applications is fast becoming an extremely popular topic, and any means to greatly improve the synthesis process has a huge marketability. While investigating the feasibility of continuous production of single-walled carbon nanotubes in a vertical Swirled Fluid Chemical Vapour Deposition (CVD) reactor, it was discovered that helical nanotubes were lifted from the reactor by the gas current while straight tubes remained behind. Investigation into the merits provided by the helical structure illustrated the greatly increased likeliness for helical tubes to be lifted from the reactor by the carrier gas giving rise to positive speculation of their possible use in vertical CVD reactors in the future. 1. Introduction CNTs are allotropes of carbon with a nanostructure that can have a length-to-diameter ratio as large as 28,000,000?:?1, which is unequalled by any other material [1]. The small dimensions, strength, and the remarkable physical properties of these structures allow for a very unique material with a whole range of promising applications [2]. The discovery of single-walled carbon nanotubes (SWCNTs) proved to be an extremely important development since the structures appeared to be approximate to those of the “ideal” nanotubes [3] consisting of tubes with walls only one atom thick. To use Paradise and Goswami’s [4] description: “Ideal Nanotubes can be described as a seamless cylinder of rolled up hexagonal networks of carbon atoms.” They also describe possible applications ranging from semiconductors, electronic memory, drive products, and medical delivery systems to uses in plastics such as automobile body panels, paint, tires, and as flame retardants in polyethylene and polypropylene. As SWCNTs are of such importance, there is much marketability for any means by which to improve their synthesis. The best means by which to do this is by developing a fully continuous process. While this process could provide a means to produce larger quantities of SWCNTs, separation and purification is still expensive and so any advantage that results in a purer sample is very desirable. In a vertical reactor, very little is known about the factors that affect which nanotubes will be lifted from the reactor which gives rise to the possibility that given more knowledge, control of certain factors such as shape may provide the means to produce purer products. 2. Process Overview SWCNTs are a very important variety of carbon nanotube because they possess important electronic properties that the multiwalled carbon nanotube (MWCNT)
Evolution of the relaxin-like peptide family
Tracey N Wilkinson, Terence P Speed, Geoffrey W Tregear, Ross AD Bathgate
BMC Evolutionary Biology , 2005, DOI: 10.1186/1471-2148-5-14
Abstract: Sequence similarity searches of genomic and EST data identified homologs of relaxin-like peptides in mammals, and non-mammalian vertebrates such as fish. Phylogenetic analysis was used to resolve the evolution of the family. Searches were unable to identify an invertebrate relaxin-like peptide. The published relaxin cDNA sequence in the tunicate, Ciona intestinalis was not present in the completed C. intestinalis genome. The newly discovered relaxin-3 is likely to be the ancestral relaxin. Multiple relaxin-3-like sequences are present in fugu fish (Takifugu rubripes) and zebrafish (Danio rerio), but these appear to be specific to the fish lineage. Possible relaxin-1 and INSL5 homologs were also identified in fish and frog species, placing their emergence prior to mammalia, earlier than previously believed. Furthermore, estimates of synonymous and nonsynonymous substitution rates (dN/dS) suggest that the emergence of relaxin-1, INSL4 and INSL6 during mammalia was driven by positive Darwinian selection, hence these peptides are likely to have novel and in the case of relaxin-1, which is still under positive selection in humans and the great apes, possibly still evolving functions. In contrast, relaxin-3 is constrained by strong purifying selection, demonstrating it must have a highly conserved function, supporting its hypothesized important neuropeptide role.We present a phylogeny describing the evolutionary history of the relaxin-like peptide family and show that positive selection has driven the evolution of the most recent members of the family.The relaxin-like peptide family includes: relaxin-1, relaxin-2, relaxin-3, and the insulin-like (INSL) peptides, INSL3, INSL4, INSL5 and INSL6. All share high structural similarity with insulin due to the presence of six cysteine residues, which confer two inter-chain and one intra-chain disulfide bonds. Thus, it was postulated that relaxin and insulin had derived from a common ancestral gene and were therefore grouped as th
Characterization of Odin-OSIRIS ozone profiles with the SAGE II dataset
C. Adams,A. E. Bourassa,A. F. Bathgate,C. A. McLinden
Atmospheric Measurement Techniques Discussions , 2013, DOI: 10.5194/amtd-6-1033-2013
Abstract: The Optical Spectrograph and InfraRed Imaging System (OSIRIS) on board the Odin spacecraft has been taking limb-scattered measurements of ozone number density profiles from 2001–present. The Stratospheric Aerosol and Gas Experiment II (SAGE II) took solar occultation measurements of ozone number densities from 1984–2005 and has been used in many studies of long-term ozone trends. We present the characterization of OSIRIS SaskMART v5.0x against the new SAGE II v7.00 ozone profiles for 2001–2005, the period over which these two missions had overlap. This information can be used to merge OSIRIS and other satellite ozone measurements with SAGE II into a single ozone record from 1984 to the present. Coincident measurement pairs were selected for ±1 h, ±1° latitude, and ±500 km. The absolute value of the resulting mean relative difference profile was < 5% for 13.5–54.5km and < 3% for 24.5–53.5 km. Correlation coefficients R > 0.9 were calculated for 13.5–49.5 km, demonstrating excellent overall agreement between the two datasets. Coincidence criteria were relaxed to maximize the number of measurement pairs and the conditions under which measurements were taken. With the broad coincidence criteria, good agreement (< 5%) was observed under most conditions for 20.5–40.5 km. However, mean relative differences do exceed 5% under several cases. Above 50 km, differences between OSIRIS and SAGE II are partly attributed to the diurnal variation of ozone. OSIRIS data are biased high compared with SAGE II at 22.5 km, particularly at high latitudes. The OSIRIS optics temperature is low (< 16 °C) during May–July, when the satellite enters the Earth's shadow for part of its orbit. During this period, OSIRIS measurements are biased low by 5–12% for 27.5–38.5 km. Biases between OSIRIS ascending node (northward equatorial crossing time ~ 18:00 LT) and descending node (southward equatorial crossing time ~ 06:00 LT) measurements are also noted under some conditions. This work demonstrates that OSIRIS and SAGE II have excellent overall agreement and characterizes the biases between these datasets.
Page 1 /479635
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.